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Sonochemical preparation of palygorskite nanoparticles
Applied Clay Science 51 (2011) 51–53
Contents lists available at ScienceDirect
Applied Clay Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c l a y
Sonochemical preparation of palygorskite nanoparticles Zahra Darvishi, Ali Morsali ⁎ Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, P.O. Box 14155-4838, Tehran, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 15 March 2010 Received in revised form 28 October 2010 Accepted 29 October 2010 Available online 18 November 2010
a b s t r a c t Palygorskite nanoparticles were prepared by sonochemical reaction. The products were characterized by X-ray fluorescence analysis (XRF), X-ray powder diffraction (XRD), thermal gravimetry analysis (TGA), differential thermal analysis (DTA) and infrared spectroscopy. The morphology and size of the nanorods were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). © 2010 Elsevier B.V. All rights reserved.
Keywords: Sonochemistry X-ray diffraction Attapulgite Electron microscopy Palygorskite
1. Introduction Palygorskite, formerly called attapulguite, is characterized by a microfibrous morphology, high surface charge, and large specific surface area, and pronounced adsorption properties (Beall, and Goss, 2004; Brigatti, et al., 2006; Droy and Tateo, 2006; Pan et al., 2006). Although palygorskite is widely used in drilling muds, paints, liquid detergents, adhesives, car polish, cosmetics, carriers for fertilizers and pet feed, etc. (Carmody, et al., 2007; Hu, et al., 2006; Pennino, et al., 1981; Zhao and Vance, 1998; Zhu, et al., 1998), there are only a few reports about its use in nano-scale size (Cabedo et al., 2004; Guan et al., 2005; Saujanya, et al. 2002; Veli and Alyüz, 2007). We developed a simple sonochemical (Alavi and Morsali, 2010) method to prepare palygorskite nanoparticles. 2. Experimental The palygorskite sample was obtained from Merck. Different amounts (Table 1) of palygorskite were dispersed in ethanol. This dispersion was sonicated with different powers for 30 min, 1 h, 2 h, and 4 h with a high density ultrasonic probe immersed directly into the dispersion (Table 1). The obtained powders were characterized by XRD, TGA/DTA, IR spectroscopy, BET, SEM and TEM. Some samples were calcinated at 800 °C for 4 h. At all conditions the consequences of changing the sonochemical parameters were marginal. However, different particle sizes were obtained. A multiwave ultrasonic
⁎ Corresponding author. Tel.: + 98 2182884416; fax: + 98 2188009730. E-mail address: [email protected] (A. Morsali). 0169-1317/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.clay.2010.10.032
generator (Sonicator_3000; Misonix, Inc., Farmingdale, NY, USA), equipped with a converter/transducer and titanium oscillator (horn), 12.5 mm in diameter, operating at 20 kHz with a maximum power output of 600 W, was used for the ultrasonic irradiation. X-ray powder diffraction (XRD) measurements were performed with an X'pert diffractometer of Philips Company with monochromated Cukα radiation. TGA and DTA curves were recorded using a PL-STA 1500 device manufactured by Thermal Sciences. IR spectra were recorded on a SHIMADZU-IR460 spectrometer in a KBr matrix. The samples were characterized with a scanning electron microscope (SEM) (Philips XL 30) with gold coating and a transmission electron microscope (TEM) [Zeiss CEM 902 A]. 3. Results and discussion Fig. 1 shows the powder XRD patterns of palygorskite nanoparticles prepared by the sonochemical process (bottom) and bulk palygorskite (middle). The patterns showed reflections at 2θ = 8.14, 13.74, 16.34, 19.76, 27.59, 34.33, 41.99, 30.94 indicating monoclinic symmetry with the C2/m space group (Bradley, 1940). The SEM images of the bulk palygorskite and of the nanoparticles of the sample 2 (Table 1) are shown in Fig. 2. The particle size histogram of the nanoparticles (Fig. 2b,c) showed that the particle size ranged from 10 to 40 nm. The smallest particles were obtained for sample 2 (Table 1). The TEM (Fig. 3) showed that the particles were rod-shaped and were dispersed in water. The IR spectra of palygorskite (Fig. 4a) and palygorskite nanoparticles (Fig. 4b) did not reveal changes in the absorption bands. The relatively weak IR absorption bands around 3600–3300 cm−1 were attributed to the O–H stretching vibration in the attapulgite structure.
