INVESTIGATION OF PHYSICOCHEMICAL AND THERMAL PROPERTIES OF CLAY-HYDROGEL COMPOSITES

Abstract

Hydrogels are cross-linked polymeric networks which retain large amounts of water. The hydrogels with response capability to various stimuli such as pH and temperature have received great attention in many fields. In this study, hydrogels were synthesized by free radical solution polymerization through optimization of acrylamide/sodium acrylate mole ratio and ethylene glycol dimethacrylate content. With the addition of sepiolite as filler into the hydrogel network which had highest swelling percent, hydrogel composites were obtained. In the presence of 10 wt% sepiolite, maximum swelling percent was determined as approximately 10600%. Swelling properties of the hydrogel composite including 10 wt% sepiolite was investigated depending on pH, salt effect and temperature. With increasing pH value, swelling percent of the hydrogel composite showed an increase. At high temperatures, the hydrogel composite exhibited higher swelling percent. Swelling tests in 0.1 M NaCl, CaCl2 and FeCl3 solutions revealed that the lowest swelling percent was observed in 0.1 M FeCl3 solution. Fourier transform infrared spectroscopy (FTIR) analyses verified successfully preparation of the hydrogel composites. Regular layers of the sepiolite in the hydrogel network which made water diffusion easily were shown by scanning electron microscopy (SEM) analyses. Thermogravimetric analyses (TGA) indicated that thermal stability of the hydrogel network was increased with the addition of sepiolite.

Keywords

• Sepiolite
• Hydrogel
• Swelling Ratio
• Thermal Properties

Kil-Hidrojel Kompozitlerinin Fizikokimyasal ve Termal Özellikleri

Öz

Hidrojeller, yapısında fazla miktarda su tutabilen çapraz bağlı polimerik ağlardır. pH ve sıcaklık gibi çeşitli uyaranlara cevap verebilme kabiliyeti olan hidrojeller birçok alanda dikkat çekmektedir. Bu çalışmada akrilamit/sodyum akrilat mol oranının ve etilen glikol dimetakrilat miktarı optimize edilerek serbest radikal çözelti polimerizasyonu ile hidrojeller sentezlenmiştir. En yüksek şişme yüzdesine sahip olan hidrojel ağına dolgu maddesi olarak sepiyolit ilavesiyle hidrojel kompozitler hazırlanmıştır. Ağırlıkça %10 sepiyolit varlığında maksimum şişme yüzdesi yaklaşık %10600 olarak belirlenmiştir. pH, tuz etkisi ve sıcaklığa bağlı olarak ağırlıkça %10 sepiyolit içeren hidrojel kompozitin şişme özellikleri incelenmiştir. pH değerinin artışı ile hidrojel kompozitin şişme yüzdesi artış göstermiştir. Yüksek sıcaklıklarda hidrojel kompozit daha yüksek şişme yüzdesi göstermiştir. 0,1 M NaCl, CaCl2 and FeCl3 çözeltilerinde yapılan şişme testleri en düşük şişme yüzdesinin 0,1 M FeCl3 çözeltisi içerisinde olduğunu açığa çıkarmıştır. Fourier dönüşümlü kızılötesi spektroskopisi (FTIR) analizleri hidrojel kompozitlerin başarılı bir şekilde sentezlendiğini kanıtlamıştır. Kolay bir şekilde su difüzyonunu sağlayan sepiyolite ait düzenli tabakalar taramalı elektron mikroskobu (SEM) ile gösterilmiştir. Hidrojel ağının termal kararlılığının sepiyolit ilavesi ile arttırıldığı termogravimetrik analizler (TGA) ile belirlenmiştir.

Anahtar Kelimeler

• Sepiyolit
• Hidrojel
• Şişme Oranı
• Termal Özellikler

References

1. [1] W. A. Laftah, S. Hashim, and A. N. Ibrahim, "Polymer Hydrogels: A Review," Polymer-Plastics Technology and Engineering, vol. 50, no. 14, pp. 1475-1486, 2011.
2. [2] H. Huang, X. Qi, Y. Chen, and Z. Wu, "Thermo-sensitive hydrogels for delivering biotherapeutic molecules: A review," Saudi Pharmaceutical Journal, vol. 27, no. 7, pp. 990-999, 2019.
3. [3] M. Champeau, D. A. Heinze, T. N. Viana, E. R. de Souza, A. C. Chinellato, and S. Titotto, "4D Printing of Hydrogels: A Review," Advanced Functional Materials, vol. 30, no. 31, p. 1910606, 2020.
4. [4] O. Erol, A. Pantula, W. Liu, and D. H. Gracias, "Transformer Hydrogels: A Review," Advanced Materials Technologies, vol. 4, no. 4, p. 1900043, 2019.
5. [5] E. Karadağ, H. Ödemiş, S. Kundakçi, and Ö. B. Üzüm, "Swelling Characterization of Acrylamide/Zinc Acrylate/Xanthan Gum/Sepiolite Hybrid Hydrogels and Its Application in Sorption of Janus Green B from Aqueous Solutions," Advances in Polymer Technology, vol. 35, no. 3, pp. 248-259, 2016.
6. [6] P. Lavrador, M. R. Esteves, V. M. Gaspar, and J. F. Mano, "Stimuli‐Responsive Nanocomposite Hydrogels for Biomedical Applications," Advanced Functional Materials, vol. 31, no. 8, p. 2005941, 2020.
7. [7] S. Rafieian, H. Mirzadeh, H. Mahdavi, and M. E. Masoumi, "A review on nanocomposite hydrogels and their biomedical applications," Science and Engineering of Composite Materials, vol. 26, no. 1, pp. 154-174, 2019.
8. [8] E. Yilmaz, G. Guzel Kaya, and H. Deveci, "Preparation and characterization of pH-sensitive semi-interpenetrating network hybrid hydrogels with sodium humate and kaolin," Applied Clay Science, vol. 162, pp. 311-316, 2018.

