Nanocellulose leaf-like zeolitic imidazolate framework (ZIF-L) foams for selective capture of carbon dioxide

Accepted Manuscript Title: Nanocellulose Leaf-like Zeolitic Imidazolate Framework (ZIF-L) Foams for Selective Capture of Carbon Dioxide Authors: Luis Valencia, Hani Nasser Abdelhamid PII: DOI: Reference:

S0144-8617(19)30277-2 https://doi.org/10.1016/j.carbpol.2019.03.011 CARP 14680

To appear in: Received date: Revised date: Accepted date:

14 December 2018 25 February 2019 3 March 2019

Please cite this article as: Valencia L, Abdelhamid HN, Nanocellulose Leaf-like Zeolitic Imidazolate Framework (ZIF-L) Foams for Selective Capture of Carbon Dioxide, Carbohydrate Polymers (2019), https://doi.org/10.1016/j.carbpol.2019.03.011 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Nanocellulose Leaf-like Zeolitic Imidazolate Framework (ZIF-L) Foams for Selective Capture of Carbon Dioxide

Luis Valencia1*, and Hani Nasser Abdelhamid2* 1

IP T

Department of Materials and Environmental Chemistry, Stockholm University, Frescativägen 8, 10691, Stockholm, Sweden 2 Advanced Multifunctional Materials Laboratory, Department of Chemistry, Faculty of Science, Assiut University, Assiut, 71515, Egypt

SC R

*Corresponding author: [email protected] (L. Valencia); [email protected]; [email protected] (H.N. Abdelhamid)

A

N

U

Highlights  Synthesis of nanocellulose-ZIF-L foams at room temperature using water as solvent  Characterize nanocellulose-ZIF-L foams using wide analytical tools  Record adsorption of CO2

M

Abstract

ED

The last decades have been witness of an ever-growing interests for the synthesis and application of metal–organic frameworks (MOFs). However, most of the current synthetic

PT

procedures are limited to yield MOFs in powder state. In this work, hybrid foams were fabricated by using in situ synthesis of leaf-like zeolitic imidazolate frameworks (ZIF-L) into

CC E

nanocellulose at room temperature using water as solvent, followed by a gelatin matrix incorporation and freeze-drying. The foams are ultralight weight and are highly porous with

A

densities ranging from 19.18 to 37.4 kg·m−3. The shapeability, hierarchical porosity, and low density of the formed foams offer promising potential for applications such as CO2 sorption. The dispersion of ZIF-L into the cellulose network increases the material accessibility and may open new venues for further MOFs processing.

1

Keywords: Nanocellulose; Foams; Metal-Organic Frameworks; Zeolitic Imidazolate Frameworks; CO2 adsorption.

Introduction

IP T

Metal-organic frameworks (MOFs), are porous materials consisting of metal and

organic moieties (Yao et al., 2015; Yuan et al., 2018; Zou et al., 2016), which have

SC R

impacted the progress of several applications including CO2 reduction (Chambers et

al., 2015; Diercks et al., 2018), CO2 capture and conversion (Abdelhamid & Zou, 2018;

U

Ding & Jiang, 2018), catalysis (Emam et al., 2018; Zhang et al., 2018), adsorption

N

(Abdel-Magied et al., 2019; Li et al., 2018), sensing\biosensing (Abdelhamid et al.,

A

2017; Yang et al., 2016), drug delivery (Abdelhamid & Wu, 2019), energy-related

M

applications (Abdelhamid, 2018; Wang et al., 2018), and mass spectrometry (Abdelhamid, 2019). MOFs have unique properties such as large surface area, high

ED

porosity, tunable structure and multifunctional applications (Abdelhamid et al., 2019; Falcaro et al., 2016; Gaillac et al., 2017). MOFs are typically synthesized in the form

PT

of powders, which hampers their applications, therefore constructing materials such as

CC E

monoliths and foams have gained increasing interest (Sultan et al., 2018; Wu et al., 2017). However, it remains challenging to synthesize an easy-handling MOFs-based materials with hierarchical porosities for industrial applications and commercial

A

purposes (Abdelhamid, 2017). Biopolymers, such as nanocellulose and gelatin, are promising porous supporting materials because they are abundant, produced from renewable sources, biodegradability and inexpensive. Nanocellulose offers great versatility of surface functionalization due to their abundant surface functional groups such as hydroxyl, 2

carbonyl, carboxylic groups. It shows also outstanding mechanical properties. Nanocellulose-based foams are promising candidates for several applications (Lavoine & Bergström, 2017) including heat insulating materials (De France et al., 2017), supercapacitors (Yang et al., 2015), as absorbents (Wei et al., 2017), and flexible devices (Toivonen et al., 2015). Furthermore, nanocellulose provides a universal

IP T

substrate for the synthesis of nanoparticles such as gold nanoparticles (Eisa et al., 2018), silver nanoparticles (Han et al., 2016), silica (Demilecamps et al., 2015),

SC R

magnesium hydroxide nanoparticles (Han et al., 2015), graphene oxide (Wan & Li, 2016), and hybrid carbon nanomaterials (Zheng et al., 2015). However, very few literature examples were published for combining MOFs and nanocellulose. MOFs

U

such as zeolitic imidazolate frameworks (ZIF-90) (Matsumoto & Kitaoka, 2016), ZIF-

N

8 nanocrystals (Su et al., 2018), Universiteteti Oslo-66 (UiO-66), and Materials of

A

Institute Lavoisier-100 (MIL-100(Fe)) (Zhu et al., 2016), Hong Kong University of

M

Science and Technology-1 (HKUST-1) and ZIF-67 ( Zhu et al., 2018), were reported

ED

using cellulose as substrate. However, the current synthetic procedures require most of the times unfriendly solvents (e.g. dimethylformamide, DMF) (Matsumoto & Kitaoka,

PT

2016), high temperature (70 ℃ for 24 h)(Su et al., 2018), multisteps (H. Zhu et al., 2016), and long reaction times (Zhu et al., 2018).

