Organic–inorganic hybrid materials have emerged as a versatile class of advanced materials that integrate the flexibility and functionality of organic polymers with the thermal, mechanical, and chemical stability of inorganic networks. Among the available fabrication routes, the sol–gel process has gained considerable attention because of its simplicity, low processing temperature, compositional flexibility, and ability to tailor material properties at the molecular level. The present review discusses the synthesis and characterization of polymer-based hybrid materials prepared through sol–gel processing, with particular emphasis on gelatin–silica, gelatin–silica–titania, and poly (2-hydroxypropyl methacrylate) (HPMA)–silica–titania systems. The hydrolysis and condensation of silica and titanium alkoxide precursors generate interconnected inorganic frameworks within polymer matrices, resulting in materials possessing high surface area, porosity, mechanical stability, and functional versatility. The influence of synthesis parameters, precursor chemistry, and polymer–inorganic interactions on the resulting microstructure is discussed. Different characterization techniques like Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and Brunauer–Emmett–Teller (BET) surface area analysis have been discussed. The structure–property relationships governing adsorption behavior, thermal stability, mechanical performance, and biocompatibility are highlighted. Applications in wastewater treatment, drug delivery, catalysis, biomedical engineering, and environmental remediation are also discussed. The review demonstrates that sol–gel-derived hybrid materials offer a promising platform for the development of multifunctional materials for advanced technological applications. Keywords: Sol–gel process; Organic–inorganic hybrids; Gelatin; Silica; Titania; HPMA; Characterization; Hybrid nanomaterials.

Keywords: Sol–gel process; Organic–inorganic hybrids; Gelatin; Silica; Titania; HPMA; Characterization; Hybrid nanomaterials.

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1. Alves, N. M.; Mano, J. F. Chitosan Derivatives Obtained by Chemical Modifications for Biomedical and Environmental Applications. J. Biol. Macromol. 2008, 43 (5), 401–414.
2. Ashbrook, S. E.; Dawson, D. M. Solid-State NMR Spectroscopy for Characterization of Hybrid Materials. Chem. Res. 2023, 56, 1450–1462.
3. Attia, Y. A., Ed. Sol–Gel Processing and Applications; Springer Science & Business Media: Dordrecht, The Netherlands, 2012.
4. Bohidar, H. B.; Jena, S. S. Kinetics of Sol–Gel Transition in Thermoreversible Gelation of Gelatin. Chem. Phys. 1993, 98 (11), 8970–8977.
5. Bokobza, L.; Diop, A. L. Reinforcement of Poly(dimethylsiloxane) by Sol–Gel in Situ Generated Silica and Titania Particles. Express Polym. Lett. 2010, 4 (6), 355–363.
6. Briggs, D.; Grant, J. T. Surface Analysis by Auger and X-ray Photoelectron Spectroscopy; IM Publications: Chichester, U.K., 2021.
7. Brinker, C. J., & Scherer, G. W. (1990). Sol-gel science: the physics and chemistry of sol-gel processing. Gulf Professional Publishing.
8. Brinker, C. J.; Hurd, A. J. Fundamentals of Sol–Gel Dip-Coating. Phys. III Fr. 1994, 4 (7), 1231–1242.

1. Brinker, C. J.; Scherer, G. W. Sol–Gel Science: The Physics and Chemistry of Sol–Gel Processing; Academic Press: San Diego, CA, 2013.

