Unsaturated Polyesters in Microbial Fuel Cells and Biosensors

CHAPTER

UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS AND BIOSENSORS

21

N. Saranya1, J. Jayapriya1 and V. Ramamurthy2 1

Department of Applied Science and Technology, A.C. Tech., Anna University, Chennai, India 2Department of Biotechnology, PSG College of Technology, Coimbatore, India

21.1 INTRODUCTION Polymer products can be stiff, hard, tough, lightweight, plastic, and flexible. They have a wide range of applications because of their low cost, and they each have distinct thermal, electrical, and optical characteristics [1,2]. Polymer matrix composites (PMCs) comprise a variety of short or continuous fibers (reinforcement) bound together by a thermoset or thermoplastic polymer matrix. The primary function of the matrix is to bond the fibers together and to transfer mechanical loads between them. Reinforcements in PMCs provide high strength and stiffness, while reinforcements in ceramic matrix composites improve fracture toughness. Thermosetting resins that are commonly used in fiber-reinforced plastics include polyesters, vinyl esters, epoxies, bis-maleimides, and polyamides [3]. Examples of thermoplastic resins (also called engineering plastics) are polyesters, polyether imide, polyamide imide, polyphenylene sulfide, polyether-ether ketone, and liquid crystal polymers [4]. The properties of PMCs mainly depend on the matrix, reinforcement, and doping agents employed. Various composite processing techniques such as resin transfer molding, hand lay-up, and spray-up are used for fabrication. These PMCs have certain characteristics including (1) high specific strength and high specific modulus; (2) good fatigue resistance and high damage tolerance; (3) good damping characteristics; (4) superior electric insulation performance and high frequency dielectric properties, (5) high corrosion and friction resistance; and (6) high thermal shock resistance and good abrasion resistance [5]. Polyester resins are unsaturated synthetic resins formed by condensation polymerization of dibasic organic acids and polyhydric alcohols. Typical polyols used are glycols such as ethylene glycol (EG), while the most typically used acids used are phthalic acid, isophthalic acid, and maleic acid. Polyester resins are thermosetting polymers and are highly viscous. The average molecular weight of polyester derived from orthophthalic acid is in range of 800 1000 g/mol and for isophthalic acid the range is 1500 2000 g/mol. Most of the polyester resins typically contain an equal volume percentage of monomers like styrene [6]. The unsaturated polyester (UP)/styrene ratio alters the viscosity and cross-linking degree of resins, which can find their way into different industrial applications such as coatings, automotive, transportation, storage tanks, and piping.

Unsaturated Polyester Resins. DOI: https://doi.org/10.1016/B978-0-12-816129-6.00021-1 © 2019 Elsevier Inc. All rights reserved.

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Glass fiber reinforced polyester resins have been utilized for decades in many applications including automotive and construction due to their good cost properties relation. However, the mechanical strength and thermal stability of polyester resin is low compared to other resins. Also, it is electrically insulating in nature which hinders some of its applications. To overcome this shortcoming, several other fillers like silicates, clay, carbon fibers, and carbon nanotubes (CNTs) have been incorporated to improve the properties of polyester resins. George et al. [6] prepared cross-linked polyester clay nanocomposites by dispersing aminemodified kaolite and cross-linking by methyl ethyl ketone peroxide catalyst. These nanocomposites showed better improvement in thermal and mechanical properties. However, the oxygen permeability of the composite was found to be reduced progressively. The tensile strength and toughness of the composite was maximum at 1-phr of clay in 100 g of UP and the storage modulus showed an improvement of 38% compared to neat unsaturated polyester resin (UPR). Sreekumar et al. [7] fabricated a polyester composite using sisal fiber reinforcement, which offered specific characteristics such as higher dielectric constant and conductivity. Asimakopoulos et al. [8] developed a nanocomposite polyester matrix embedded with barium titanate (BaTiO3) nanoparticles. The BaTiO3 increased the energy storage capacity. Nickel polyester composites and nickel polyester composites modified with cobalt catalysts were prepared by D´avila Jim´enez et al. [9] and they were tested as electrodes for oxygen evolution reactions in alkaline environments. Kanimozhi et al. [10] modified commercially available polyester resins with vinyl-functionalized rice husk ash (VRHA) as a silica source using benzoyl peroxide as a curing agent. The VRHA-reinforced composites exhibited the unique characteristic of hydrophobicity and could be used as water-repelling coatings. Li et al. [11] synthesized carborane-containing polyesters with high thermostability by the catalytic polycondensation of carborane diol monomers with carborane diacid chlorides. These can be used in high temperature resistant coatings and adhesives. Macasaquit et al. [12] prepared a conducting polyester textile composite through the in situ polymerization of pyrrole. The polyester composite exhibited a high conductivity when the polyester textiles were soaked in a 50% aqueous pyrrole solution. Tunakova et al. [13] prepared polyester (PET) polypyrrole polymer composites having distinct characteristic features of electromagnetic shielding and antielectrostatic property. Khan et al. [14] prepared UP Ce (IV) phosphate, and it could be used as an effective cation exchanger for the removal and recovery of malachite green from wastewater. Seyhan et al. [15] reported the preparation of CNT/unsaturated thermoset polyester nanocomposites using 3-roll mill and sonication techniques. The CNT/polyester blend exhibited shear thinning, good dimensional stability, and low moisture behavior. CNT polyester multifilament yarns with an electrical resistivity level of 109 ohm/cm were used for making brushes for photocopy machines due to their excellent static-control performance. Ayoub et al. [16] prepared an enzyme-dispersed multiwalled carbon nanotube (MWCNT)/polyester electrode for dye sensitized solar cells. These composites possessed high conductivity, low charge transfer resistance, and excellent redox behavior when compared to commercial platinized fluorine doped tin oxide electrodes, suggesting that they could be used in wearable e-textile based photovoltaic systems. Carbon materials were impregnated into woven cotton and polyester fabrics using a screen printing technique by Jost et al. [17] and the porous structure of such composites made them very attractive materials for supercapacitors. Similarly, polyester has been used as a base for loading electrochemically active species like CNTs [18 20] and polymers like polyaniline and polypyrrole [21,22] to increase the energy

21.2 APPLICATION OF UNSATURATED POLYESTER

559

storage capacity for supercapacitor applications. Dom´enech et al. [23] prepared graphite polyester composite electrodes through a copolymerization reaction using the catalyst cobalt octoate, and they can be used as the sensor component for identification of iron oxide in the sample. Lu et al. [24] prepared UPR/graphite nanosheet conducting composites characterized by an extremely low percolation threshold. Huang et al. [25] developed polyester/graphite/glass fiber polymer composite bipolar plates by compression molding and examined the performance of these conductive composites in proton exchange membrane (PEM) fuel cells. Improvements in the mechanical properties such as flexural, tensile, and impact strength were observed and it was also found that these composites are cost effective. Thus polyester resins have numerous advantages and are able to support a broad variety of fillers in PMCs, which make them suitable for a wide range of applications. This chapter is concerned with the application of UPRs in microbial fuel cells (MFCs) and biosensors.

21.2 APPLICATION OF UNSATURATED POLYESTER IN MICROBIAL FUEL CELLS 21.2.1 UNSATURATED POLYESTER AS ELECTRODE MFCs are bioelectrochemical transducers that convert microbial reducing power (generated by the metabolism of organic/inorganic substrates) into electrical energy [26,27]. A current is generated by microbial action in the vicinity of the anode, resulting in the conduction of electrons by the circuit, while the protons generated in the process are mobilized across the membrane separating the chambers to be oxidized at the cathode. A basic H-shaped MFC design is shown in Fig. 21.1. Unlike chemical fuel cells, biological fuel cells operate under mild reaction conditions, namely ambient operational temperature, pressure, and near neutral pH. There are three ways by which microorganisms can transfer electrons to the anode namely (1) through exogenous mediators such as potassium ferricyanide, thionine, or neutral red [28 31]; (2) by producing mediators by themselves [32]; or (3) by direct transfer of electrons from respiratory enzymes (i.e., cytochromes) to the electrode [33]. Electron-transfer mediators shuttle electrons between the microbial biocatalytic system and the electrode. There are several drawbacks to using exogenous mediators such as their expense, short lifetime, and toxicity to microorganisms. In recent years, the potential of MFCs to be deployed for wastewater treatment along with other possibilities such as energy generation, biohydrogen production, sensing necessary process parameters, and bioremediation or desalination have been investigated [34,35]. Although these are theoretical constructs, many impediments remain. While there are many factors that play important role in a given process, MFC performance is particularly sensitive to the microbial composition relating to the waste to be treated, the electrode composition, the separation of the electrode chambers, and the overall system configuration all of which have to help overcome high internal resistance to generate adequate power. Among the several components that influence power generation in MFCs, the composition of the electrodes is perhaps the most important. High efficiency electrodes such as metal coated carbon polymer composites and noble-metal catalysts are used in conventional fuel cells, although commercially available products are not particularly suitable for MFCs. These electrodes are not biocompatible and are susceptible to catalyst poisoning when industrial effluents used. There is a