CC E

Herein, we reported a one-pot synthesis of gelatin/nanocellulose-leaf-like zeolitic

imidazolate framework (ZIF-L) foams, (ZIF-L refers to Zn(mim)2·(Hmim)1/2·(H2O)3/2,

A

and Hmim refers to 2-methylimidazole). 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized cellulose nanofiber (TOCNF) was used as model for nanocelluose. In situ growth of ZIF-L into TOCNF was achieved at room temperature using water as solvent. The formed gel was incorporated into a gelatin matrix, and subjected to freezedrying to obtain ultralight weight foams with good mechanical stability. Applications

3

of the synthesized foams for selective CO2 adsorption-desorption is also reported. The formed foams offer hierarchical porous structure and is believed to enhance the diffusion of molecules for faster kinetics of adsorption and regeneration, as well as facilitate the scalability and easy processing of adsorbent materials, leading to a reduction in costs.

IP T

Experimental section Chemicals and Materials

SC R

2-methylimidazole (Hmim), triethylamine (TEA), Zn(NO3)2·6H2O, 2,2,6,6-

tetramethylpiperidine-1-oxyl radical (TEMPO), sodium bromide (NaBr), sodium chlorite (NaClO) and gelatin were purchased from Sigma-Aldrich (Germany).

U

Deionized water was used for the preparation of all solutions.

N

Fabrication of TOCNF

A

TOCNF was obtained from a defibrillation process of soft wood pulp, following the

M

reported procedures (Isogai et al., 2011). In brief, an aqueous suspension of pulp from

ED

Norwegian spruce was subjected to TEMPO-mediated an oxidation steps using TEMPO, NaClO and NaBr. The obtained carboxylated fibers (1.5 mol·g -1) were

PT

subjected to mechanical disintegration using a high-pressure homogenizer to yield fully defibrillated cellulose nanofibrils (CNF).

CC E

Fabrication of hybrid foams The in-situ growth of ZIF-L into TOCNF networks was carried out at room

A

temperature. First, TOCNF (15 g, 0.5 wt.%) was added into a 50 mL beaker. Secondly, a zinc nitrate hexahydrate (146.4 mg, 0.49 mmol) was added into the TOCNF dispersion. The dispersion was stirred for 2 min. TEA (78.2 mg, 0.8 mmol) was added followed by the addition of 2-methylimidazole (Hmim, 634.6 mg, 7.8 mmol). The molar ratios of Zn:Hmim:TEA is 1:16:1.6. After stirring vigorously for 2 min, the

4

milky mixture was left for 1 hour. ZIF-L@TOCNF sample (denoted as MF-1, MOFFoam) was separated using a filter paper, and washed with deionized water. Finally, gelatin (5 g, 4 wt. %) was added and the aqueous suspension were mixed using a highspeed disperser (Ultra-Turrax, IKA), followed by cooling at 3 °C overnight. The suspension was degassed before freeze-casting using Teflon molds sitting on a copper

IP T

plate in contact with dry ice. The cooling rate was estimated at 15 K·min -1 followed by freeze-drying.

SC R

Different loadings of reactants Zn(NO3)2·6H2O, Hmim, and TEA were also

investigated following the same procedure as described above. MF-2 was synthesized using Hmim (924.4 mg, 11.4 mmol), TEA (113.9 mg, 1.1 mmol) and zinc nitrate

U

(213.2 mg, 0.76 mmol). While, MF-3 was synthesized using Hmim (1.90 g, 23.4

N

mmol), TEA (234.7 mg, 2.3 mmol) and zinc nitrate (439.3 mg, 1.5 mmol). For all

A

cases, TOCNF (15 g, 0.5 wt.%) and gelatin (5 g, 4 wt.%) were used. Foams of TOCNF

M

with gelatin (denoted as Ref.) were also prepared as controls without ZIF-L.

ED

Characterization

Fourier transform infrared (FT-IR) was measured using attenuated total reflectance

PT

Fourier transform infrared (ATR-FTIR) (Varian 610-IR, UK) in the range of 4000–390 cm−1. Powder X-ray diffraction (XRD) patterns were recorded using a PANalytical

CC E

X’Pert PRO X-ray system with current, tension, temperature, and step size (2θ) of 40 mA, 45 kV, 25 °C and 0.05, respectively. The apparent densities of the foams were

A

calculated by weighting the samples and measuring their volumes. Nitrogen adsorption was performed using a Micromeritics ASAP 2020 instrument and samples were degassed at 100 °C for 10 h. The specific surface area were determined using the Brunauer–Emmett–Teller (BET) and Langmuir methods. The morphology of the samples was examined using scanning electron microscopy (SEM) conducted on a

5

JEOL (JSM-7000, Japan) or TEM3000 (Hitachi, Japan) at accelerated voltage of 2 or 1.8 kV. Energy dispersive X-ray (EDX) measurements were reported using the same equipment with working distance 10 mm. Atomic force microscope (AFM) was measured using Nanoscope V, Veeco Instruments (Santa Barbara, CA, USA) in tapping mode. The rheological properties of gelatin-TOCNF gels were measured on a

IP T

MRC301 rheometer (Anton Paar, Germany) at 20 °C using a sand blasted 40 mm

parallel plate geometry with a 1 mm gap for viscous samples and a 27 mm Couette

SC R

geometry. A time sweep was measured for 5 minutes, measuring G′ and G″ at 0.1%

strain and a frequency of 1 Hz. For a determination of the yield stress, a shear rate was applied ranging from 0.001 to 10 s-1 and back to 0.001 to measure the shear stress and

U

viscosity response. The Young's modulus was calculated by fitting a line through the

A

CO2 adsorption studies

M

determining the slope of these lines.