10. Butler, K. T.; Davies, D. W.; Cartwright, H.; Isayev, O.; Walsh, A. Machine Learning for Molecular and Materials Science. Nature 2018, 559, 547–555.
11. Choi, S. M.; Singh, D.; Cho, Y. W.; Oh, T. H.; Han, S. S. Three-Dimensional Porous HPMA-co-DMAEM Hydrogels for Biomedical Application. Colloid Polym. Sci. 2013, 291 (5), 1121–1133.
12. Coradin, T.; Allouche, J.; Boissière, M.; Livage, J. Sol–Gel Biopolymer/Silica Nanocomposites in Biotechnology. Nanosci. 2006, 2 (3), 219–230.
13. Dehghanghadikolaei, A.; Ansary, J.; Ghoreishi, R. Sol–Gel Process Applications: A Mini-Review. Nat. Res. Soc. 2018, 2 (1), 02008–02029.
14. Kessler, V. G.; Seisenbaeva, G. A. Molecular Mechanisms of Sol–Gel Processing Investigated by Advanced Spectroscopic Techniques. Sol-Gel Sci. Technol. 2023, 107, 190–200.
15. Fahmi, A.; Pietsch, T.; Mendoza, C.; Cheval, N. Functional Hybrid Materials. Today 2009, 12 (5), 44–50.
16. Gómez-Romero, P.; Sanchez, C. Hybrid Materials, Functional Applications: An Introduction. In Functional Hybrid Materials; Gómez-Romero, P., Sanchez, C., Eds.; Wiley-VCH: Weinheim, Germany, 2004; pp 1–14.
17. Gun'ko, V. M.; Zarko, V. I.; Chibowski, E.; Dudnik, V. V.; Leboda, R.; Zaets, V. A. Structure of Fumed Titania and Silica/Titania and Influence of the Nature of Surface Sites on Interaction with Water. Colloid Interface Sci. 1997, 188 (1), 39–57.
18. Jamwal, H. S.; Kumari, S.; Chauhan, G. S.; Ahn, J. H.; Reddy, N. S. New Silica–Titania Based Polymeric Hybrid Materials for the Removal of Cu(II) Ions from Their Aqueous Solutions. Environ. Chem. Eng. 2016, 4 (2), 2518–2528.
19. Kalia, S.; Avérous, L. Biopolymers: Biomedical and Environmental Applications; John Wiley & Sons: Hoboken, NJ, 2011.
20. Kallingal, N.; Ramakrishnan, R.; Krishnan, V. K. Formulation and Characterization of Gelatin Methacrylamide–Hydroxypropyl Methacrylate Based Bioink for Bioprinting Applications. Biomater. Sci., Polym. Ed. 2023, 34 (6), 768–790.

1. Kickelbick, G. Concepts for the Incorporation of Inorganic Building Blocks into Organic Polymers on a Nanoscale. Prog. Polym. Sci. 2003, 28 (1), 83–114.

22. Klein, L., Aparicio, M., & Jitianu, A. (Eds.). (2018). Handbook of sol-gel science and technology: Processing, characterization and applications. Springer Nature.  Ramsey, J. D. F. Sol–Gel Processing. In Controlled Particle, Droplet and Bubble Formation; Cambridge University Press: Cambridge, U.K., 1994; pp 1–38.
23. Lenza, R. F.; Vasconcelos, W. L. Synthesis of Titania–Silica Materials by Sol–Gel. Res. 2002, 5 (4), 497–502.
24. Li, Q., Ed. Functional Organic and Hybrid Nanostructured Materials: Fabrication, Properties, and Applications; John Wiley & Sons: Hoboken, NJ, 2018.Bottom of Form

1. Livage, J.; Henry, M.; Sanchez, C. Sol–Gel Chemistry of Transition Metal Oxides. Prog. Solid State Chem. 1988, 18 (4), 259–341.

26. Mahltig, B.; Leisegang, T.; Jakubik, M. Recent Developments in Functional Hybrid Sol–Gel Materials and Coatings. Sol-Gel Sci. Technol. 2023, 107, 20–31.
27. Mamidi, N.; Delgadillo, R. M.; Sustaita, A. O.; Lozano, K.; Yallapu, M. M. Current Nanocomposite Advances for Biomedical and Environmental Application Diversity. Res. Rev. 2025, 45 (2), 576–628.
28. Mikhailov, O. V. Sol–Gel Technology and Template Synthesis in Thin Gelatin Films. Sol-Gel Sci. Technol. 2014, 72 (2), 314–327.

1. Nicole, L.; Rozes, L.; Sanchez, C. Integrative Approaches to Hybrid Multifunctional Materials: From Multidisciplinary Research to Applied Technologies. Adv. Mater. 2010, 22 (30), 3208–3214.

30. Nithusha, K. Development of Gelatin Methacrylamide–Hydroxypropyl Methacrylate Based Bioink; Doctoral Dissertation, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Thiruvananthapuram, India, 2017.

1. Pezzella, A.; Guarino, V.; Ambrosio, L. Biopolymer-Based Hybrid Materials for Tissue Engineering and Drug Delivery Applications. Materials 2021, 14 (18), 5432.