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FIGURE 21.1 Representation of an H-shaped microbial fuel cell.

need for the development of electrode materials (anode) unique for MFCs that are cheap, easy to process, biocompatible, noncorrosive, with suitable redox behavior for microbial metabolism, and scalable. These cathode materials must facilitate high oxygen reduction and, hence, high redox potential such as metals. Electrocatalytic polymers such as polypyrrole, polyaniline/Pt composites, and CNTs have been shown to improve the current generation by facilitating the direct oxidation of microbial metabolites [36,37]. Carbon electrodes have some specific advantages, including a wide potential window, low residual current, long term stability, excellent biocompatibility, high electrical conductivity, relatively high chemical stability, high corrosion resistance, low density, low thermal expansion, and low cost [38]. Carbon being one of the most allotropic materials offers a variety of physicochemical properties due to its structural variations, and hence by modifying its surface, properties suitable for MFC can be engineered [39]. Polymers like nafion, epoxy resin, polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyvinyl alcohol, and polyester resin have been reported as binders for composite electrodes [40]. These polymers are mainly used to provide binding strength between redox species (metal salts) and active materials (graphite, CNTs, etc.), leading to higher composite stiffness and strength as well as reducing manufacturing costs. Lowy et al. [39] tested several formulations of graphite electrodes doped with anthraquinone1,6-disulfonic acid and 1,4-naphthoquinone, a graphite ceramic composite containing Mn21 and Ni21, and a graphite paste containing Fe3O4 and Ni21. The authors found that modified electrodes showed power outputs four to five times higher than those of unmodified electrode. Park and

21.2 APPLICATION OF UNSATURATED POLYESTER

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Zeikus, by incorporating Mn41 into the anode, reported a maximum power density of 788 mW/m2 [41]. Jayapriya et al. [42,43], using epoxy resin at 24% (w/w) as a binder, showed that the catalytic performance of graphite epoxy doped electrodes with different metal salts reduced the internal resistance of the MFC. Similarly, UPRs were used as a binder in graphite electrode preparation by Saranya et al. [40] with metal salts as dopants. Polyester resins are thermosetting polymers that can be molded, cast, or laminated at low pressure and temperature. These resins cure quickly at room temperature, have high chemical resistance, and are cost effective. Saranya et al. [40] molded electrodes by mixing graphite with metal salts. While the former served as the conductive material, the later was the redox shuttle. UPR with a cobalt octanoate accelerator served as the resin and the polymerization was initiated by methyl ethyl ketone peroxide. An equal volume mixed slurry was molded into 35 3 10 3 10 mm rods, cured at room temperature for 36 hours, and washed in acetone and ethanol. The addition of 50% polyester matrix reduced the conductivity from 6.1 3 1023 S/m of pristine graphite to 2.8 3 1023 S/ m for the composite. This may be attributable to the polyester layer surrounding the graphite particles, thereby forming a tunneling barrier against electrical transport. The metal salts appeared to aid in the percolation of electrons as suggested by the increased conductivity observed in these composites. The increase in conductivity of the composite would depend on the electron affinity of the salts as well as the ionization potential of the bulk polymer. The electrochemical stability of the composites was determined using cyclic voltammetry, and were found to exhibit up to 80% 85% retention even after 50 cycles. They were found to be highly stable composite electrodes as is essential for MFC applications. In graphite polyester composite electrodes (GPECEs), doped with salts of Fe, Ni, or Zn there appeared to have more pores and improved surface as indicated by the reduced pore resistance below 10 kΩ and better biofilm formation. These were perhaps the reasons for the improvement in power densities. For example, among the different combinations of electrodes that were tested in MFCs, the best performing MFC with the highest power density (1575 6 223.26 μW/m2) was seen with Ni-GPECE as the cathode and a graphite block as an anode compared to the unmodified counterparts, that is, graphite blocks (95.83 6 4.10 μW/m2) versus GPECE (127.07 6 7.09 μW/m2). Polyester is a well-known synthetic fiber that can be spun into yarn and knit as a fabric, and used as support material in the fabrication of electrodes for MFC. The fabric can provide a greater surface area compared to sheets or plates. Polyester is a low conductive material, nevertheless it could act as the base support for the fabrication of modified graphite electrodes. This support material offers mechanical stability as well as chemical resistance for long term operations of MFCs in extreme environments. A single chamber air-cathode MFC with double cloth electrode assembly (DCEA) was designed by Fan et al. [44]. The cloth electrode assembly (CEA) was nonwoven cloth containing 25% polyester and had excellent physical strength as well as chemical and biological stability. No defects in the CEA were observed over a long period of time (4 years) and the authors claimed that this novel material for use in MFCs was stable in the highly corrosive alkaline environments they worked with. The architecture of DCEA MFCs offers unique advantages such as: (1) reduced electrode spacing which may lead to a decrease in the internal resistance of the cell and perhaps enhanced cell performance, and (2) oxygen crossover can be effectively suppressed by a low-cost nonwoven cloth. It is known that nano-/microscale pores in anode materials are easily clogged by microbes and hinder the diffusion of the substrate. Hence, efforts are focused on fabricating structures that would

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overcome concentration polarization losses. Xie et al. [45] fabricated electrodes by coating microscale porous CNTs on a macroscale porous textile which was made by randomly intertwined polyester fibers with a diameter 20 μm. They found that the macroscale porous polyester fibers created a 3D space (to the order of 100 μm), which was designed to increase the rate of substrate diffusion. The macroscale polyester fibers may lead to high colonization of microorganisms, while the microscale porous CNTs enhanced the charge transfer between electrode and electroactive biofilms. The CNT textile was conductive (50 S/cm), chemically and mechanically stable, biocompatible and lightweight, suggesting that this material has great promise for large-scale industrial applications [45]. They tested the CNT textile as an anode in an MFC and observed that the maximum current density was 7.2 A/m2, which was 2.6 times higher as compared to carbon cloth anodes (2.8 A/m2). Thus the CNT textile anode improved the MFC performance. This suggests that the coating of CNT was an important transporter of electrons between the biofilm and the textile base. In the past few decades, extensive efforts have been made to miniaturize standard macrosized MFCs using micro-/nanofabrication technologies. Pang et al. [46] designed a flexible, stretchable, miniaturized MFC using a textile material (92% polyester and 8% spandex). Textiles can be used as a support material due to their unique properties such as (1) their easily patternable structure, from hydrophobic to hydrophilic, (2) intrinsic macroporous structure and large surface area, and (3) their capability of self-repair and self-assembly when subjected to continuous deformation from bending, twisting, and stretching. In a generally hydrophobic material, Pang et al. dispersed the conductive polymers, poly (3,4-ethylene dioxy thiophene) (PEDOT) and polystyrene sulfonate (PSS) to increase biofilm adhesion, meanwhile the surface hydrophilic properties of the textile material were improved by the addition of EG and 3-glycidoxypropy-trimethoxysilane. When bacteria containing liquid was poured into the anode (EG-modified PEDOT PSS textile material), a maximum power density of 1.0 μW/cm2 was obtained in pseudomonas catalyzed MFC. In these experiments, Pang et al., employed Ag2O textile material as a cathode. This solid electron acceptor enhanced the oxygen reduction rate in the cathode chamber, thereby reducing the cathodic overpotential of the MFC. Davis et al. [47] spray painted a polyester support material for the fabrication of electrodes. Hu et al. [48] fabricated a conductive woven polyester fabric by dipping the fabric into an aqueous single-walled carbon nanotube (SWCNT) ink followed by drying in oven at 120 C for 10 minutes. Xie et al. [49] deposited Pt nanoparticles by electrodeposition onto macroporous SWCNT conductive textile fabric, which was prepared by Hu et al., and evaluated the performance of CNT textile Pt in an MFC. The CNT textile Pt cathode showed a maximum power density (559 mW/m2) 2.14-fold higher than that of a CNT Pt cathode (391 mW/m2), which suggests that the CNT textile Pt had a higher surface area and more porous network. Moreover, the synthetic process for CNT textile Pt is simple and scalable, therefore it could be considered as a promising electrode material for use in MFCs. Zuo et al. [50] evaluated tubular cathodes, which can increase the surface to volume ratio for MFC applications. Co-tetra-methyl phenylporphyrin (CoTMPP) coated hydrophilic tubular membrane (a polysulfone membrane on a composite polyester carrier) was used as the cathode in MFC to improve the performance of oxygen reduction reaction (ORR). The coulombic efficiency increased by about 25% 40% for tubular cathode, compared to the 7% 19% increase with a carbon paper cathode. This UF hydrophilic tubular membrane reduced the O2 diffusion from the cathode to the anode chamber, so that it overcome the cathode polarization losses in the fuel cell.