N

elastic region of the Stree-Strain response of the different hybrid foams, and

ED

CO2 adsorption-desorption was performed at 0 °C using ASAP 2020 adsorption analyzer. All the samples were evacuated to ultrahigh vacuum at 100 °C for 10 h

PT

before the measurements. The reusability and selectivity of the foams for CO 2 capture was measured using Thermogravimetric gas sorption analysis performed in a TA

CC E

Instruments Discovery thermobalance using LABLINE 5.5 CO2, 5.0 N2 gases and 5-10 mg of samples spread in 100 uL Pt pans. The CO2 sorption was measured by the

A

weight increase upon switching from N2 to CO2 atmosphere. After maximum adsorption, the gas was switched back to N2 for desorption. A flow of 100 mL/min was used for all measurements. Results and Discussions Materials Characterization

6

The general synthesis procedure of ZIF-L@TOCNF foams (MF-1, MF-2, and MF-3) is schematic represented in Fig. 1. The TOCNF exhibited a thickness of 5-10 nm, and length of 1-2 μm (Fig. S1). The method involves in situ growth of ZIF-L on TOCNF, embed the modified nanofibers in a gelatin matrix, and cool down to induce the change of conformation of gelatin to triple helix structure, followed by freeze‐drying (Fig. 1).

IP T

The proposed mechanism for the in situ growth modification of the nanofibers is

schematically represented in Fig. 2a. The interaction between TOCNF and reactants for

SC R

each step was followed using FT-IR spectroscopy (Fig. S2) and XRD (Fig. S3). FT-IR spectrum of TOCNF shows peaks at 3300, 1634, and 1055 cm-1 corresponding to O—

U

H, C=O, and O—C, respectively (Fig. S2). In the first stage, Zn2+ ions are coordinated into the functional groups of TOCNF fibers. The hydroxyl and carbonyl groups of

A

N

TOCNF become broad upon interaction with Zn2+ ions (Fig. 2a). There is no clear

M

change after the addition of TEA to the solution i.e. after formation of ZnO crystal that is confirmed using XRD pattern (Fig. S3). ZIF-L is formed after the addition of Hmim.

ED

The phase purity of the final product is confirmed using XRD patterns (Fig. 3). Data confirm the formation of leaf-like ZIF (ZIF-L) with high crystallinity (Fig. 3). There is

PT

no change in the phase purity using different concentration of zinc nitrate from 0.49 mmol (MF-1) to 1.5 mmol (MF-3) as shown in Fig. 3. The observed peak at 420 cm-1

CC E

in FT-IR spectra refers to Zn—N (Hmim, Fig. S2). The resultant ZIF-L@TOCNF suspension was then washed to remove any traces of unreacted reagents, and

A

incorporated into a gelatin matrix. ZIF-L@TOCNF interacts via electrostatic interactions with the amine groups of gelatin. The resultant materials were cooled overnight, inducing the physical thermos-reversible gelation which occurs due to the partial recovery of collagen triple-helix structure by disorder-order rearrangement (Fig. 2b).

7

M

A

N

U

SC R

IP T

Figure 1 Schematic illustration of the fabrication process of ZIF-L@TOCNF foams.

A

CC E

PT

ED

Figure 2 (a) Proposed mechanism for the in situ growth of ZIF-L on TOCNF; and (b) the network formation of gelatin/ZIF-L@TOCNF.

8

IP T SC R U N A M ED

CC E

PT

Figure 3 XRD pattern for TOCNF, MF-1, MF-2, and MF-3.

Divalent zinc ions may cause cross linking of TOCNF and change the fibres rheological properties. The Storage moduli (G´´) of the gel materials is increased with

A

adding of the reactants Zn2+, TEA, and Hmim (Fig. S4-S5). The addition of zinc salt also increases the ionic strength, and thus reducing the Debye length among the nanofibers, which also contributes to the increase in gel strength. The subsequent addition of TEA and Hmim, lead to the in situ formation of ZIF-L on TOCNF, which has abundant polar groups such as e.g. hydroxyl and carboxyl, offering copious strong 9

binding sites for nucleation, growth and adhesion of ZIF-L crystals. Upon addition of Hmim, the rheological properties of the gel were detrimentally affected, as the ZIF-L particles are believed interpose among the fibers, preventing hydrogen bonding or other interactions between them (Fig. S4-S5). The aforementioned interaction between gelatin and TOCNF was demonstrated by an increase in the Storage modulus and

IP T

viscosity (Fig. S4-S5). The resultant gels were then directionally frozen to promote ice

crystal growth, and the final foam was obtained by freeze‐drying (Fig. 4). The material

SC R

after freeze-dry were characterized using FT-IR (Fig. S6), SEM (Fig. 5, and Fig. S7), high resolution SEM (Fig. S8), EDX analysis and mapping (Fig. S9), and N 2 adsorption (Fig. 6a). FT-IR spectrum of TOCNF shows characteristic peaks at 3342,

N

U

2894, 1604, and 1016 cm-1, corresponding to bonds of O—H, C—H, C=O, and C—O, respectively (Fig. S6). The spectrum of Ref. foam (Fig. S6) containing collagen shows

A

peaks corresponding to absorption of ν(C=O) (amide I, 1,641–1,550 cm−1), δ(CH2),

M

and δ(CH3) (1,455–1,409 cm−1), ν(C–N), and δ(N–H) of amide III (1,347–1,153 cm−1),

ED

and ν(C–O) and ν(C–O–C) absorptions of carbohydrate moieties (1,051–1,024 cm−1) (Belbachir et al., 2009). Foams containing ZIF-L (MF-1, and MF-3) display extra

PT

peaks in the region of 500−1350 cm−1 and 1350−1500 cm−1 referring to the bending and stretching of the imidazolate ring, respectively (Abdelhamid et al., 2017). C=C and

CC E

C–N stretches at 1606 cm−1 and 1580 cm−1. The peak at 420 cm-1 refers to Zn—N (imidazole) confirming the presence of ZIF-L frameworks into the formed foams (Fig.