32. Povolotskaya, A. V.; Povolotskiy, A. V.; Manshina, A. A. Hybrid Nanostructures: Synthesis, Morphology and Functional Properties. Chem. Rev. 2015, 84 (6), 579–600.
33. Roy, D.; Cambre, J. N.; Sumerlin, B. S. Future Perspectives and Recent Advances in Stimuli-Responsive Materials. Polym. Sci. 2010, 35, 278–301. Reyes-Peces, M. V.; Sánchez-Salcedo, S.; Vallet-Regí, M. Bioactive Organic–Inorganic Hybrid Materials for Regenerative Medicine. Gels 2023, 9, 67.
34. Sakka, S. (Ed.). (2005). Handbook of sol-gel science and technology. 1. Sol-gel processing(Vol. 1). Springer Science & Business Media
35. Samuel, M. S.; Ravikumar, M.; John, A. J.; Selvarajan, E.; Patel, H.; Chander, P. S.; Chandrasekar, N. A Review on Green Synthesis of Nanoparticles and Their Diverse Biomedical and Environmental Applications. Catalysts 2022, 12 (5), 459.
36. Sanchez, C.; Belleville, P.; Popall, M.; Nicole, L. Applications of Advanced Hybrid Organic Inorganic Nanomaterials: From Laboratory to Market. Soc. Rev. 2011, 40, 696–753.

1. Sanchez, C.; Julián, B.; Belleville, P.; Popall, M. Applications of Hybrid Organic–Inorganic Nanocomposites. J. Mater. Chem. 2005, 15 (35–36), 3559–3592.

38. Satchanska, G.; Davidova, S.; Petrov, P. D. Natural and Synthetic Polymers for Biomedical and Environmental Applications. Polymers 2024, 16 (8), 1159.

1. Schottner, G. Hybrid Sol–Gel-Derived Polymers: Applications of Multifunctional Materials. Chem. Mater. 2001, 13 (10), 3422–3435.

40. Schubert, U. (2015). Chemistry and fundamentals of the sol–gel process. The sol‐gel handbook, 1-28.
41. Seriani, N.; Pinilla, C.; Cereda, S.; De Vita, A.; Scandolo, S. Titania–Silica Interfaces. Phys. Chem. C 2012, 116 (20), 11062–11067.
42. Smitha, S.; Mukundan, P.; Pillai, P. K.; Warrier, K. G. K. Silica–Gelatin Bio-Hybrid and Transparent Nano-Coatings through Sol–Gel Technique. Chem. Phys. 2007, 103 (2–3), 318–322.
43. Smitha, S.; Shajesh, P.; Mukundan, P.; Nair, T. D. R.; Warrier, K. G. K. Synthesis of Biocompatible Hydrophobic Silica–Gelatin Nano-Hybrid by Sol–Gel Process. Colloids Surf., B 2007, 55 (1), 38–43.

1. Soares, S. F.; Daniel-da-Silva, A. L.; Trindade, T. Functional Organic–Inorganic Hybrid Nanomaterials Prepared by Sol–Gel Processing. J. Sol-Gel Sci. Technol. 2023, 107 (1), 201–214.