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21.2.2 UNSATURATED POLYESTER AS MEMBRANE SEPARATORS A typical MFC consists of anode and cathode compartments, which are separated by a PEM. The role of the membrane is not only to permit the transfer of protons, but also to prevent the mixing of the contents, particularly of oxygen from the cathode compartment to the anode compartment where the protons are generated. The separator in an MFC has to possess certain features, namely an insulator, it has to be ion selective (e.g., proton conducting), durable, chemically stable, biocompatible, resistant to fouling and clogging, and inexpensive. Different kinds of materials have been tried as PEMs in MFCs such as ultrex, Nafion, bipolar membranes, dialyzed membranes, polystyrene and divinyl benzene with sulfuric acid group, glass wool, nanoporous filters, and microfiltration membranes [51]. The most commonly used membrane in MFCs is Nafion, a perfluorosulfonic acid polymer developed by Dupont [52] because of its highly selective permeability of protons and high ionic conductivity (1022 S/cm). It consists of three regions (1) a Teflon-like, fluorocarbon backbone, (2) side chains, O CF2 CF O CF2 CF2 , which connect the molecular backbone to the third 1 2 region, and (3) the ion clusters consisting of sulfonic acid ions, SO2 3 H . A negative ion, SO3 , is permanently attached to the side chain. However, when the membrane becomes hydrated by absorbing water, the hydrogen ion becomes mobile. Ion movement occurs by protons bonded to water molecules, hopping from one SO2 3 site to another within the membrane. Thus solid hydrated electrolyte is an excellent conductor of hydrogen ions. However, the use of Nafion membranes may not be feasible for large-scale commercialization of MFCs for wastewater treatment [53,54] due to its high cost, oxygen permeability [9.3 3 10212 mol/(cm s)] and membrane biofouling which limits proton diffusion. In general, PEMs are expensive and contribute to about 38% of the capital cost of MFCs. Some researchers have reported that the ohmic resistance decreased in an MFC without a separator; however, the diffusion of oxygen from the cathode to anode chamber would lead to the aerobic respiration of bacteria, thereby affecting the coulombic efficiency. Similarly, the diffusion of oxidants from the anode to cathode chamber could also increase the polarization losses in the ORR at the cathode. Cation exchange membranes (CEMs) and anion exchange membranes (AEMs) are less expensive separators for MFCs [55]. However, the transport of cation species other than protons through CEMs, causes a pH imbalance, that is, an increase in the cathode chamber [56]. This pH increase negatively affects MFC performance. Rozendal et al. observed that for every increase of 3 pH units, a potential loss of 0.18 V can occur in the cathode [56]. In the case of an AEM, hydrogen at the cathode was not produced from the proton reduction, but from the reduction of water that diffused through the membrane (2 H2O 1 2e2-2OH2 1 H2). The protons in the anode chamber were consumed by these hydroxyl ions transferred from anode to cathode and thus maintained electroneutrality in the system. However, the pH does increase more in the cathode chamber than with Nafion. The addition of a bicarbonate buffer may be used in the catholyte to stabilize the pH of the cathode chamber and decrease the internal resistance of the MFC. In principle, only membranes that are truly 100% proton selective can prevent pH effects in MFC performance. But these types of membranes are not available at low costs. UF membranes, especially those developed for wastewater applications, have been used as separators in MFCs. Kim et al. [55] tested UF membranes with different molecular weight cut-offs in MFCs and found that these membranes had relatively high internal resistances when compared

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CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

with CEM/AEM. On the other hand, membrane fouling always occurred in the MFCs, as biofilm with extracellular polymers can be formed on PEM during its long-term operation. This would lead to deterioration in the MFC performance [57]. Developing antifouling methods for PEMs with high proton diffusion coefficients at low cost is a priority area. Important parameters such as pore size, porosity, and ion exchange capability determine the behavior of the separator material for MFC applications. Pasternak et al. compared the performance of different kinds of ceramic membranes (alumina, earthenware, mullite, and pyrophyllite), and evaluated their characteristics in a cascade of MFCs [58]. Polyester is also a viable alternative for the conventional membranes used in MFCs, due to its low cost, ease of processing, mechanical stability, and chemical resistance. Kim et al. [59] investigated the performance of single and multiple layer polyester cloth (PC) as an alternative separator to Nafion in MFCs. Double- and triple-layer PCs were prepared by just overlapping layers of PC without any physicochemical treatment and evaluated for their performance in MFCs. A single layer of PC showed a higher oxygen mass transfer coefficient (ko) of 50.0 3 1025 cm/s when compared to the 20.8 3 1025 cm/s obtained with Nafion 424 as the PEM. Increased numbers of PC layers were found to reduce the oxygen mass transfer coefficient, while also reducing the proton transport from the anode to cathode chamber. Moreover, a higher average current density was observed in MFCs with triple layered PC (104.3 6 15.3 A/m3) compared to MFCs with Nafion PEMs (100.4 6 17.7 A/m3). No significant change in the PC surface was observed during 177 days of use with industrial effluents. J-cloth (JC), a macroporous filter, and glass fibers were also tested as separators in MFCs (Table 21.1). JC was found to be less biocompatible [60], while glass fibers were expensive compared to PC. These results suggest that polyester is a good separator material for large scale MFC applications particularly for wastewater treatment. Two layers of textile material (Amplitude Prozorb, Contec Inc.) were used as separators to minimize oxygen crossover and short circuiting between the electrodes [61]. These textile separator materials were made from 46% cellulose and 54% polyester (thickness 0.3 mm; weight 0.55 g/m2) [59,61 68] and their performances in MFCs are shown in Table 21.2. Tartakovsky et al. [69] designed an MFC set up where the compartments were separated by a 3 mm thick polyester pad with a total porosity of 0.93 (Skotch-Brite 3M, St. Paul, MN). The price of polyester can reduce the cost of MFC construction. In separator electrode assembly MFC designs, cloth or porous material placed between the electrodes decreased the ohmic resistance due to an electrode spacing of ,1 cm [60].

Table 21.1 Comparison of Polyester Separator With Other Separators in MFCs Separators; Thickness (cm)

Mass Transfer Coefficient (ko 3 1025 cm/s)

Cost (US$/m2)

References

PEM (Nafion 424); 0.019 Polyester (Single layer); 0.004 Polyester (Double layer); 0.008 Polyester (Triple layer); 0.012 PEM (Nafion 117); 0.019 J-cloth; 0.03 Glass fiber 1.0; 0.1

20.8 50 41.6 23.8 67 290 5

2600 75

[58] [59] [59] [59] [60] [60] [71]

1400 400

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565

Table 21.2 Polyester Separator in Different Forms Used in MFC Configurations Material

Specification

Reference

Amplitude Prozorb, Contec Inc. Spartanburg, South Carolina, USA Skotch-Brite 3 M, St. Paul, Minnesota, USA RAL-EX; Mega Inc., Czechoslovakia

54% Polyester and 46% cellulose (Thickness 0 0.3 mm; weight 0 55 g/m2) Polyester pad (Thickness 3 mm, porosity 0.93)

[59,61 68]

Polyester with polyethylene binder (Thickness 0.45 mM (Dry), size 4.5 cm 3 3.5 cm) Polyester cloth (Thickness 0.5 0.7 mm)

[70]

Commercial polyester cloth

[69]

[72,73]

Pandit et al. [70] tested a polyester separator blended with a polyethylene binder (RALEX AEM-PES) in MFCs. In this case, the membrane diffused the monobasic and dibasic phosphate ions from the cathode to the anode chamber. The protons produced at the anode reacted rapidly with the dibasic phosphate to form monobasic phosphate and then it diffused from the anode to the cathode. The monobasic phosphate released protons to the cathode via diffusion and electron migration, suggesting that the modified polyester anionic membrane reduced the polarization losses.

21.3 APPLICATION OF UNSATURATED POLYESTER IN MEMBRANE BIOREACTOR-MICROBIAL FUEL CELL A MBR is a combination of a microfiltration or UF device with a biological process. In recent years, MBRs have been widely used for industrial wastewater treatment due to their unique advantages like good effluent quality and proper biomass retention. However, practical issues of cost and membrane fouling are still major issues as in any membrane treatment process. According to pore size, the membranes used in MBRs are grouped into three categories, namely dynamic membranes ( . 1 μm), UF (,0.1 μm), and forward osmosis (,1 nm) [74]. Irreversible fouling such as (1) inorganic fouling/scaling, (2) particle/colloids fouling, (3) microbial fouling, and (4) organic fouling are impediments in the use of all types of membranes. Fouling blocks the pores of the membrane and increases the hydraulic resistance accompanied by a decrease in permeate flux and quality. Microbial fuel cell (MFC) is a leading-edge technology that can discharge the dual duty of degrading the pollutants and generating power. However, the treated effluents from MFC operations do not meet the water quality criteria for wastewater reuse. The integration of MFCs with membrane filtration could be a way to sort out this issue. Several attempts have been made to enhance power generation in MFCs by oxidizing organic matter and to achieve a high degree of throughput in wastewater treatment processes by membrane filtration. Membrane modules can be installed either in an internal or external configuration in MFC-MBR integrated units. In an internal configuration, membranes can act as a separator placed between an anode and cathode, or be immersed in the MFC chamber as a filtration component. In external configurations the MFC and the membrane module are operated independently. Like conventional MBRs, membrane fouling will be a significant challenge for MFC-MBR integrated units.