A

S6). Peak of O—H at 3300 cm-1 for TOCNF and Ref. becomes broad after formation of ZIF-L due to the interaction and the presence of water molecules in the crystal structure of ZIF-L (Zn(mim)2·(Hmim)1/2·(H2O)3/2) (Fig. S6). FT-IR spectra confirm the interactions within the foams and support the formation of ZIF-L (Fig. S6).

10

IP T SC R

A

N

U

Figure 4 (a) Overview of the microstructure of freeze-dry hybrid foams, EDX mapping of zinc in the top and edge of the foams, (b) photographs for the foam on the stigma for a flower, and c) 500 g object on the top of the hybrid foams (MF-2 was used as model).

M

SEM images of the formed foams confirm the formation of hierarchical porous structure containing mesopore, and macropore structure, which arise due to ice crystal

ED

formation. (Fig. 4-5, and Fig. S7-S8). SEM images show white particles refers to ZIFL particles that were confirmed from EDX analysis and mapping (Fig. S9). SEM cross-

PT

section image of the synthesized foams was also reported to elucidate the influence of

CC E

ZIF-L loading over the hierarchical structure of the anisotropic foams, as well as the distribution of them into the gelating-TOCNF networks (Fig. 5). The foams displayed a conventional honeycomb pore structure (Fig. 5). Data show the formation of an

A

anisotropic tubular pore structure as result of the unidirectional freeze-casting process, where the pores run parallel to the freezing direction throughout the material. Highresolution (HR)-SEM images show that ZIF-L particles are embedded into the wall of the foams (Fig. S8). HRSEM images reveals that the particle size of ZIF-L is 100-200 nm (Fig. S8). The presence of TOCNF during the crystal growth leads to a small

11

particles size. TOCNF enhances the crystal nucleation over growth, and thus decreases the size of ZIF-L crystals (Zhu et al., 2018). On the other hand, it also prevents the aggregation and improves the pore accessibility of ZIF-L particles, and thus may improve the performance of ZIF-L particles for applications including adsorption, catalysis...etc. In sharp contrast to simply blending ZIF-L crystals with cellulose

IP T

nanocrystals, in situ growth of ZIF-L is simple, controllable, and requires fewer

synthesis steps. The percentage of ZIF-L into the foam was determined using EDX

SC R

analysis. Data shows Zn content of 4.6, 8.5, and 11.0% for MF-1, MF-2, and MF-3,

corresponding to ZIF-L of 21%, 39%, and 50%, respectively. The presence of ZIF-L in the final products (MF-1, MF-2, and MF-3) increases with the increase of the

U

reactants amounts. EDX mapping shows also a uniform dispersion of ZIF-L into

N

TOCNF networks (Fig. S9). The resultant foams are ultralight weight as they can rest

A

on top of the stigma of a flower (Fig. 4b). However, they offer excellent mechanical

M

properties and can hold a mass of a 500 g object without any observable damage of the

A

CC E

PT

ED

formed foam (Fig. 4c).

12

IP T SC R U N A

ED

M

Figure 5 SEM image of a freeze-cast hybrid foams; a) Ref., b) MF-1, c) MF-2, and d) MF-3. Scale bar stands for 100 μm. The white particles refers to ZIF-L crystals.

PT

The synthesized materials resulted in the formation of extremely porous hybrid foams with large accessible surface area, and with ultralow densities as low as 37.4 kg·m -3

CC E

(Table 1), compared to the density of Ref. (without ZIF-L) which is 13.9 kg·m-3 (Table 1). The presence of ZIF-L increases the density of the foams due to the high density of ZIF-L (Table 1), increasing gradually as a function of ZIF-L loading from 19.2 kg·m-3

A

for 21% to 22.4 kg·m-3 and 37.4 kg·m-3 for 39% and 50% of ZIF-L, respectively. The porosity of the formed foams was evaluated using N2 adsorption-desorption as shown in Fig. 6a. Data shows BET and Langmuir surface area of 5-14 m2·g-1 (Fig. 6a, Table 1).

13

Table 1 Summary of the main physical properties of the hybrid aerogels.

ρ (kg·m-3)a

SBET (m2·g-1)

SLan (m2·g-1)

Pore volume (cm3·g-1)

Ref.

0

13.9

14

14

0.03

MF-1

21

19.2

5

5

0.01

MF-2

39

22.4

8

9

0.02

MF-3

50

37.4

10

12

0.02

apparent density of hybrid foams

SC R

a

IP T

Sample ZIF-L (%)

The mechanical properties of the foams were measured by compression testing, which indicates how in situ growth of ZIF-L affect the microstructure of the foams, and the

U

stress-strain curves of the hybrid foams are shown in Fig. S10. Compared to the

N

reference foam containing only gelatin-TOCNF, MF-1 exhibited a significant

A

improvement in the mechanical properties with a Young´s modulus of 2.0 MPa

M

compared to 0.96 MPa of the Ref. foam, which is probably due to an increase in the

ED

bulk density of the porous structure of the foams by the presence of small amount of ZIF-L crystals in the cell walls (Chen et al., 2013; Zhang et al., 2016). Nevertheless,

PT

MF-2 and MF-3 displayed the opposite effect, reducing the Young’s Modulus to 0.68 and 0.24 MPa, respectively; which is explained by the disruption of gelatin-TOCNF

CC E

network due to the great amount of ZIF-L crystals. Cellulose is abundant, sustainable, and lightweight polymers with several functional groups. These functional groups may shift the balance of nucleation and growth for

A

synthesizing crystals, and thus decrease the aggregation possibilities of the powder product (Zhu et al., 2018). They also enable sufficient cross-linkers in the resultant foams and off large-strain deformation. Cellulose offers also extrinsic porosities and mechanical flexibility for the resultant ZIF-L foams.