9. [9] S. A. Khan, M. F. Siddiqui, and T. A. Khan, "Synthesis of Poly(methacrylic acid)/Montmorillonite Hydrogel Nanocomposite for Efficient Adsorption of Amoxicillin and Diclofenac from Aqueous Environment: Kinetic, Isotherm, Reusability, and Thermodynamic Investigations," ACS Omega, vol. 5, no. 6, pp. 2843-2855, 2020.
10. [10] S. J. Peighambardoust, O. Aghamohammadi-Bavil, R. Foroutan, and N. Arsalani, "Removal of malachite green using carboxymethyl cellulose-g-polyacrylamide/montmorillonite nanocomposite hydrogel," International Journal of Biological Macromolecules, vol. 159, pp. 1122-1131, 2020.
11. [11] B. Thakur et al., "Designing of bentonite based nanocomposite hydrogel for the adsorptive removal and controlled release of ampicillin," Journal of Molecular Liquids, vol. 319, p. 114166, 2020.
12. [12] D. Saraydın, H. N. Öztop, and C. Hepokur, "Nanocomposite smart hydrogel based on sepiolite nanochannels/N-isopropyl acrylamide/itaconic acid/acrylamide for invertase immobilization," Polymer-Plastics Technology and Materials, vol. 60, no. 1, pp. 25-36, 2021.
13. [13] H. N. Oztop, C. Hepokur, and D. Saraydin, "Acrylamide-sepiolite based composite hydrogels for immobilization of invertase," Journal of Food Science, vol. 74, no. 7, pp. N45-9, 2009.
14. [14] R. R. Palem et al., "Physicochemical characterization, drug release, and biocompatibility evaluation of carboxymethyl cellulose-based hydrogels reinforced with sepiolite nanoclay," International Journal of Biological Macromolecules, vol. 178, pp. 464-476, 2021.
15. [15] S. Kordjazi, K. Kamyab, and N. Hemmatinejad, "Super-hydrophilic/oleophobic chitosan/acrylamide hydrogel: an efficient water/oil separation filter," Advanced Composites and Hybrid Materials, vol. 3, no. 2, pp. 167-176, 2020.
16. [16] E. Karadağ and Ö. B. Üzüm, "A study on water and dye sorption capacities of novel ternary acrylamide/sodium acrylate/PEG semi IPN hydrogels," Polymer Bulletin, vol. 68, no. 5, pp. 1357-1368, 2011.
17. [17] K. Kabiri, H. Omidian, S. A. Hashemi, and M. J. Zohuriaan-Mehr, "Synthesis of fast-swelling superabsorbent hydrogels: effect of crosslinker type and concentration on porosity and absorption rate," European Polymer Journal, vol. 39, no. 7, pp. 1341-1348, 2003.
18. [18] F. Santiago, A. E. Mucientes, M. Osorio, and F. J. Poblete, "Synthesis and swelling behaviour of poly (sodium acrylate)/sepiolite superabsorbent composites and nanocomposites," Polymer International, vol. 55, no. 8, pp. 843-848, 2006.
19. [19] Y. Huang, M. Zeng, J. Ren, J. Wang, L. Fan, and Q. Xu, "Preparation and swelling properties of graphene oxide/poly(acrylic acid-co-acrylamide) super-absorbent hydrogel nanocomposites," Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 401, pp. 97-106, 2012.
20. [20] Y. Bao, J. Ma, and N. Li, "Synthesis and swelling behaviors of sodium carboxymethyl cellulose-g-poly(AA-co-AM-co-AMPS)/MMT superabsorbent hydrogel," Carbohydrate Polymers, vol. 84, no. 1, pp. 76-82, 2011.
21. [21] H. Namazi, M. Hasani, and M. Yadollahi, "Antibacterial oxidized starch/ZnO nanocomposite hydrogel: Synthesis and evaluation of its swelling behaviours in various pHs and salt solutions," International Journal of Biological Macromolecules, vol. 126, pp. 578-584, 2019.
22. [22] W. Tanan, J. Panichpakdee, and S. Saengsuwan, "Novel biodegradable hydrogel based on natural polymers: Synthesis, characterization, swelling/reswelling and biodegradability," European Polymer Journal, vol. 112, pp. 678-687, 2019.
23. [23] K. S. V. P. Chandrika, A. Singh, A. Rathore, and A. Kumar, "Novel cross linked guar gum-g-poly(acrylate) porous superabsorbent hydrogels: Characterization and swelling behaviour in different environments," Carbohydrate Polymers, vol. 149, pp. 175-185, 2016.