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In recent years, researchers have found many interesting aspects in the MFC-MBR design such as (1) operating the anode chamber of the MFC at low pH reduces the fouling (inorganic fouling compounds are more soluble in acidic environments) when membrane filtration is immersed in the anode chamber. (2) In some cases, the membrane was conductive and was used as a cathode in the MFC-MBR designs, and this revealed that the negative charges that accumulated in the cathode enhanced the electrostatic repulsive force between flocculants and the membrane (cathode), thereby the fouling effect was lowered. (3) Due to the relatively small pore size of the membranes, they could effectively remove volatiles, suspended solids, and pathogens, thereby improving the quality of effluents. (4) MFC-MBR designs reduced the high energy costs for aeration and the need to control membrane fouling in MBRs. More research studies are underway to fabricate membrane electrode (that act as both cathode and filter) materials. Membrane electrodes should be conductive, increase the ORR, have the right pore size to retain toxic compounds, and be resistant to fouling and able to prevent the diffusion of O2 from the cathode to and anode chamber. There are several reports using nonconductive polyester doped with conductive ORR catalysts (platinum, MWCNT) or conductive polymers (polyaniline, polypyrrole). An aerobic MBR with an anthraquinone disulfonate/polypyrrole (AQDS/PPY) modified polyester (PT) flat membrane serving as the cathode of a dual-chamber MFC was developed by Xu et al., [75] for wastewater treatment, energy recovery, and membrane fouling mitigation. Xu et al., modified the PT filter cloth with the conducting anthraquinone disulfonic salt, polypyrrole, and ferric chloride by oxidative polymerization and a composite membrane was prepared. According to Xu et al. [75], this conductive membrane cathode minimized the membrane fouling by: Step 1: Formation of H2AQ by the reduction of PPY-bound AQ molecules, that is, AQ 1 2H 1 1 2e2 -H2 AQ

(21.1)

Step 2: Formation of H2O2 at the cathode via ORR catalyzed by the electro generated H2AQ, H2 AQ 1 O2 -AQ 1 H2 O2 21

Step 3: Formation of Fe by the reduction of Fe the internal electric field of MFC,

31

(21.2)

present in AQDS/PPY composites through

Fe31 1 e2 -Fe21

(21.3)

.

Step 4: Generation of OH radical through Fenton reaction, Fe21 1 H2 O2 -Fe31 1  OH 1

2

OH

(21.4)

These free radicals (H2O2 and OH radicals) on the AQDS/PPY-modified polyester membrane could provide the in situ cleaning of the membrane surface via oxidation. Liu et al. [76] integrated MFC with MBR to design a bioelectrochemical membrane reactor (BEMR) as shown in Fig. 21.2. Liu et al., modified the base polyester filter cloth with more than one layer of polypyrrole through vapor polymerization. Iron anode and modified polyester filter cloth membrane cathode was tested in BEMR. Compared to control MBRs, the membrane fouling in the BEMR was reduced significantly. Electrostatic repulsion by the accumulated negative charges on the cathode and chemical corrosion of the iron anode led to the mitigation of fouling. Katuri et al. [77] combined a microbial electrolysis cell with membrane filtration using electrically conductive, porous, nickel-based polyester hollow-fiber membranes (Ni-HFMs). In the set-up

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567

FIGURE 21.2 Schematic diagram of BEMR ((1) external resistor, (2) iron anode electrode, (3) membrane cathode module, (4) vacuum meter, (5) peristaltic pump, (6) aerators). Reproduced by permission of Elsevier; J. Liu, L. Liu, B. Gao, F. Yang, Integration of bio-electrochemical cell in membrane bioreactor for membrane cathode fouling reduction through electricity generation, J. Membr. Sci. 430 (2013) 196 202. https://doi.org/ 10.1016/j.memsci.2012.11.046.

of this anaerobic electrochemical membrane bioreactor, the Ni-HFM could function both as the cathode for hydrogen evolution reaction and the membrane for effluent filtration. The authors found that hydrogen bubble formation, low cathode potential, and localized high pH at the cathode reduced membrane fouling. In addition to this, chemical oxygen demand (COD) was also reduced significantly. Malaeb et al. [78] modified a nonconductive polyester nonwoven membrane by coating with MWCNTs to produce a membrane/biocathode assembly in MFC-MBR. This design produced low power density (0.38 W/m2) when compared to MFC using Pt electrode (0.82 W/m2). However, the effluent quality from the MFC-MBR was comparable to that of conventional MBR (97% COD removal), suggesting that MFC-MBR would be economically feasible for treating wastewater without the aid of aeration. Li et al. [79] prepared an electrically conductive membrane cathode by coating a polyester filter cloth with graphene (Gr) and polyaniline (PANi) doped with phytic acid (PA). The Gr/PANi-PA membrane had a good conductivity and an excellent antifouling property. The maximum power density attained in the MFC-MBR was 44.80 mW/m2. The authors also examined the effect of an external electric field on the fouling effect of the Gr/PANi-PA membranes. The permeate volume from the Gr/PANi-PA membrane increased by B58% after applying a 0.2 V/cm electric field, while only an B10% increase was observed for the PANi-PA membrane. These results suggest that membranes with high conductivity suppress the deposition of particles on the surface of the membrane. Yu et al. [80] tested PANi-modified polyester filter membrane as both anode and cathode and it produced the highest power density (135 mW/m2) in an integrated MFC-MBR system. The authors coated carbon foam-Fe-Co catalyst on the PANi-modified polyester filter membrane and tested it as a cathode. It increased the power density by 38.5-fold. The different cathode separators used in

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CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

Table 21.3 Polyester as Cathodic Separator in MFC-MBR Material

Functionalization of Polyester Electrode

Reference

AQDS/PPY/polyester filter membrane Polypyrrole/polyester filter cloth

Anthraquinone disulfonate doped polypyrrole by chemical oxidative polymerization on polyester fiber cloth Chemical oxidative polymerization of polypyrrole on polyester filter cloth Multiwalled carbon nanotubes coated on Polyester filter membrane In situ liquid polymerization of polyaniline phytic acid on polyester filter cloth Chemical polymerization of polyaniline on filter cloth In situ polymerization of phytic acid-doped polyaniline on Gr coated filter cloth

[75]

Multiwalled carbon nanotubes/ polyester nonwoven membrane base Polyaniline phytic acid modified filter electrode PANi/polyester filter electrode Graphene/PANi-phytic acid cathodic filter membrane

[76] [78] [79] [80] [81]

MFC-MBR are shown in Table 21.3. These studies show that modified polyester filter membranes are a cost effective and scalable approach to waste treatment using MFCs.

21.4 APPLICATION OF UNSATURATED POLYESTER IN BIOSENSORS A biosensor is an analytical device used for the detection of an analyte that combines a biological element with a transducer or detector element (Fig. 21.3). Different sensitive biological elements including organisms, tissues, microorganisms, organelles, cell receptors, enzymes, antibodies, and nucleic acids can be used based on their interaction with the analyte for detection. The transducer is an element that transforms one signal into another that works in a physicochemical way such as optical, piezoelectric, electrochemical, electrochemiluminescent, etc., resulting from the interaction of the analyte with the biological element for the purpose of facile measurement and quantification. Selectivity, sensitivity, response time, detection limit, ruggedness, recovery time, reproducibility, storage, and operation stability are desirable characteristics that biosensors should exhibit. In this chapter, only bioelectrochemical transducers are considered, particularly in reference to the applicability of UPR as a component of electrode materials. The performance characteristics of fabricated biosensors are controlled by (1) the method of biocatalyst immobilization and (2) the binding force between the biomolecule and electrode surface. The electrode material used for the immobilization of biorecognition molecules in a biosensor should be such that it provides a good electron transport capacity. Commonly used methods for the immobilization of receptors include physical entrapment, physical adsorption, covalent binding, and cross-linking using multifunctional reagents and electropolymerization. Thus different strategies can be used in the construction of a biosensor to facilitate direct electron transfer including the application of mediator-modified enzymes, electrodes modified by the membrane, by conducting or nonconducting-polymer matrices, sol gel-based supports, hydrogel supports, screen printed support or use of nanoparticles as electrode materials.