14

Applications for CO2 Sorption Application of the foams for CO2 sorption was investigated (Fig. 6b-d). Ref. foam comprising TOCNF and gelatin exhibited a significant higher CO 2 adsorption capacity compared to pure TOCNF, which is attributed to the amine groups present in gelatin. Moreover, the presence of ZIF-L clearly enhances CO2 uptakes of the formed foams

IP T

(Fig. 6b-d). ZIF-L crystals have one large zero-dimensional pore or cavity with

dimensions of 9.4 Å × 7.0 Å × 5.3 Å, thus the CO2 sorption take place via a gate

SC R

opening mechanism (Chen et al., 2013). The cushion-shaped cavities of ZIF-L ensure higher selectivity for CO2 adsorption (Chen et al., 2013). These cavities offer flexible adsorption compared to the tetrahedral structure of other ZIFs (Chen et al., 2013).

U

Thus, adsorption of all foams containing ZIF-L shows type-I isotherms (Fig. 6b). The

N

capacity of MF-3 is lower than the pure ZIF-L due to the low content of ZIF-L (only

A

50% of ZIF-L is present in MF-3). Thus, MF-3 shows adsorption of 0.75 mmol·g-1

M

compared to pure ZIF-L that shows adsorption capacity of 0.90 mmol·g-1, that matches

A

CC E

PT

adsorption capacity.

ED

previous reported value (Chen et al., 2013). ZIF-L with low loading offers good CO2

15

IP T SC R U N A

ED

M

Figure 6 (a) N2 adsorption (closed symbols)-desorption (open symbols) of foams at 77 K, CO2 adsorption (closed symbols)-desorption (open symbols) isotherms of hybrid foams at a) 298 K and c) 273 K, and d) adsorbed CO2 amount for the investigated materials, percentage above each column represents the percentage of ZIF-L in the foams. The reusability of the hybrid foams as CO2 adsorbent was tested by carrying out

PT

multiple cycles of adsorption-desorption at room temperature (Fig. 7a). Reusability of

CC E

adsorbents is of sum importance considering that for practical application; an adsorbent should not only exhibit high adsorption capacity and high selectivity but also almost provide long-term stability over the performance in multiple cycles (Fig. 7b). There is

A

insignificant decrease in the CO2 weight-gain over repeated CO2/N2 cycles, suggesting the excellent reusability of the foams as adsorbent. However, the slightly lower weights gain after the first cycle could be attributed to the fact that a part of the adsorption sites are already occupied by N2 when the gas is switched from CO2. The CO2/N2 apparent selectivity of the hybrid foams, considering the ratio of gained 16

weight% upon CO2/N2 atmosphere, multiplied by the density ratio of both gases (ρN2/ρCO2), and results are presented in Fig. 7b. The results demonstrate the high selectivity of the foams due to characteristic adsorption properties of ZIF-L attributed to the cushion-shaped cavities that ideally accommodate CO2 molecules. Thus, the selectivity significantly increases with the increase of ZIF-L content (Fig. 7b). MF-3

M

A

N

U

SC R

IP T

exhibits almost 7 times higher selectivity than MF-1.

ED

Fig. 7 a) Illustration of CO2 adsorption and desorption cycles at 100 mL/min CO2/N2 flow rate; b) CO2/N2 apparent selectivity. ZIFs are promising adsorbents for CO2 adsorption. They showed reasonable high CO2

PT

adsorption capacity preferentially over nitrogen and other gases (Chen et al., 2013). Our materials showed high CO2 adsorption capacity compared to pure MOFs materials

CC E

such as ZIF-8 (Nune et al., 2010), ZIF-25, ZIF-71, ZIF-93, ZIF-96, ZIF-97 (Morris et al., 2010) (Table 2). To the best of our knowledge, few types of hierarchically porous

A

materials containing MOFs have been reported for CO2 adsorption. Graphene-ZIF-8 hybrid aerogel (GZAn) materials were successfully prepared by a two-step reduction strategy and a layer-by-layer assembly method (Jiang et al., 2018). The materials (MOF% is 88.6%) showed CO2 adsorption capacity of 0.99 mmol·g-1 (Jiang et al., 2018). Foam consisting of MOFs (such as HKUST-1 and ZIF-8) and

17

mesoporous silica was synthesized using a layer-by-layer (LBL) method by 10 cycles of HKUST-1 thin film growth (Shekhah et al., 2012). The foam was applied for high pressure CO2 adsorption (Shekhah et al., 2012). Results showed CO2 adsorption capacity of ~0.80 mmol·g-1 (Shekhah et al., 2012). The materials consisting of TOCNF-ZIF-L offers several advantages compared to the powder ZIF-L. The

IP T

adsorption capacity of 50% ZIF-L (CO2 adsorption capacity is 0.75 mmol·g-1) in the foam is closely comparative with the pure powder ZIF-L materials (CO2 adsorption

SC R

capacity is 0.90 mmol·g-1). TOCNF and Ref. are relative weak CO2 adsorbent with an uptake capacity of 0.11 and 0.35 mmol·g-1 at 298 K and 1 bar (Fig. 6d). The

combination of TOCNF and ZIF-L improves CO2 uptake capacity of the hybrid foam

U

via synergistic effect. The hierarchical porous structure of ZIF-L@TOCNF can

N

facilitate the strong interaction of CO2 with TOCNF and ZIF-L in the micropores.

A

Furthermore, it offers fast mass transfer of CO2 into the adsorbent through mesopores

ED

hydrophilic nature of cellulose.

M

and macropores. The presence of hydrophobic materials such as ZIFs may decrease the

Table 2. Comparison of CO2 adsorption capacity for various ZIFs and MOFs. MOF%

CO2 uptake

Ref.