24. [24] M. R. Jozaghkar, A. Sepehrian Azar, and F. Ziaee, "Preparation, Characterization, and swelling study of N,N’-dimethylacrylamide/acrylic acid amphiphilic hydrogels in different conditions," Polymer Bulletin, vol. 79, no. 7, pp. 5183-5195, 2022.
25. [25] Y. M. Mohan, J. P. Dickson, and K. E. Geckeler, "Swelling and diffusion characteristics of novel semi-interpenetrating network hydrogels composed of poly[(acrylamide)- co-(sodium acrylate)] and poly[(vinylsulfonic acid), sodium salt]," Polymer International, vol. 56, no. 2, pp. 175-185, 2007.
26. [26] Y. M. Mohan, T. Premkumar, D. K. Joseph, and K. E. Geckeler, "Stimuli-responsive poly(N-isopropylacrylamide-co-sodium acrylate) hydrogels: A swelling study in surfactant and polymer solutions," Reactive and Functional Polymers, vol. 67, no. 9, pp. 844-858, 2007.
27. [27] M. M. Ghobashy et al., "Characterization of Starch-based three components of gamma-ray cross-linked hydrogels to be used as a soil conditioner," Materials Science and Engineering: B, vol. 260, p. 114645, 2020.
28. [28] J. Zhang, L. Wang, and A. Wang, "Preparation and Swelling Behavior of Fast-Swelling Superabsorbent Hydrogels Based On Starch-g-Poly(acrylic acid-co-sodium acrylate)," Macromolecular Materials and Engineering, vol. 291, no. 6, pp. 612-620, 2006.
29. [29] F. B. Santos, N. T. Miranda, M. I. R. B. Schiavon, L. V. Fregolente, and M. R. Wolf Maciel, "Thermal degradation kinetic of poly(acrylamide-co-sodium acrylate) hydrogel applying isoconversional methods," Journal of Thermal Analysis and Calorimetry, vol. 146, no. 6, pp. 2503-2514, 2021.
30. [30] A. Olad, M. Eslamzadeh, and A. Mirmohseni, "Ion crosslinked poly(acrylic acid-co-acrylamide)/poly(vinyl alcohol)/Cloisite 15A nanocomposite hydrogels as potential wound dressing films: Effect of clay content on water absorption kinetic and mechanical properties," Polymer Composites, vol. 40, no. 5, pp. 1762-1773, 2019.
31. [31] S. Zhumagaliyeva, R. Iminovа, G. Kairalapova, М. M. Beysebekov, M. K. Beysebekov, and Z. Abilov, "Composite Polymer-Clay Hydrogels Based on Bentonite Clay and Acrylates: Synthesis, Characterization and Swelling Capacity," Eurasian Chemico-Technological Journal, vol. 19, no. 3, p. 279, 2017.
32. [32] R. Ianchis et al., "Novel Hydrogel-Advanced Modified Clay Nanocomposites as Possible Vehicles for Drug Delivery and Controlled Release," Nanomaterials (Basel), vol. 7, no. 12, 2017.
33. [33] S. G. Abd Alla, R. H. Helal, A. A. F. Wasfy, and A. W. M. El-Naggar, "Structure-property and swelling behavior of electron beam irradiated poly(vinyl alcohol)/acrylamide/sodium montmorillonite clay composites," Journal of Applied Polymer Science, vol. 121, no. 5, pp. 2634-2643, 2011.
34. [34] E. Farid, E. A. Kamoun, T. H. Taha, A. El-Dissouky, and T. E. Khalil, "PVA/CMC/Attapulgite Clay Composite Hydrogel Membranes for Biomedical Applications: Factors Affecting Hydrogel Membranes Crosslinking and Bio-evaluation Tests," Journal of Polymers and the Environment, vol. 30, no. 11, pp. 4675-4689, 2022.
35. [35] S. Datta Chaudhuri, A. Mandal, A. Dey, and D. Chakrabarty, "Tuning the swelling and rheological attributes of bentonite clay modified starch grafted polyacrylic acid based hydrogel," Applied Clay Science, vol. 185, p. 105405, 2020.
36. [36] L. Bounabi, N. B. Mokhnachi, N. Haddadine, F. Ouazib, and R. Barille, "Development of poly(2-hydroxyethyl methacrylate)/clay composites as drug delivery systems of paracetamol," Journal of Drug Delivery Science and Technology, vol. 33, pp. 58-65, 2016.