21.4 APPLICATION OF UNSATURATED POLYESTER IN BIOSENSORS

569

FIGURE 21.3 General schematic representation of biosensors.

Membrane-based biosensors provide an inexpensive, portable, rapid, and disposable option for quantitative determination of analytes. They also help in maintaining enzymatic stability and provide an increased shelf-life to the biosensor. In addition to this, they also solve various limitations such as the direct enzymatic immobilization to the transducer, prevents loss of enzyme, and allow for mass production and a reduction in time of the enzymatic response, thus improving the reproducibility of the biosensor signals. Organic membranes are more commonly used for biosensor applications than inorganic membranes. Membranes are generally used as a support structure, but they may also be used as an integral component of the sensing process. Membranes have been made with polyester, PES, polydimethylsiloxane, nylon, polypropylene, PLA nanofibers, cellulose, polycarbonate, polyacrylamide, cellulose acetate, polyvinyl chloride, polyamine/polyurethane, and PVDF [82,83]. The porous structure of membranes can be used to immobilize enzymes in close proximity to the electrode surface in biosensors. Polymers are useful in the field of electronic measuring devices, especially in biosensors, due to their ability to form kink selective coatings on the surface of working electrodes which reduce or prevent interfering compounds from penetrating into the sensing layer on the surface of the electrode. These polymeric matrices are flexible, biocompatible, and are comparatively inexpensive. Polyesters are commonly used as a base material due to their ease of preparation, chemical inertness, tunable porosity, high photochemical and thermal stability, prevention of leakage of enzymes, and biocompatibility. They are also highly resistant to stretching and shrinking as well as the fact that the physical characteristic of the insulating material will remain consistent over longer period of operation helping to improve the reproducibility of biosensor signals. Nonconducting polyester materials possess different functional groups such as amines, carboxylic acids, and thiols [84] so their surfaces can be modified with different oxidizing agents, leading to a variety or higher load of the recognition moiety. However, this support may act as a barrier between the electron and transducer surface, which affects the sensitivity of biosensors. In order to solve this issue, several approaches are underway toward the modification of polyester as a support for biosensor applications.

21.4.1 HUMIDITY SENSORS Sensors developed from textile structures are flexible. De Oliveira et al. [85] developed humidity sensors based on cotton (CO) and polyester knit fabrics functionalized by PANi doped with hydrochloric acid (HCl) and phosphoric acid (H3PO4). Graphite was dispersed onto the polyester fabric, dried, and a conductive polymer, PANi, was deposited onto the knit via in situ deposition and polymerization. These conductive PANi-doped polyester humidity sensors showed good sensitivity and high reversibility characteristics (70% 100%).

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CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

21.4.2 UREASE SENSORS Tiwari et al. [86] designed an amperometric biosensor for the quantitative determination of urea in aqueous media using hematein, a pH-sensitive natural dye. The method for the preparation of the urea sensor [86] is given as: Step 1: Gold nanoparticles embedded with hyperbranched polyester (Boltorns H40 (H40 NH2)) Carboxyl group functionalized gold (Au COOH) nanoparticles 1 amine functionalized hyperbranched polyester, Boltorns H40 (H40 NH2)

(21.5)

a. Carboxyl group functionalized gold (Au COOH) nanoparticles b. Amine group functionalized hyperbranched polyester Boltorns H40 (H40 NH2)

(21.6)

Step 2: Grafting of H40 NH2 onto the Au COOH nanoparticles

(21.7)

Step 3: Preparation of the Au H40/ITO electrode

(21.8)

Step 4: Fabrication of the urea bioactive electrode

(21.9)

H40 Au nanoparticles have been found to be an attractive option for biosensor fabrication because they can be prepared under ambient conditions and they exhibit tunable porosity, high thermal stability, and are chemically inert. The fabricated urea biosensor exhibited a sensitivity of 7.48 nA/mM with a response time of 3 seconds.

21.5 CONCLUSION

571

21.4.3 HORSERADISH PEROXIDASE BIOSENSOR Al-ahmed et al. [87] designed a biosensor to detect hydrogen peroxide which had a sensitivity of 1.33 μA/μM and a detection limit of 0.185 μM for H2O2. First, aniline was electropolymerized inside the interstitial pores of polyester sulfonic acid sodium salt and it was adsorbed onto a Pt disk electrode. Subsequently, horseradish peroxidase was immobilized on this modified electrode for hydrogen peroxide detection.

21.4.4 GLUCOSE OXIDASE BIOSENSOR Pradhan et al. [88] fabricated a glucose biosensor using a two-step procedure. First the electrodeposition of ZnO nanowires (NWs) on the conducting Au-coated polyester substrate was carried out at 70 C in an aqueous electrolyte (zinc nitrate potassium chloride). Second, glucose oxidase (GOx) was immobilized on the ZnO NWs by physical adsorption. This GOx/ZnO-NWs/Au/polyester biosensor was found to exhibit fast sensing, with a sensitivity of 19.5 μA/(mM cm2). The authors reported the Au-coated polyester substrate to have specific advantages including lower cost, light weight, and flexibility and it could be a promising candidate for the large-scale commercialization of glucose oxidase biosensors. Sun et al. [89] reported synthesizing sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO3H) nanoparticles. The glucose biosensor was fabricated by immobilizing positively charged Au nanoparticles, H30-SO3H nanoparticles, and glucose oxidase (GOx) onto the surface of a glassy carbon electrode for the detection of glucose in whole blood with a wide linear range (0.2 20 mM) and a low detection limit 1.2 3 1025 M. Generally, biofouling on the electrode surface can be due to platelet, fibrin, and/or blood cell adhesion. In this case, Au/hyperbranched polyester nanoparticles exhibited an antibiofouling property so it offers a platform for wider biomedical applications

21.4.5 CAPACITIVE BIOSENSOR Other applications using polyesters include their use as a support in the fabrication of screenprinted biosensors [90 92]. Capacitive biosensors belong to the group of affinity biosensors that operate by direct binding between the biological element (receptor) and analyte. It measures the changes in thickness of the dielectric layer at the electrolyte electrode interface. Capacitive biosensors are used in wearable sensing systems and personal healthcare devices. Different textile types have their own unique properties that alter skin electrode capacitance and the performance of capacitive biosensors. Ng et al. [93] used textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile) in the development of capacitive biosensors and the performance of these sensors was evaluated. The results revealed that a high skin electrode capacitance of a biosensor results in a low floor and better signal quality.

21.5 CONCLUSION UPs can be designed to meet diverse needs as their compositions and material characteristics can be controlled. The applicability of these polymers in membrane-based reactors, fuel cells, and

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sensors have been discussed. They have great potential to replace more expensive and corrosive systems using inorganic components in environmental monitoring. Also, due to their biocompatibility, medical applications also have good prospects.

ACKNOWLEDGMENTS N. Saranya acknowledges CSIR, New Delhi for the award of Senior Research Fellowship (SRF) (09/468/0519/ 2018-EMR-I dated 16/04/2018). The authors would like to gratefully acknowledge the Board of Research in Nuclear Sciences (BRNS), Mumbai and Govt. of India for research funding under contract no. 2013/37C/47/BRNS.

REFERENCES [1] K.L. Edwards, A designers ’ guide to engineering polymer technology, Mater. Des. 19 (1998) 57 67. [2] K. Mu¨ller, E. Bugnicourt, M. Latorre, M. Jorda, Y.E. Sanz, J.M. Lagaron, et al., Review on the processing and properties of polymer nanocomposites and nanocoatings and their applications in the packaging, Autom. Sol. Energy Fields (2017). Available from: https://doi.org/10.3390/nano7040074. [3] R.J. Iredale, C. Ward, I. Hamerton, Modern advances in bismaleimide resin technology: a 21 st century perspective on the chemistry of addition polyimides, Prog. Polym. Sci. (2016). Available from: https:// doi.org/10.1016/j.progpolymsci.2016.12.002. [4] T. Yabuhara, Y. Tada, T. Kameshima, S. Nakano, Y. Nishioka, H. Takase, Flame-Retardant Resin Compositions Compring Thermoplastic Resin, Thermotropic Liquid Crystal Polymer, and HoalogenFree Phosphazen Compound, 2003. [5] R.M. Wang, S.-R. Zheng, Y.-P. Zheng, Introduction to polymer matrix composites, Polym. Matrix Compos. Technol. (2011) 1 548. Available from: https://doi.org/10.1533/9780857092229.1. [6] M. George, G.E. Kochimoolayil, J.N. Haridas, Mechanical and thermal properties of modified kaolin clay/unsaturated polyester nanocomposites, J. Appl. Polym. Sci. 43245 (2016) 1 10. Available from: https://doi.org/10.1002/app.43245. [7] P.A. Sreekumar, J. Marc, K. Joseph, G. Unnikrishnan, S. Thomas, Electrical properties of short sisal fiber reinforced polyester composites fabricated by resin transfer molding, Compos. Part A 43 (2012) 507 511. Available from: https://doi.org/10.1016/j.compositesa.2011.11.018. [8] I.A. Asimakopoulos, G.C. Psarras, L. Zoumpoulakis, Barium titanate/polyester resin nanocomposites: development, structure-properties relationship and energy storage capability, Express Polym. Lett. 8 (2014) 692 707. Available from: https://doi.org/10.3144/expresspolymlett.2014.72. [9] M.M. D´avila Jim´enez, M.P. Elizalde, M. Gonz´alez, R. Silva, Electrochemical behaviour of nickel polyester composite electrodes, Electrochim. Acta 45 (2000) 4187 4193. Available from: https:// doi.org/10.1016/S0013-4686(00)00545-4. [10] K. Kanimozhi, P. Prabunathan, V. Selvaraj, M. Alagar, Vinyl silane-functionalized rice husk ashreinforced unsaturated polyester nanocomposites, RSC Adv. 4 (2014) 18157 18163. Available from: https://doi.org/10.1039/C4RA01125B. [11] N. Li, F. Zeng, D. Qu, J. Zhang, L. Shao, Y. Bai, Synthesis and characterization of carborane-containing polyester with excellent thermal and ultrahigh char yield, J. Appl. Polym. Sci. 133 (2016). Available from: https://doi.org/10.1002/app.44202. [12] A.C. Macasaquit, C.A. Binag, Preparation of conducting polyester textile by in situ polymerization of pyrrole, Philipp. J. Sci. 139 (2010) 189 196.