(mmol·g-1)a

Simple mixing of Hmim and zinc

0.45

CC E

ZIF-8

Synthesis Conditions

PT

Materials

nitrate in methanol/1% high

(Nune et al., 2010)

A

molecular weight poly(diallyldimethylammonium chloride) solution for 24 h

ZIF-25, -

Solvothermal method at 85-125

71, -93,

°C, for 12 h using DMF

~100

0.65-2.18

(Morris et al., 2010)

18

96,-97 GZAn

88.6

0.99

(Jiang et al., 2018)

~0.80

Layer-by-Layer method

1@Silica ZIF-

(Shekhah et al., 2012)

In situ synthesis, RT, 1h

50

0.62

L@TOCNF

Here

IP T

HKUST-

SC R

Notes: a, conditions are 298K and 1 bar; DMF, N,N-dimethylformamide; GrapheneZIF-8 hybrid aerogel, GZAn; RT, Room Temperature. Conclusions

U

A new and straightforward synthetic strategy was developed to prepare leaf-like

N

zeolitic imidazolate frameworks (ZIF-L)-cellulose hybrid foam at room temperature

A

using water as solvent. The method procedure is simple, fast, and environmentally

M

friendly. This method provides effective strategy for developing multi-functional foam. The produced foams are ultralight weight with good mechanical properties. They have

ED

good capacity for selective CO2 adsorption with low loading of ZIF-L (21-50%). The

and catalysis.

PT

hybrids foams are promising for several applications such as adsorption, separation,

CC E

Acknowledgments

A

We thank Prof. A. Mathew for offering us the facilities of her lab to carry these experiments. We would also thank C. Manzanares for his help. L. Valencia thanks the project MULTIMAT (H2020-MSCA-ITN-2014) for research funding. H.N. Abdelhamid thanks Assiut University and Prof. A. Geies for support. Conflicts of interest There are no conflicts to declare.

19

A

CC E

PT

ED

M

A

N

U

SC R

IP T

References Abdel-Magied, A. F., Abdelhamid, H. N., Ashour, R. M., Zou, X., & Forsberg, K. (2019). Hierarchical porous zeolitic imidazolate frameworks nanoparticles for efficient adsorption of rare-earth elements. Microporous and Mesoporous Materials, 278, 175– 184. http://doi.org/10.1016/j.micromeso.2018.11.022 Abdelhamid, H. N. (2017). Lanthanide Metal-Organic Frameworks and Hierarchical Porous Zeolitic Imidazolate Frameworks: Synthesis, Properties, and Applications. Stockholm University. Retrieved from urn:nbn:se:su:diva-146398 Abdelhamid, H. N. (2018). Nanoparticle assisted laser desorption/ionization mass spectrometry for small molecule analytes. Microchimica Acta, 185(3), 200. http://doi.org/10.1007/s00604-018-2687-8 Abdelhamid, H. N. (2019). Nanoparticles Assisted Laser Desorption/Ionization Mass Spectrometry. In Handbook of Smart Materials in Analytical Chemistry (pp. 729–755). Chichester, UK: John Wiley & Sons, Ltd. http://doi.org/10.1002/9781119422587.ch23 Abdelhamid, H. N., Bermejo-Gómez, A., Martín-Matute, B., & Zou, X. (2017). A waterstable lanthanide metal-organic framework for fluorimetric detection of ferric ions and tryptophan. Microchimica Acta, 184(9), 3363–3371. http://doi.org/10.1007/s00604-0172306-0 Abdelhamid, H. N., Huang, Z., El-Zohry, A. M., Zheng, H., & Zou, X. (2017). A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules. Inorganic Chemistry, 56(15), 9139–9146. http://doi.org/10.1021/acs.inorgchem.7b01191 Abdelhamid, H. N., Wilk-Kozubek, M., El-Zohry, A. M., Bermejo Gómez, A., Valiente, A., Martín-Matute, B., … Zou, X. (2019). Luminescence properties of a family of lanthanide metal-organic frameworks. Microporous and Mesoporous Materials, 279, 400–406. http://doi.org/10.1016/j.micromeso.2019.01.024 Abdelhamid, H. N., & Wu, H.-F. (2019). Nanoparticles Advance Drug Delivery for Cancer Cells. In R. K. Keservani & A. K. Sharma (Eds.), Nanoparticulate Drug Delivery Systems (pp. 121–150). USA: Apple Academic Press. Abdelhamid, H. N., & Zou, X. (2018). Template-free and room temperature synthesis of hierarchical porous zeolitic imidazolate framework nanoparticles and their dye and CO 2 sorption. Green Chemistry, 20(5), 1074–1084. http://doi.org/10.1039/C7GC03805D Belbachir, K., Noreen, R., Gouspillou, G., & Petibois, C. (2009). Collagen types analysis and differentiation by FTIR spectroscopy. Analytical and Bioanalytical Chemistry, 395(3), 829–837. http://doi.org/10.1007/s00216-009-3019-y Chambers, M. B., Wang, X., Elgrishi, N., Hendon, C. H., Walsh, A., Bonnefoy, J., … Fontecave, M. (2015). Photocatalytic Carbon Dioxide Reduction with Rhodium-based Catalysts in Solution and Heterogenized within Metal-Organic Frameworks. ChemSusChem, 8(4), 603–608. http://doi.org/10.1002/cssc.201403345 Chen, H. B., Chiou, B. Sen, Wang, Y. Z., & Schiraldi, D. A. (2013). Biodegradable pectin/clay aerogels. ACS Applied Materials and Interfaces, 5(5), 1715–1721. http://doi.org/10.1021/am3028603 Chen, R., Yao, J., Gu, Q., Smeets, S., Baerlocher, C., Gu, H., … Wang, H. (2013). A twodimensional zeolitic imidazolate framework with a cushion-shaped cavity for CO2 adsorption. Chemical Communications, 49(82), 9500–2. http://doi.org/10.1039/c3cc44342f De France, K. J., Hoare, T., & Cranston, E. D. (2017). Review of Hydrogels and Aerogels Containing Nanocellulose. Chemistry of Materials, 29(11), 4609–4631. http://doi.org/10.1021/acs.chemmater.7b00531 Demilecamps, A., Beauger, C., Hildenbrand, C., Rigacci, A., & Budtova, T. (2015). 20