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Z. Darvishi, A. Morsali / Applied Clay Science 51 (2011) 51–53
Table 1 Experimental conditions for the preparation of palygorskite nanoparticles. Sample
Time (h)
Solvent (mL)
Palygorskite (g)
1 2 3 4 5 6 7
2 4 6 8 4 4 4
50 50 50 50 50 50 50
0.1 0.1 0.1 0.1 0.04 0.08 0.12
The sharp absorption band at 1035 cm−1 corresponded to the stretching vibration of the Si–O bond. The bands at 471–526 cm−1 were due to a Si–O bending vibration, and the band at 800 cm− 1 may correspond to the stretching vibration of Al–O–Si (Frost, et al. 1998). The band at 1031 cm−1 was attributed to the asymmetric stretching modes of Si–O–Si. The OH bending band appears at 985 cm−1 (Frost, et al. 1998). The TGA curves (Fig. 5) show a mass loss of 4% between 31 to 92 °C which was due to the removal of the physically adsorbed water molecules in attapulgite. Also TGA curves show another mass loss of 5% was observed between 100 to 600 °C which is due to the removal of chemisorbed water, and dehydroxylation of the pillars in palygorskite. The structure collapse continues up to 800 °C. The curve for nanoparticles after calcination showed only a broad exothermic effect at 300 °C. In the XRD pattern (Fig. 1, top) of the nanoparticles calcinated at 800 °C for 4 h showed the reflection at 2θ = 8.14 was absent and the lattice parameters were a = 4.8092 Å, c = 16.020 Å and z = 3. The pattern matched the standard pattern of rhombohedral dolomite. In the IR spectrum after calcination the bands at 3600–3300 and 1650 cm−1 were absent. The SEM image of the dolomite nanoparticles are seen in Fig. 6. Calcination caused complete decomposition and break up of the compound accompanied by changes of the morphology (Fig. 6). Fig. 2. SEM photographs of a) palygorskite, b) palygorskite nanoparticles (sample 2) and c) the particle size histogram of the nanoparticles.
4. Conclusion The described method for preparing palygorskite nanoparticles can potentially be used on at industrial scale, because it does not need special conditions, such as high temperature, special surfactants, long times or high temperature and pressure controlling.
Fig. 1. The XRD pattern of palygorskite nanoparticles (bottom), palygorskite (middle) and dolomite obtained by calcination of the nanoparticles at 800 °C (top).
Acknowledgement Pars Oil and Gas Company is gratefully acknowledged for supporting this investigation.
Fig. 3. TEM image of palygorskite nanoparticles.
Z. Darvishi, A. Morsali / Applied Clay Science 51 (2011) 51–53
53
References
Fig. 4. IR spectrum of a) palygorskite nanoparticles (sample 2), b) palygorskite, and c) dolomite nanoparticles.
Fig. 5. TGA diagrams of a) palygorskite and b) palygorskite nanoparticles (sample 2).
Fig. 6. SEM photograph of dolomite nanoparticles.