REFERENCES

573

[13] V. Tunakova, J. Gregr, M. Tunak, G. Dohnal, Functional polyester fabric/polypyrrole polymer composites for electromagnetic shielding: optimization of process parameters, J. Ind. Text. 47 (2018) 686 711. Available from: https://doi.org/10.1177/1528083716667262. [14] A.A. Khan, Preparation of unsaturated polyester Ce (IV) phosphate by plastic waste bottles and its application for removal of Malachite green dye from water samples, Arab. J. Chem. 6 (2013) 361 368. Available from: https://doi.org/10.1016/j.arabjc.2010.10.012. [15] A. Tugrul Seyhan, F.H. Gojny, M. Tanoglu, K. Schulte, Critical aspects related to processing of carbon nanotube/unsaturated thermoset polyester nanocomposites, Eur. Polym. J. 43 (2007) 374 379. Available from: https://doi.org/10.1016/j.eurpolymj.2006.11.018. [16] A. Ayoub, K. chul Sun, I.A. Sahito, M.B. Qadira, S.H. Jeong, Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell fabric as textile based flexible counter electrode, Phys. Chem. Chem. Phys. (2015). Available from: https://doi.org/10.1039/ C5CP00818B. [17] K. Jost, C.R. Perez, J.K. McDonough, V. Presser, M. Heon, G. Dion, et al., Carbon coated textiles for flexible energy storage, Energy Environ. Sci. 4 (2011) 5060. Available from: https://doi.org/10.1039/ c1ee02421c. [18] S. Min, J. Han, Enhancement of electrochemical performance of textile based supercapacitor using mechanical pre-straining, J. Power Sources 244 (2013) 783 791. Available from: https://doi.org/ 10.1016/j.jpowsour.2013.02.087. [19] C. Jin, L. Jin, M. Guo, P. Liu, J. Zhang, S. Bian, MnO2 nanotubes assembled on conductive graphene/ polyester composite fabric as a three-dimensional porous textile electrode for flexible electrochemical capacitors, J. Colloid Interface Sci. 508 (2017) 426 434. Available from: https://doi.org/10.1016/j. jcis.2017.08.035. [20] M. Guo, S. Bian, F. Shao, S. Liu, Y. Peng, Hydrothermal synthesis and electrochemical performance of MnO2/graphene/polyester composite electrode materials for fl exible supercapacitors, Electrochim. Acta 209 (2016) 486 497. Available from: https://doi.org/10.1016/j.electacta.2016.05.082. [21] F. Christina, R. Ramirez, P. Ramakrishnan, Z.P. Flores-payag, Polyaniline and carbon nanotube coated pineapple-polyester blended fabric composites as electrodes for supercapacitors, Synth. Met. 230 (2017) 65 72. Available from: https://doi.org/10.1016/j.synthmet.2017.05.005. [22] J.D. Leary, E.T. Fox, B. Maze, B. Pourdeyhimi, Preparation of carbon nanotube coated nonwovens as flexible supercapacitor electrodes, J. Eng. Fiber Fabr. 11 (2016) 72 82. [23] A. Dom´enech-Carbo´, M.T. Dom´enech-Carbo´, F. Bosch-Reig, J.V. Gimeno-Adelantado, M.C. Saurı´Peris, S. S´anchez-Ramos, Electrochemistry of iron oxide pigments (earths) from pictorial microsamples attached to graphite polyester composite electrodes, Analyst 126 (2001) 1764 1772. Available from: https://doi.org/10.1039/b100257k. [24] W. Lu, H. Lin, D. Wu, G. Chen, Unsaturated polyester resin/graphite nanosheet conducting composites with a low percolation threshold, Polymer (Guildf.) 47 (2006) 4440 4444. Available from: https://doi. org/10.1016/j.polymer.2006.03.107. [25] J. Huang, D.G. Baird, J.E. McGrath, Development of fuel cell bipolar plates from graphite filled wet-lay thermoplastic composite materials, J. Power Sources 150 (2005) 110 119. Available from: https://doi. org/10.1016/j.jpowsour.2005.02.074. [26] I.A. Ioannis, J. Greenman, C. Melhuish, J. Hart, Comparative study of three types of microbial fuel cell, Enzyme Microb. Technol. 37 (2005) 238 245. Available from: https://doi.org/10.1016/j. enzmictec.2005.03.006. [27] C. Santoro, C. Arbizzani, B. Erable, I. Ieropoulos, Microbial fuel cells: from fundamentals to applications. A review, J. Power Sources 356 (2017) 225 244. Available from: https://doi.org/10.1016/j. jpowsour.2017.03.109.

574

CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

[28] D.H. Park, J.G. Zeikus, Electricity generation in microbial fuel cells using neutral red as an electronophore, Appl. Environ. Microbiol. 66 (2000) 1292 1297. [29] Evelyn, Y. Li, A. Marshall, P.A. Gostomski, Gaseous pollutant treatment and electricity generation in microbial fuel cells (MFCs) utilising redox mediators, Rev. Environ. Sci. Biotechnol. 13 (2014) 35 51. Available from: https://doi.org/10.1007/s11157-013-9322-2. [30] R.-H. Liu, G.-P. Sheng, M. Sun, G.-L. Zang, W.-W. Li, Z.-H. Tong, et al., Enhanced reductive degradation of methyl orange in a microbial fuel cell through cathode modification with redox mediators, Appl. Microbiol. Biotechnol. 89 (2011) 201 208. Available from: https://doi.org/10.1007/s00253-010-2875-x. [31] J. Jayapriya, V. Ramamurthy, Use of non-native phenazines to improve the performance of Pseudomonas aeruginosa MTCC 2474 catalysed fuel cells, Bioresour. Technol. 124 (2012) 23 28. Available from: https://doi.org/10.1016/j.biortech.2012.08.034. [32] N. Sekar, R.P. Ramasamy, Electrochemical impedance spectroscopy for microbial fuel cell characterization, J. Microb. Biochem. Technol. S6 (2013) 1 14. Available from: https://doi.org/10.4172/1948-5948. S6-004. [33] S.R. Higgins, D. Foerster, A. Cheung, C. Lau, O. Bretschger, S.D. Minteer, et al., Fabrication of macroporous chitosan scaffolds doped with carbon nanotubes and their characterization in microbial fuel cell operation, Enzyme Microb. Technol. 48 (2011) 458 465. Available from: https://doi.org/10.1016/j. enzmictec.2011.02.006. [34] M.H. Do, H.H. Ngo, W.S. Guo, Y. Liu, S.W. Chang, D.D. Nguyen, et al., Challenges in the application of microbial fuel cells to wastewater treatment and energy production: a mini review, Sci. Total Environ. 639 (2018) 910 920. Available from: https://doi.org/10.1016/j.scitotenv.2018.05.136. [35] J. Jayaprakash, A. Parthasarathy, R. Viraraghavan, Decolorization and degradation of monoazo and diazo dyes in Pseudomonas catalyzed microbial fuel cell, Environ. Prog. Sustain. Energy 35 (2016) 1623 1628. Available from: https://doi.org/10.1002/ep. [36] P. Mishra, R. Jain, Electrochemical deposition of MWCNT-MnO2/PPy nano-composite application for microbial fuel cells, Int. J. Hydrogen Energy 41 (2016) 22394 22405. Available from: https://doi.org/ 10.1016/j.ijhydene.2016.09.020. [37] S. Khilari, S. Pandit, J.L. Varanasi, D. Das, D. Pradhan, Bifunctional manganese ferrite/polyaniline hybrid as electrode material for enhanced energy recovery in microbial fuel cell, ACS Appl. Mater. Interfaces 7 (2015) 20657 20666. Available from: https://doi.org/10.1021/acsami.5b05273. [38] W. Zhang, S. Zhu, R. Luque, S. Han, L. Hu, G. Xu, Recent development of carbon electrode materials and their bioanalytical and environmental applications, Chem. Soc. Rev. (2015). Available from: https://doi.org/10.1039/C5CS00297D. [39] D.A. Lowy, L.M. Tender, J.G. Zeikus, D.H. Park, D.R. Lovley, Harvesting energy from the marine sediment water interface II, Biosens. Bioelectron. 21 (2006) 2058 2063. Available from: https://doi.org/ 10.1016/j.bios.2006.01.033. [40] S. Narayanasamy, J. Jayaprakash, Improved performance of Pseudomonas aeruginosa catalyzed MFCs with graphite/polyester composite electrodes doped with metal ions for azo dye degradation, Chem. Eng. J. 343 (2018) 258 269. Available from: https://doi.org/10.1016/j.cej.2018.02.123. [41] D.H. Park, J.G. Zeikus, Improved fuel cell and electrode designs for producing electricity from microbial degradation, Biotechnol. Bioeng. 81 (2003) 348 355. Available from: https://doi.org/10.1002/bit.10501. [42] J. Jayapriya, V. Ramamurthy, The role of electrode material in capturing power generated in Pseudomonas catalysed fuel cells, Can. J. Chem. Eng. 92 (2014) 610 614. Available from: https://doi. org/10.1002/cjce.21895. [43] J. Jayapriya, J. Gopal, V. Ramamurthy, U. Kamachi Mudali, B. Raj, Preparation and characterization of biocompatible carbon electrodes, Compos. Part B Eng. 43 (2012) 1329 1335. Available from: https:// doi.org/10.1016/j.compositesb.2011.10.019.