A

CC E

PT

ED

M

A

N

U

SC R

IP T

Cellulose–silica aerogels. Carbohydrate Polymers, 122, 293–300. http://doi.org/10.1016/j.carbpol.2015.01.022 Diercks, C. S., Liu, Y., Cordova, K. E., & Yaghi, O. M. (2018). The role of reticular chemistry in the design of CO2 reduction catalysts. Nature Materials, 17(4), 301–307. http://doi.org/10.1038/s41563-018-0033-5 Ding, M., & Jiang, H.-L. (2018). Incorporation of Imidazolium-Based Poly(ionic liquid)s into a Metal–Organic Framework for CO2 Capture and Conversion. ACS Catalysis, 8(4), 3194–3201. http://doi.org/10.1021/acscatal.7b03404 Eisa, W. H., Abdelgawad, A. M., & Rojas, O. J. (2018). Solid-State Synthesis of Metal Nanoparticles Supported on Cellulose Nanocrystals and Their Catalytic Activity. ACS Sustainable Chemistry & Engineering, 6(3), 3974–3983. http://doi.org/10.1021/acssuschemeng.7b04333 Emam, H. E., Abdelhamid, H. N., & Abdelhameed, R. M. (2018). Self-cleaned photoluminescent viscose fabric incorporated lanthanide-organic framework (Ln-MOF). Dyes and Pigments, 159, 491–498. http://doi.org/10.1016/j.dyepig.2018.07.026 Falcaro, P., Okada, K., Hara, T., Ikigaki, K., Tokudome, Y., Thornton, A. W., … Takahashi, M. (2016). Centimetre-scale micropore alignment in oriented polycrystalline metal– organic framework films via heteroepitaxial growth. Nature Materials. http://doi.org/10.1038/nmat4815 Gaillac, R., Pullumbi, P., Beyer, K. A., Chapman, K. W., Keen, D. A., Bennett, T. D., & Coudert, F.-X. (2017). Liquid metal–organic frameworks. Nature Materials, 16(11), 1149–1154. http://doi.org/10.1038/nmat4998 Han, Y., Wu, X., Zhang, X., Zhou, Z., & Lu, C. (2016). Reductant-Free Synthesis of Silver Nanoparticles-Doped Cellulose Microgels for Catalyzing and Product Separation. ACS Sustainable Chemistry & Engineering, 4(12), 6322–6331. http://doi.org/10.1021/acssuschemeng.6b00889 Han, Y., Zhang, X., Wu, X., & Lu, C. (2015). Flame Retardant, Heat Insulating Cellulose Aerogels from Waste Cotton Fabrics by in Situ Formation of Magnesium Hydroxide Nanoparticles in Cellulose Gel Nanostructures. ACS Sustainable Chemistry & Engineering, 3(8), 1853–1859. http://doi.org/10.1021/acssuschemeng.5b00438 Isogai, A., Saito, T., & Fukuzumi, H. (2011). TEMPO-oxidized cellulose nanofibers. Nanoscale, 3(1), 71–85. http://doi.org/10.1039/c0nr00583e Jiang, M., Li, H., Zhou, L., Xing, R., & Zhang, J. (2018). Hierarchically Porous Graphene/ZIF-8 Hybrid Aerogel: Preparation, CO 2 Uptake Capacity, and Mechanical Property. ACS Applied Materials & Interfaces, 10(1), 827–834. http://doi.org/10.1021/acsami.7b17728 Lavoine, N., & Bergström, L. (2017). Nanocellulose-based foams and aerogels: processing, properties, and applications. Journal of Materials Chemistry A, 5(31), 16105–16117. http://doi.org/10.1039/C7TA02807E Li, J., Wang, X., Zhao, G., Chen, C., Chai, Z., Alsaedi, A., … Wang, X. (2018). Metal– organic framework-based materials: superior adsorbents for the capture of toxic and radioactive metal ions. Chemical Society Reviews, 47(7), 2322–2356. http://doi.org/10.1039/C7CS00543A Matsumoto, M., & Kitaoka, T. (2016). Ultraselective Gas Separation by Nanoporous Metal−Organic Frameworks Embedded in Gas-Barrier Nanocellulose Films. Advanced Materials, 28(9), 1765–1769. http://doi.org/10.1002/adma.201504784 Morris, W., Leung, B., Furukawa, H., Yaghi, O. K., He, N., Hayashi, H., … Yaghi, O. M. (2010). A Combined Experimental−Computational Investigation of Carbon Dioxide Capture in a Series of Isoreticular Zeolitic Imidazolate Frameworks. Journal of the American Chemical Society, 132(32), 11006–11008. http://doi.org/10.1021/ja104035j 21