Alavi, M.A., Morsali, A., 2010. Syntheses and characterization of Sr(OH)2 and SrCO3 nanostructures by ultrasonic method. Ultrason. Sonochem. 17, 132–138. Beall, G.W., Goss, M., 2004. Self-assembly of organic molecules on ontmorillonite. Appl. Clay Sci. 27, 179–186. Bradley, W.F., 1940. The structural scheme of attapulgite. Amer. Min. 25, 405–410. Brigatti, M.F., Galan, E., Theng, B.K.G., 2006. Structures and mineralogy of clay minerals. In: Bergaya, F., Theng, B.K.G., Lagaly, G. (Eds.), Handbook of Clay Science: Developments in Clay Science, vol. 1. Elsevier, Amsterdam, pp. 19–86. Cabedo, L., Gime'nez, E., Lagaron, J.M., Gavara, R., Saura, J.J., 2004. Development of EVOH-kaolinite nanocomposites. Polymer. 45, 5233–5238. Carmody, O., Frost, R., Xi, Y., Kokot, S., 2007. Adsorption of hydrocarbons on organo-clays— implications for oil spill remediation. J Coll. Interf. Sci. 305, 17–19. Droy Lefaix, M.T., Tateo, F., 2006. Clays and clay minerals as drugs. In: Bergaya, F., Theng, B.K.G., Lagaly, G. (Eds.), Handbook of Clay Science: Developments in Clay Science, vol. 1, pp. 743–752. Chapter 11.6. Frost, R.L., Cash, G.A., Kloprogge, J.T., 1998. ‘Rocky Mountain leather’, sepiolite and attapulgite — an infrared emission spectroscopic study. Vibrat. Spectrosc. 16, 173–184. Guan, G., Li, C., Zhang, D., 2005. Spinning and properties of poly(ethylene terephthalate)/ organomontmorillonite nanocomposite fibers. J. Appl. Polym. Sci. 95, 1443–1447. Hu, Q.H., Qiao, S.Z., Haghseresht, F., Wilson, M.A., Lu, G.Q., 2006. Adsorption study for removal of basic red dye using bentonite. Ind. Eng. Chem. Res. 45 (2), 733–738. Pan, B., Yue, Q., Ren, J., Wang, H., Jian, L., Zhang, J., Yang, Sh., 2006. A study on attapulgite reinforced PA6 composites. Polym. Test. 25, 384–391. Pennino, U.D., Mazzoga, E., Valari, S., Alietti, A., Brigatti, M.F., Poppi, L., 1981. Interlayer water and swelling properties of monoinic montmorillonites. J. Colloid Interf. Sci 84, 301–309. Saujanya, C., Imai, Y., Tateyama, H., 2002. Structure and thermal properties of compatibilized PET/expandable fluorine mica nanocomposites. Polym. Bull. 49, 69–76. Veli, S., Alyüz, B., 2007. Adsorption of copper and zinc from aqueous solutions by using natural clay. J. Hazard. Mater. 149, 226–233. Zhao, H., Vance, G.F., 1998. Sorption of trichloroethylene by organo-clays in the presence of humic substances. Water Res. 32, 3710–3716. Zhu, L., Ren, X., Yu, S., 1998. Use of cetyltrimethylammonium bromide–bentonite to remove organic contaminants of varying polar character from water. Environ. Sci. Technol. 32, 3374.
Contents lists available at ScienceDirect
Applied Clay Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c l a y
Sonochemical preparation of palygorskite nanoparticles Zahra Darvishi, Ali Morsali ⁎ Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, P.O. Box 14155-4838, Tehran, Islamic Republic of Iran
a r t i c l e
i n f o
Article history: Received 15 March 2010 Received in revised form 28 October 2010 Accepted 29 October 2010 Available online 18 November 2010
a b s t r a c t Palygorskite nanoparticles were prepared by sonochemical reaction. The products were characterized by X-ray fluorescence analysis (XRF), X-ray powder diffraction (XRD), thermal gravimetry analysis (TGA), differential thermal analysis (DTA) and infrared spectroscopy. The morphology and size of the nanorods were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). © 2010 Elsevier B.V. All rights reserved.
Keywords: Sonochemistry X-ray diffraction Attapulgite Electron microscopy Palygorskite
1. Introduction Palygorskite, formerly called attapulguite, is characterized by a microfibrous morphology, high surface charge, and large specific surface area, and pronounced adsorption properties (Beall, and Goss, 2004; Brigatti, et al., 2006; Droy and Tateo, 2006; Pan et al., 2006). Although palygorskite is widely used in drilling muds, paints, liquid detergents, adhesives, car polish, cosmetics, carriers for fertilizers and pet feed, etc. (Carmody, et al., 2007; Hu, et al., 2006; Pennino, et al., 1981; Zhao and Vance, 1998; Zhu, et al., 1998), there are only a few reports about its use in nano-scale size (Cabedo et al., 2004; Guan et al., 2005; Saujanya, et al. 2002; Veli and Alyüz, 2007). We developed a simple sonochemical (Alavi and Morsali, 2010) method to prepare palygorskite nanoparticles. 2. Experimental The palygorskite sample was obtained from Merck. Different amounts (Table 1) of palygorskite were dispersed in ethanol. This dispersion was sonicated with different powers for 30 min, 1 h, 2 h, and 4 h with a high density ultrasonic probe immersed directly into the dispersion (Table 1). The obtained powders were characterized by XRD, TGA/DTA, IR spectroscopy, BET, SEM and TEM. Some samples were calcinated at 800 °C for 4 h. At all conditions the consequences of changing the sonochemical parameters were marginal. However, different particle sizes were obtained. A multiwave ultrasonic