REFERENCES

575

[44] Y. Fan, S.-K. Han, H. Liu, Improved performance of CEA microbial fuel cells with increased reactor size, Energy Environ. Sci. 5 (2012) 8273 8280. Available from: https://doi.org/10.1039/c2ee21964f. [45] X. Xie, M. Ye, L. Hu, N. Liu, J.R. McDonough, W. Chen, et al., Carbon nanotube-coated macroporous sponge for microbial fuel cell electrodes, Energy Environ. Sci. 5 (2012) 5265. Available from: https:// doi.org/10.1039/c1ee02122b. [46] S. Pang, Y. Gao, S. Choi, Flexible and stretchable biobatteries : monolithic integration of membrane-free microbial fuel cells in a single textile layer, Adv. Energy Mater. 1702261 (2018) 1 8. Available from: https://doi.org/10.1002/aenm.201702261. [47] F. Davis, S.P.J. Higson, Biofuel cells—recent advances and applications, Biosens. Bioelectron. 22 (2007) 1224 1235. Available from: https://doi.org/10.1016/j.bios.2006.04.029. [48] L. Hu, M. Pasta, F. La Mantia, L. Cui, S. Jeong, H.D. Deshazer, et al., Stretchable, porous, and conductive energy textiles, Nano Lett. 10 (2010) 708 714. Available from: https://doi.org/10.1021/nl903949m. [49] X. Xie, M. Pasta, L. Hu, Y. Yang, J. McDonough, J. Cha, et al., Nano-structured textiles as highperformance aqueous cathodes for microbial fuel cells, Energy Environ. Sci. 4 (2011) 1293. Available from: https://doi.org/10.1039/c0ee00793e. [50] Y. Zuo, S. Cheng, D. Call, B. Logan, Tubular membrane cathode for scalable power generation in microbial fuel cells, Environ. Sci. Technol. 41 (2007) 3347 3353. Available from: https://doi.org/ 10.1021/es0627601. [51] A. Al-Mamun, W. Ahmad, M.S. Baawain, M. Khadem, B.R. Dhar, A review of microbial desalination cell technology: configurations, optimization and applications, J. Clean. Prod. 183 (2018) 458 480. Available from: https://doi.org/10.1016/j.jclepro.2018.02.054. [52] M. Rahimnejad, M. Ghasemi, G.D. Najafpour, M. Ismail, A.W. Mohammad, Synthesis, characterization and application studies of self-made Fe3O4/PES nanocomposite membranes in microbial fuel cell, Electrochim. Acta 85 (2012) 700 706. Available from: https://doi.org/10.1016/j.electacta.2011.08.036. [53] P. Choudhury, U.S. Prasad Uday, T.K. Bandyopadhyay, R.N. Ray, B. Bhunia, Performance improvement of microbial fuel cell (MFC) using suitable electrode and Bioengineered organisms: a review, Bioengineered 5979 (2017) 1 17. Available from: https://doi.org/10.1080/21655979.2016.1267883. [54] J. Jayapriya, V. Ramamurthy, Challenges to and Opportunities in Microbial Fuel Cells, Apple Academic Press, Inc., 2016. [55] K.Y. Kim, K.J. Chae, M.J. Choi, E.T. Yang, M.H. Hwang, I.S. Kim, High-quality effluent and electricity production from non-CEM based flow-through type microbial fuel cell, Chem. Eng. J. 218 (2013) 19 23. Available from: https://doi.org/10.1016/j.cej.2012.12.018. [56] R.A. Rozendal, T.H.J.A. Sleutels, H.V.M. Hamelers, C.J.N. Buisman, Effect of the type of ion exchange membrane on performance, ion transport, and pH in biocatalyzed electrolysis of wastewater, Water Sci. Technol. 57 (2008) 1757 1762. Available from: https://doi.org/10.2166/wst.2008.043. [57] G. Pasternak, J. Greenman, I. Ieropoulos, Regeneration of the power performance of cathodes affected by biofouling, Appl. Energy 173 (2016) 431 437. Available from: https://doi.org/10.1016/j. apenergy.2016.04.009. [58] G. Pasternak, J. Greenman, I. Ieropoulos, Comprehensive study on ceramic membranes for low-cost microbial fuel cells, ChemPubSoc 9 (2016) 88 96. Available from: https://doi.org/10.1002/cssc.201501320. [59] T. Kim, S. Kang, J.H. Sung, Y.K. Kang, Y.H. Kim, J.K. Jang, Characterization of polyester cloth as an alternative separator to nafion membrane in microbial fuel cells for bioelectricity generation using swine wastewater, J. Microbiol. Biotechnol. 26 (2016) 2171 2178. Available from: https://doi.org/10.4014/ jmb.1608.08040. [60] X. Zhang, S. Cheng, X. Wang, X. Huang, B.E. Logan, Separator characteristics for increasing performance of microbial fuel cells, Environ. Sci. Technol. 43 (2009) 8456 8461. Available from: https://doi. org/10.1021/es901631p.