A

CC E

PT

ED

M

A

N

U

SC R

IP T

Nune, S. K., Thallapally, P. K., Dohnalkova, A., Wang, C., Liu, J., & Exarhos, G. J. (2010). Synthesis and properties of nano zeolitic imidazolate frameworks. Chemical Communications, 46(27), 4878. http://doi.org/10.1039/c002088e Shekhah, O., Fu, L., Sougrat, R., Belmabkhout, Y., Cairns, A. J., Giannelis, E. P., & Eddaoudi, M. (2012). Successful implementation of the stepwise layer-by-layer growth of MOF thin films on confined surfaces: mesoporous silica foam as a first case study. Chemical Communications, 48(93), 11434. http://doi.org/10.1039/c2cc36233c Su, Z., Zhang, M., Lu, Z., Song, S., Zhao, Y., & Hao, Y. (2018). Functionalization of cellulose fiber by in situ growth of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals for preparing a cellulose-based air filter with gas adsorption ability. Cellulose, 25(3), 1997–2008. http://doi.org/10.1007/s10570-018-1696-4 Sultan, S., Abdelhamid, H. N., Zou, X., & Mathew, A. P. (2018). CelloMOF: Nanocellulose Enabled 3D Printing of Metal-Organic Frameworks. Advanced Functional Materials, 1805372. http://doi.org/10.1002/adfm.201805372 Toivonen, M. S., Kaskela, A., Rojas, O. J., Kauppinen, E. I., & Ikkala, O. (2015). AmbientDried Cellulose Nanofibril Aerogel Membranes with High Tensile Strength and Their Use for Aerosol Collection and Templates for Transparent, Flexible Devices. Advanced Functional Materials, 25(42), 6618–6626. http://doi.org/10.1002/adfm.201502566 Wan, C., & Li, J. (2016). Graphene oxide/cellulose aerogels nanocomposite: Preparation, pyrolysis, and application for electromagnetic interference shielding. Carbohydrate Polymers, 150, 172–179. http://doi.org/10.1016/j.carbpol.2016.05.051 Wang, S., Kitao, T., Guillou, N., Wahiduzzaman, M., Martineau-Corcos, C., Nouar, F., … Serre, C. (2018). A phase transformable ultrastable titanium-carboxylate framework for photoconduction. Nature Communications, 9(1), 1660. http://doi.org/10.1038/s41467018-04034-w Wei, X., Huang, T., Yang, J., Zhang, N., Wang, Y., & Zhou, Z. (2017). Green synthesis of hybrid graphene oxide/microcrystalline cellulose aerogels and their use as superabsorbents. Journal of Hazardous Materials, 335, 28–38. http://doi.org/10.1016/j.jhazmat.2017.04.030 Wu, H. Bin, Wen, X., & Lou, D. (2017). Metal-organic frameworks and their derived materials for electrochemical energy storage and conversion : Promises and challenges, (December), 1–17. Yang, X., Shi, K., Zhitomirsky, I., & Cranston, E. D. (2015). Cellulose Nanocrystal Aerogels as Universal 3D Lightweight Substrates for Supercapacitor Materials. Advanced Materials, 27(40), 6104–6109. http://doi.org/10.1002/adma.201502284 Yang, Y., Shen, K., Lin, J., Zhou, Y., Liu, Q., Hang, C., … Chen, H. (2016). A Zn-MOF constructed from electron-rich π-conjugated ligands with an interpenetrated graphenelike net as an efficient nitroaromatic sensor. RSC Advances, 6(51), 45475–45481. http://doi.org/10.1039/C6RA00524A Yao, Q., Bermejo Gómez, A., Su, J., Pascanu, V., Yun, Y., Zheng, H., … Zou, X. (2015). Series of Highly Stable Isoreticular Lanthanide Metal–Organic Frameworks with Expanding Pore Size and Tunable Luminescent Properties. Chemistry of Materials, 27(15), 5332–5339. http://doi.org/10.1021/acs.chemmater.5b01711 Yuan, S., Qin, J.-S., Li, J., Huang, L., Feng, L., Fang, Y., … Zhou, H.-C. (2018). Retrosynthesis of multi-component metal−organic frameworks. Nature Communications, 9(1), 808. http://doi.org/10.1038/s41467-018-03102-5 Zhang, X., Huang, Z., Ferrandon, M., Yang, D., Robison, L., Li, P., … Farha, O. K. (2018). Catalytic chemoselective functionalization of methane in a metal−organic framework. Nature Catalysis, 1(5), 356–362. http://doi.org/10.1038/s41929-018-0069-6 Zhang, X., Wang, Y., Zhao, J., Xiao, M., Zhang, W., & Lu, C. (2016). Mechanically Strong 22

A

CC E

PT

ED

M

A

N

U

SC R

IP T

and Thermally Responsive Cellulose Nano fi bers/Poly( N ‑ isopropylacrylamide) Composite Aerogels. http://doi.org/10.1021/acssuschemeng.6b00814 Zheng, Q., Cai, Z., Ma, Z., & Gong, S. (2015). Cellulose Nanofibril/Reduced Graphene Oxide/Carbon Nanotube Hybrid Aerogels for Highly Flexible and All-Solid-State Supercapacitors. ACS Applied Materials & Interfaces, 7(5), 3263–3271. http://doi.org/10.1021/am507999s Zhu, H., Yang, X., Cranston, E. D., & Zhu, S. (2016). Flexible and Porous Nanocellulose Aerogels with High Loadings of Metal-Organic-Framework Particles for Separations Applications. Advanced Materials, 28(35), 7652–7657. http://doi.org/10.1002/adma.201601351 Zhu, L., Zong, L., Wu, X., Li, M., Wang, H., You, J., & Li, C. (2018). Shapeable Fibrous Aerogels of Metal–Organic-Frameworks Templated with Nanocellulose for Rapid and Large-Capacity Adsorption. ACS Nano, 12(5), 4462–4468. http://doi.org/10.1021/acsnano.8b00566 Zou, X., Yao, Q., Gómez, A. B., Su, J., Pascanu, V., Yun, Y., … Martín-Matute, B. (2016). A series of highly stable isoreticular lanthanide metal-organic frameworks with tunable luminescence properties solved by rotation electron diffraction and X-ray diffraction. Acta Crystallographica Section A Foundations and Advances, 72(a1), s136–s136. http://doi.org/10.1107/S2053273316097977

23