⁎ Corresponding author. Tel.: + 98 2182884416; fax: + 98 2188009730. E-mail address: [email protected] (A. Morsali). 0169-1317/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.clay.2010.10.032
generator (Sonicator_3000; Misonix, Inc., Farmingdale, NY, USA), equipped with a converter/transducer and titanium oscillator (horn), 12.5 mm in diameter, operating at 20 kHz with a maximum power output of 600 W, was used for the ultrasonic irradiation. X-ray powder diffraction (XRD) measurements were performed with an X'pert diffractometer of Philips Company with monochromated Cukα radiation. TGA and DTA curves were recorded using a PL-STA 1500 device manufactured by Thermal Sciences. IR spectra were recorded on a SHIMADZU-IR460 spectrometer in a KBr matrix. The samples were characterized with a scanning electron microscope (SEM) (Philips XL 30) with gold coating and a transmission electron microscope (TEM) [Zeiss CEM 902 A]. 3. Results and discussion Fig. 1 shows the powder XRD patterns of palygorskite nanoparticles prepared by the sonochemical process (bottom) and bulk palygorskite (middle). The patterns showed reflections at 2θ = 8.14, 13.74, 16.34, 19.76, 27.59, 34.33, 41.99, 30.94 indicating monoclinic symmetry with the C2/m space group (Bradley, 1940). The SEM images of the bulk palygorskite and of the nanoparticles of the sample 2 (Table 1) are shown in Fig. 2. The particle size histogram of the nanoparticles (Fig. 2b,c) showed that the particle size ranged from 10 to 40 nm. The smallest particles were obtained for sample 2 (Table 1). The TEM (Fig. 3) showed that the particles were rod-shaped and were dispersed in water. The IR spectra of palygorskite (Fig. 4a) and palygorskite nanoparticles (Fig. 4b) did not reveal changes in the absorption bands. The relatively weak IR absorption bands around 3600–3300 cm−1 were attributed to the O–H stretching vibration in the attapulgite structure.
52
Z. Darvishi, A. Morsali / Applied Clay Science 51 (2011) 51–53
Table 1 Experimental conditions for the preparation of palygorskite nanoparticles. Sample
Time (h)
Solvent (mL)
Palygorskite (g)
1 2 3 4 5 6 7
2 4 6 8 4 4 4
50 50 50 50 50 50 50
0.1 0.1 0.1 0.1 0.04 0.08 0.12
The sharp absorption band at 1035 cm−1 corresponded to the stretching vibration of the Si–O bond. The bands at 471–526 cm−1 were due to a Si–O bending vibration, and the band at 800 cm− 1 may correspond to the stretching vibration of Al–O–Si (Frost, et al. 1998). The band at 1031 cm−1 was attributed to the asymmetric stretching modes of Si–O–Si. The OH bending band appears at 985 cm−1 (Frost, et al. 1998). The TGA curves (Fig. 5) show a mass loss of 4% between 31 to 92 °C which was due to the removal of the physically adsorbed water molecules in attapulgite. Also TGA curves show another mass loss of 5% was observed between 100 to 600 °C which is due to the removal of chemisorbed water, and dehydroxylation of the pillars in palygorskite. The structure collapse continues up to 800 °C. The curve for nanoparticles after calcination showed only a broad exothermic effect at 300 °C. In the XRD pattern (Fig. 1, top) of the nanoparticles calcinated at 800 °C for 4 h showed the reflection at 2θ = 8.14 was absent and the lattice parameters were a = 4.8092 Å, c = 16.020 Å and z = 3. The pattern matched the standard pattern of rhombohedral dolomite. In the IR spectrum after calcination the bands at 3600–3300 and 1650 cm−1 were absent. The SEM image of the dolomite nanoparticles are seen in Fig. 6. Calcination caused complete decomposition and break up of the compound accompanied by changes of the morphology (Fig. 6). Fig. 2. SEM photographs of a) palygorskite, b) palygorskite nanoparticles (sample 2) and c) the particle size histogram of the nanoparticles.