45. Soares, S. F.; Daniel-da-Silva, A. L.; Trindade, T. Green Sol–Gel Strategies for Sustainable Hybrid Materials. Sol-Gel Sci. Technol. 2023, 107, 201–214.
46. Staykov, A.; Ferreira-Neto, E. P.; Cruz, J. M. Y. S.; Ullah, S.; Rodrigues-Filho, U. P. The Stability of Titania–Silica Interface. J. Quantum Chem. 2018, 118 (4), e25495.
47. Sun, Q.; Yang, Z.; Qi, X. Design and Application of Hybrid Polymer–Protein Systems in Cancer Therapy. Polymers 2023, 15 (9), 2219.
48. Sur, G. S.; Mark, J. E. Elastomeric Networks Cross-Linked by Silica or Titania Fillers. Polym. J. 1985, 21 (12), 1051–1052.
49. Tat’yana, G. K.; Safronov, A. P.; Shadrina, E. V.; Ivanenko, M. V.; Suvorova, A. I.; Chupakhin, O. N. Mechanism of Structural Networking in Hydrogels Based on Silicon and Titanium Glycerolates. Colloid Interface Sci. 2012, 365 (1), 81–89.
50. Thakur, S. S. Gelatin–EiO₂ (Ei = Si, Ti, Zr) Based Mesoporous Nano-Hybrids: Synthesis and Characterization. Mater. Metall. Eng. 2025, 14 (3), 31–64.
51. Thakur, S. S.; Chauhan, G. S. Gelatin–Silica-Based Hybrid Materials as Efficient Candidates for Removal of Chromium(VI) from Aqueous Solutions. Eng. Chem. Res. 2014, 53 (12), 4838–4849.
52. Thakur, S. S.; Chauhan, G. S. Titania–Gelatin-Based Nanohybrids: A Versatile Material for Removal of Organic Dyes (Congo Red, Malachite Green, Crystal Violet and Methylene Blue) from Aqueous Solution. In Advances in Polymer Sciences and Technology: Select Papers from APA 2017; Springer: Singapore, 2018; pp 147–176.
53. Thakur, S. S.; Kumar, A.; Chauhan, G. S. Cellulase Immobilization onto Zirconia–Gelatin-Based Mesoporous Hybrid Matrix for Efficient Cellulose Hydrolysis. Trends Carbohydr. Res. 2018, 10 (1), 1–12.
54. Verma, C.; Verma, D. K.; Berdimurodov, E.; Barsoum, I.; Alfantazi, A.; Hussain, C. M. Green Magnetic Nanoparticles: A Comprehensive Review of Recent Progress in Biomedical and Environmental Applications. Mater. Sci. 2024, 59 (2), 325–358.
55. Wang, Y.; Dong, M.; Guo, M.; Wang, X.; Zhou, J.; Lei, J.; Qin, C. Agar/Gelatin Bilayer Gel Matrix Fabricated by Simple Thermo-Responsive Sol–Gel Transition Method. Sci. Eng. C 2017, 77, 293–299.
56. Watzke, H. J.; Dieschbourg, C. Novel Silica–Biopolymer Nanocomposites: The Silica Sol–Gel Process in Biopolymer Organogels. Colloid Interface Sci. 1994, 50, 1–14.

1. Yapa, P.; Munaweera, I. Functionalized Nanoporous Hybrid Materials for Environmental and Biomedical Applications. J. Mater. Chem. B 2025, 13 (12), 10715–10742.

58. Yapa, P.; Munaweera, I. Functionalized Nanoporous Hybrid Materials for Environmental and Biomedical Applications. Mater. Chem. B 2025, 13, 10715–10742.
59. Zak, A. K.; Esmaeilzadeh, J.; Hashim, A. M. Exploring the Gelatin-Based Sol–Gel Approach: A Convenient Route for Fabricating High-Quality Pure and Doped ZnO Nanostructures. Int. 2024, 50 (8), 12649–12663.
60. Zhai, M.; Ma, F.; Li, J.; Wan, B.; Yu, N. Preparation and Properties of Cryogel Based on Poly(hydroxypropyl methacrylate). Biomater. Sci., Polym. Ed. 2018, 29 (12), 1401–1425.

Organic–inorganic hybrid materials have emerged as a versatile class of advanced materials that integrate the flexibility and functionality of organic polymers with the thermal, mechanical, and chemical stability of inorganic networks. Among the available fabrication routes, the sol–gel process has gained considerable attention because of its simplicity, low processing temperature, compositional flexibility, and ability to tailor material properties at the molecular level. The present review discusses the synthesis and characterization of polymer-based hybrid materials prepared through sol–gel processing, with particular emphasis on gelatin–silica, gelatin–silica–titania, and poly (2-hydroxypropyl methacrylate) (HPMA)–silica–titania systems. The hydrolysis and condensation of silica and titanium alkoxide precursors generate interconnected inorganic frameworks within polymer matrices, resulting in materials possessing high surface area, porosity, mechanical stability, and functional versatility. The influence of synthesis parameters, precursor chemistry, and polymer–inorganic interactions on the resulting microstructure is discussed. Different characterization techniques like Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and Brunauer–Emmett–Teller (BET) surface area analysis have been discussed. The structure–property relationships governing adsorption behavior, thermal stability, mechanical performance, and biocompatibility are highlighted. Applications in wastewater treatment, drug delivery, catalysis, biomedical engineering, and environmental remediation are also discussed. The review demonstrates that sol–gel-derived hybrid materials offer a promising platform for the development of multifunctional materials for advanced technological applications. Keywords: Sol–gel process; Organic–inorganic hybrids; Gelatin; Silica; Titania; HPMA; Characterization; Hybrid nanomaterials.

Keywords: Sol–gel process; Organic–inorganic hybrids; Gelatin; Silica; Titania; HPMA; Characterization; Hybrid nanomaterials.