576

CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

[61] Y. Ahn, B.E. Logan, A multi-electrode continuous flow microbial fuel cell with separator electrode assembly design, Appl. Microbiol. Biotechnol. 93 (2012) 2241 2248. Available from: https://doi.org/ 10.1007/s00253-012-3916-4. [62] S. Pandit, B.K. Nayak, D. Das, Microbial carbon capture cell using cyanobacteria for simultaneous power generation, carbon dioxide sequestration and wastewater treatment, Bioresour. Technol. 107 (2012) 97 102. Available from: https://doi.org/10.1016/j.biortech.2011.12.067. [63] Z.Z. Ismail, A.J. Jaeel, Performance of continuous flowing membrane-less microbial fuel cell with a new application of acrylic beads separator, Desalin. Water Treat. 54 (2015) 412 421. Available from: https://doi.org/10.1080/19443994.2014.885396. [64] W. He, M.J. Wallack, K.Y. Kim, X. Zhang, W. Yang, X. Zhu, et al., The effect of flow modes and electrode combinations on the performance of a multiple module microbial fuel cell installed at wastewater treatment plant, Water Res. 105 (2016) 351 360. Available from: https://doi.org/10.1016/j. watres.2016.09.008. [65] K.Y. Kim, W. Yang, P.J. Evans, B.E. Logan, Continuous treatment of high strength wastewaters using air-cathode microbial fuel cells, Bioresour. Technol. 221 (2016) 96 101. Available from: https://doi. org/10.1016/j.biortech.2016.09.031. [66] J.L. Stager, X. Zhang, B.E. Logan, Addition of acetate improves stability of power generation using microbial fuel cells treating domestic wastewater, Bioelectrochemistry 118 (2017) 154 160. Available from: https://doi.org/10.1016/j.bioelechem.2017.08.002. [67] Y. Ahn, B.E. Logan, Domestic wastewater treatment using multi-electrode continuous flow MFCs with a separator electrode assembly design, Appl. Microbiol. Biotechnol. 97 (2013) 409 416. Available from: https://doi.org/10.1007/s00253-012-4455-8. [68] Y. Ahn, M.C. Hatzell, F. Zhang, B.E. Logan, Different electrode configurations to optimize performance of multi-electrode microbial fuel cells for generating power or treating domestic wastewater, J. Power Sources 249 (2014) 440 445. Available from: https://doi.org/10.1016/j.jpowsour.2013.10.081. [69] B. Tartakovsky, S.R. Guiot, A comparison of air and hydrogen peroxide oxygenated microbial fuel cell reactors, Biotechnol. Prog. 22 (2006) 241 246. Available from: https://doi.org/10.1021/bp050225j. [70] S. Pandit, A. Sengupta, S. Kale, D. Das, Performance of electron acceptors in catholyte of a twochambered microbial fuel cell using anion exchange membrane, Bioresour. Technol. 102 (2011) 2736 2744. Available from: https://doi.org/10.1016/j.biortech.2010.11.038. [71] S. Choi, J. Rae, J. Cha, Y. Kim, G.C. Premier, C. Kim, Enhanced power production of a membrane electrode assembly microbial fuel cell (MFC) using a cost effective poly [2, 5-benzimidazole] (ABPBI) impregnated non-woven fabric filter, Bioresour. Technol. 128 (2013) 14 21. Available from: https://doi. org/10.1016/j.biortech.2012.10.013. [72] A.E.W. Horst, K.M. Mangold, D. Holtmann, Application of gas diffusion electrodes in bioelectrochemical syntheses and energy conversion, Biotechnol. Bioeng. 113 (2016) 260 267. Available from: https:// doi.org/10.1002/bit.25698. [73] L. Gil-carrera, A. Escapa, P. Mehta, G. Santoyo, S.R. Guiot, A. Mor´an, et al., Bioresource technology microbial electrolysis cell scale-up for combined wastewater treatment and hydrogen production, Bioresour. Technol. 130 (2013) 584 591. Available from: https://doi.org/10.1016/j. biortech.2012.12.062. [74] H. Yuan, Z. He, Integrating membrane filtration into bioelectrochemical systems as next generation energy-efficient wastewater treatment technologies for water reclamation: a review, Bioresour. Technol. 195 (2015) 202 209. Available from: https://doi.org/10.1016/j.biortech.2015.05.058. [75] L. Xu, G. Zhang, G. Yuan, H. Liu, J. Liu, F. Yang, Anti-fouling performance and mechanism of anthraquinone/polypyrrole composite modified membrane cathode in a novel MFC aerobic MBR coupled system, RSC Adv. 5 (2015) 22533 22543. Available from: https://doi.org/10.1039/C5RA00735F.

REFERENCES

577

[76] J. Liu, L. Liu, B. Gao, F. Yang, Integration of bio-electrochemical cell in membrane bioreactor for membrane cathode fouling reduction through electricity generation, J. Membr. Sci. 430 (2013) 196 202. Available from: https://doi.org/10.1016/j.memsci.2012.11.046. [77] K.P. Katuri, C.M. Werner, R.J. Jimenez-sandoval, W. Chen, S. Jeon, B.E. Logan, et al., Anaerobic electrochemical membrane bioreactor (AnEMBR) with conductive hollow-fiber membrane for treatment of low-organic strength solutions, Environ. Sci. Technol. 48 (2014) 12833 12841. [78] L. Malaeb, K.P. Katuri, B.E. Logan, H. Maab, S.P. Nunes, P.E. Saikaly, A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment, Environ. Sci. Technol. 47 (2013) 11821 11828. Available from: https://doi.org/10.1021/es4030113. [79] N. Li, L. Liu, F. Yang, Power generation enhanced by a polyaniline phytic acid modified filter electrode integrating microbial fuel cell with membrane bioreactor, Sep. Purif. Technol. 132 (2014) 213 217. Available from: https://doi.org/10.1016/j.seppur.2014.05.028. [80] T. Yu, L. Liu, Q. Yang, J. Song, F. Yang, Catalytic and filterable polyester-filter membrane electrode with a high performance carbon foam Fe Co catalyst improved electricity generation and waste-water treatment in MBR MFC, RSC Adv. 5 (2015) 48946 48953. Available from: https://doi.org/10.1039/C5RA05965H. [81] N. Li, L. Liu, F. Yang, Highly conductive graphene/PANi-phytic acid modified cathodic fi lter membrane and its antifouling property in EMBR in neutral conditions, Desalination 338 (2014) 10 16. Available from: https://doi.org/10.1016/j.desal.2014.01.019. [82] D. Li, M.W. Frey, A.J. Baeumner, Electrospun polylactic acid nanofiber membranes as substrates for biosensor assemblies, J. Membr. Sci. 279 (2006) 354 363. Available from: https://doi.org/10.1016/j. memsci.2005.12.036. [83] P. Ertl, M. Wagner, E. Corton, S.R. Mikkelsen, Rapid identification of viable Escherichia coli subspecies with an electrochemical screen-printed biosensor array, Biosens. Bioelectron. 18 (2003) 907 916. [84] X. Fan, W. Zhang, Z. Hu, Z. Li, Facile synthesis of RGD-conjugated unimolecular micelles based on polyester dendrimer for targeting drug delivery, J. Mater. Chem. B (2017) 1062 1072. Available from: https://doi.org/10.1039/C6TB02234K. [85] C.R.S. De Oliveira, M.A. Batistella, S.M.D.A.G.U. De Souza, A.A.U. De Souza, Development of flexible sensors using knit fabrics with conductive polyaniline coating and graphite electrodes, J. Appl. Polym. Sci. 134 (2017) 1 10. Available from: https://doi.org/10.1002/app.44785. [86] A. Tiwari, S. Aryal, S. Pilla, S. Gong, An amperometric urea biosensor based on covalently immobilized urease on an electrode made of hyperbranched polyester functionalized gold nanoparticles, Talanta 78 (2009) 1401 1407. Available from: https://doi.org/10.1016/j.talanta.2009.02.038. [87] A. Al-ahmed, P.M. Ndangili, N. Jahed, P.G.L. Baker, E.I. Iwuoha, Polyester sulphonic acid interstitial nanocomposite platform for peroxide biosensor, Sensors (Basel) 9 (2009) 9965 9976. Available from: https://doi.org/10.3390/s91209965. [88] D. Pradhan, F. Niroui, K.T. Leung, Glucose biosensor based on ZnO nanowires supported on a goldcoated polyester substrate, ACS Appl. Mater. Interfaces 2 (2010) 2409 2412. Available from: https:// doi.org/10.1021/am100413u. [89] C. Sun, X. Chen, Q. Han, M. Zhou, C. Mao, Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique, Anal. Chim. Acta 776 (2013) 17 23. Available from: https://doi.org/10.1016/j.aca.2013.03.032. [90] A. Erlenko¨tter, M. Kottbus, G.C. Chemnitius, Flexible amperometric transducers for biosensors based on a screen printed three electrode system, J. Electroanal. Chem. 481 (2000) 82 94. Available from: https://doi.org/10.1016/S0022-0728(99)00491-X. [91] S. Cinti, D. Moscone, F. Arduini, Screen-printed electrodes as versatile electrochemical sensors and biosensors, in: Proc. 2017 IEEE East-West Des. Test Symp. EWDTS 2017. (2017) 4 7. Available from: https://doi.org/10.1109/EWDTS.2017.8110130.

578

CHAPTER 21 UNSATURATED POLYESTERS IN MICROBIAL FUEL CELLS

[92] Y. Lin, F. Lu, J. Wang, Disposable carbon nanotube modified screen-printed biosensor for amperometric detection of organophosphorus pesticides and nerve agents, Electroanalysis 16 (2004) 145 149. Available from: https://doi.org/10.1002/elan.200302933. [93] C.L. Ng, M.B.I. Reaz, Characterization of textile-insulated capacitive biosensors, Sensors 17 (2017) 1 14. Available from: https://doi.org/10.3390/s17030574.

FURTHER READING B. Dholakiya, Unsaturated polyester resin for specialty applications, Polyester (2012) 167 202. Available from: https://doi.org/10.5772/48479. A.K. Kulshreshtha, C. Vasile, Handbook of Polymer Blends, Rapra Technology Limited, 2002. T.E. Long, Modern Polyesters : Chemistry and Technology of Polyesters and Copolyesters, Wiley Series in Polymer Science Series Editor, 2003. H.E.-D.M. Saleh, Polyester, InTech, 2012. Available from: http://dx.doi.org/10.5772/2748.