4. Conclusion The described method for preparing palygorskite nanoparticles can potentially be used on at industrial scale, because it does not need special conditions, such as high temperature, special surfactants, long times or high temperature and pressure controlling.
Fig. 1. The XRD pattern of palygorskite nanoparticles (bottom), palygorskite (middle) and dolomite obtained by calcination of the nanoparticles at 800 °C (top).
Acknowledgement Pars Oil and Gas Company is gratefully acknowledged for supporting this investigation.
Fig. 3. TEM image of palygorskite nanoparticles.
Z. Darvishi, A. Morsali / Applied Clay Science 51 (2011) 51–53
53
References
Fig. 4. IR spectrum of a) palygorskite nanoparticles (sample 2), b) palygorskite, and c) dolomite nanoparticles.
Fig. 5. TGA diagrams of a) palygorskite and b) palygorskite nanoparticles (sample 2).
Fig. 6. SEM photograph of dolomite nanoparticles.
Alavi, M.A., Morsali, A., 2010. Syntheses and characterization of Sr(OH)2 and SrCO3 nanostructures by ultrasonic method. Ultrason. Sonochem. 17, 132–138. Beall, G.W., Goss, M., 2004. Self-assembly of organic molecules on ontmorillonite. Appl. Clay Sci. 27, 179–186. Bradley, W.F., 1940. The structural scheme of attapulgite. Amer. Min. 25, 405–410. Brigatti, M.F., Galan, E., Theng, B.K.G., 2006. Structures and mineralogy of clay minerals. In: Bergaya, F., Theng, B.K.G., Lagaly, G. (Eds.), Handbook of Clay Science: Developments in Clay Science, vol. 1. Elsevier, Amsterdam, pp. 19–86. Cabedo, L., Gime'nez, E., Lagaron, J.M., Gavara, R., Saura, J.J., 2004. Development of EVOH-kaolinite nanocomposites. Polymer. 45, 5233–5238. Carmody, O., Frost, R., Xi, Y., Kokot, S., 2007. Adsorption of hydrocarbons on organo-clays— implications for oil spill remediation. J Coll. Interf. Sci. 305, 17–19. Droy Lefaix, M.T., Tateo, F., 2006. Clays and clay minerals as drugs. In: Bergaya, F., Theng, B.K.G., Lagaly, G. (Eds.), Handbook of Clay Science: Developments in Clay Science, vol. 1, pp. 743–752. Chapter 11.6. Frost, R.L., Cash, G.A., Kloprogge, J.T., 1998. ‘Rocky Mountain leather’, sepiolite and attapulgite — an infrared emission spectroscopic study. Vibrat. Spectrosc. 16, 173–184. Guan, G., Li, C., Zhang, D., 2005. Spinning and properties of poly(ethylene terephthalate)/ organomontmorillonite nanocomposite fibers. J. Appl. Polym. Sci. 95, 1443–1447. Hu, Q.H., Qiao, S.Z., Haghseresht, F., Wilson, M.A., Lu, G.Q., 2006. Adsorption study for removal of basic red dye using bentonite. Ind. Eng. Chem. Res. 45 (2), 733–738. Pan, B., Yue, Q., Ren, J., Wang, H., Jian, L., Zhang, J., Yang, Sh., 2006. A study on attapulgite reinforced PA6 composites. Polym. Test. 25, 384–391. Pennino, U.D., Mazzoga, E., Valari, S., Alietti, A., Brigatti, M.F., Poppi, L., 1981. Interlayer water and swelling properties of monoinic montmorillonites. J. Colloid Interf. Sci 84, 301–309. Saujanya, C., Imai, Y., Tateyama, H., 2002. Structure and thermal properties of compatibilized PET/expandable fluorine mica nanocomposites. Polym. Bull. 49, 69–76. Veli, S., Alyüz, B., 2007. Adsorption of copper and zinc from aqueous solutions by using natural clay. J. Hazard. Mater. 149, 226–233. Zhao, H., Vance, G.F., 1998. Sorption of trichloroethylene by organo-clays in the presence of humic substances. Water Res. 32, 3710–3716. Zhu, L., Ren, X., Yu, S., 1998. Use of cetyltrimethylammonium bromide–bentonite to remove organic contaminants of varying polar character from water. Environ. Sci. Technol. 32, 3374.