🔒 This is a subscription article

Full text is available to subscribers and institutional members. Please choose an option below to access it.

1. Alves, N. M.; Mano, J. F. Chitosan Derivatives Obtained by Chemical Modifications for Biomedical and Environmental Applications. J. Biol. Macromol. 2008, 43 (5), 401–414.
2. Ashbrook, S. E.; Dawson, D. M. Solid-State NMR Spectroscopy for Characterization of Hybrid Materials. Chem. Res. 2023, 56, 1450–1462.
3. Attia, Y. A., Ed. Sol–Gel Processing and Applications; Springer Science & Business Media: Dordrecht, The Netherlands, 2012.
4. Bohidar, H. B.; Jena, S. S. Kinetics of Sol–Gel Transition in Thermoreversible Gelation of Gelatin. Chem. Phys. 1993, 98 (11), 8970–8977.
5. Bokobza, L.; Diop, A. L. Reinforcement of Poly(dimethylsiloxane) by Sol–Gel in Situ Generated Silica and Titania Particles. Express Polym. Lett. 2010, 4 (6), 355–363.
6. Briggs, D.; Grant, J. T. Surface Analysis by Auger and X-ray Photoelectron Spectroscopy; IM Publications: Chichester, U.K., 2021.
7. Brinker, C. J., & Scherer, G. W. (1990). Sol-gel science: the physics and chemistry of sol-gel processing. Gulf Professional Publishing.
8. Brinker, C. J.; Hurd, A. J. Fundamentals of Sol–Gel Dip-Coating. Phys. III Fr. 1994, 4 (7), 1231–1242.

1. Brinker, C. J.; Scherer, G. W. Sol–Gel Science: The Physics and Chemistry of Sol–Gel Processing; Academic Press: San Diego, CA, 2013.

10. Butler, K. T.; Davies, D. W.; Cartwright, H.; Isayev, O.; Walsh, A. Machine Learning for Molecular and Materials Science. Nature 2018, 559, 547–555.
11. Choi, S. M.; Singh, D.; Cho, Y. W.; Oh, T. H.; Han, S. S. Three-Dimensional Porous HPMA-co-DMAEM Hydrogels for Biomedical Application. Colloid Polym. Sci. 2013, 291 (5), 1121–1133.
12. Coradin, T.; Allouche, J.; Boissière, M.; Livage, J. Sol–Gel Biopolymer/Silica Nanocomposites in Biotechnology. Nanosci. 2006, 2 (3), 219–230.
13. Dehghanghadikolaei, A.; Ansary, J.; Ghoreishi, R. Sol–Gel Process Applications: A Mini-Review. Nat. Res. Soc. 2018, 2 (1), 02008–02029.
14. Kessler, V. G.; Seisenbaeva, G. A. Molecular Mechanisms of Sol–Gel Processing Investigated by Advanced Spectroscopic Techniques. Sol-Gel Sci. Technol. 2023, 107, 190–200.
15. Fahmi, A.; Pietsch, T.; Mendoza, C.; Cheval, N. Functional Hybrid Materials. Today 2009, 12 (5), 44–50.
16. Gómez-Romero, P.; Sanchez, C. Hybrid Materials, Functional Applications: An Introduction. In Functional Hybrid Materials; Gómez-Romero, P., Sanchez, C., Eds.; Wiley-VCH: Weinheim, Germany, 2004; pp 1–14.
17. Gun'ko, V. M.; Zarko, V. I.; Chibowski, E.; Dudnik, V. V.; Leboda, R.; Zaets, V. A. Structure of Fumed Titania and Silica/Titania and Influence of the Nature of Surface Sites on Interaction with Water. Colloid Interface Sci. 1997, 188 (1), 39–57.
18. Jamwal, H. S.; Kumari, S.; Chauhan, G. S.; Ahn, J. H.; Reddy, N. S. New Silica–Titania Based Polymeric Hybrid Materials for the Removal of Cu(II) Ions from Their Aqueous Solutions. Environ. Chem. Eng. 2016, 4 (2), 2518–2528.
19. Kalia, S.; Avérous, L. Biopolymers: Biomedical and Environmental Applications; John Wiley & Sons: Hoboken, NJ, 2011.
20. Kallingal, N.; Ramakrishnan, R.; Krishnan, V. K. Formulation and Characterization of Gelatin Methacrylamide–Hydroxypropyl Methacrylate Based Bioink for Bioprinting Applications. Biomater. Sci., Polym. Ed. 2023, 34 (6), 768–790.

1. Kickelbick, G. Concepts for the Incorporation of Inorganic Building Blocks into Organic Polymers on a Nanoscale. Prog. Polym. Sci. 2003, 28 (1), 83–114.

22. Klein, L., Aparicio, M., & Jitianu, A. (Eds.). (2018). Handbook of sol-gel science and technology: Processing, characterization and applications. Springer Nature.  Ramsey, J. D. F. Sol–Gel Processing. In Controlled Particle, Droplet and Bubble Formation; Cambridge University Press: Cambridge, U.K., 1994; pp 1–38.
23. Lenza, R. F.; Vasconcelos, W. L. Synthesis of Titania–Silica Materials by Sol–Gel. Res. 2002, 5 (4), 497–502.
24. Li, Q., Ed. Functional Organic and Hybrid Nanostructured Materials: Fabrication, Properties, and Applications; John Wiley & Sons: Hoboken, NJ, 2018.Bottom of Form

1. Livage, J.; Henry, M.; Sanchez, C. Sol–Gel Chemistry of Transition Metal Oxides. Prog. Solid State Chem. 1988, 18 (4), 259–341.

26. Mahltig, B.; Leisegang, T.; Jakubik, M. Recent Developments in Functional Hybrid Sol–Gel Materials and Coatings. Sol-Gel Sci. Technol. 2023, 107, 20–31.
27. Mamidi, N.; Delgadillo, R. M.; Sustaita, A. O.; Lozano, K.; Yallapu, M. M. Current Nanocomposite Advances for Biomedical and Environmental Application Diversity. Res. Rev. 2025, 45 (2), 576–628.
28. Mikhailov, O. V. Sol–Gel Technology and Template Synthesis in Thin Gelatin Films. Sol-Gel Sci. Technol. 2014, 72 (2), 314–327.

1. Nicole, L.; Rozes, L.; Sanchez, C. Integrative Approaches to Hybrid Multifunctional Materials: From Multidisciplinary Research to Applied Technologies. Adv. Mater. 2010, 22 (30), 3208–3214.

30. Nithusha, K. Development of Gelatin Methacrylamide–Hydroxypropyl Methacrylate Based Bioink; Doctoral Dissertation, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Thiruvananthapuram, India, 2017.

1. Pezzella, A.; Guarino, V.; Ambrosio, L. Biopolymer-Based Hybrid Materials for Tissue Engineering and Drug Delivery Applications. Materials 2021, 14 (18), 5432.

32. Povolotskaya, A. V.; Povolotskiy, A. V.; Manshina, A. A. Hybrid Nanostructures: Synthesis, Morphology and Functional Properties. Chem. Rev. 2015, 84 (6), 579–600.
33. Roy, D.; Cambre, J. N.; Sumerlin, B. S. Future Perspectives and Recent Advances in Stimuli-Responsive Materials. Polym. Sci. 2010, 35, 278–301. Reyes-Peces, M. V.; Sánchez-Salcedo, S.; Vallet-Regí, M. Bioactive Organic–Inorganic Hybrid Materials for Regenerative Medicine. Gels 2023, 9, 67.
34. Sakka, S. (Ed.). (2005). Handbook of sol-gel science and technology. 1. Sol-gel processing(Vol. 1). Springer Science & Business Media
35. Samuel, M. S.; Ravikumar, M.; John, A. J.; Selvarajan, E.; Patel, H.; Chander, P. S.; Chandrasekar, N. A Review on Green Synthesis of Nanoparticles and Their Diverse Biomedical and Environmental Applications. Catalysts 2022, 12 (5), 459.
36. Sanchez, C.; Belleville, P.; Popall, M.; Nicole, L. Applications of Advanced Hybrid Organic Inorganic Nanomaterials: From Laboratory to Market. Soc. Rev. 2011, 40, 696–753.

1. Sanchez, C.; Julián, B.; Belleville, P.; Popall, M. Applications of Hybrid Organic–Inorganic Nanocomposites. J. Mater. Chem. 2005, 15 (35–36), 3559–3592.

38. Satchanska, G.; Davidova, S.; Petrov, P. D. Natural and Synthetic Polymers for Biomedical and Environmental Applications. Polymers 2024, 16 (8), 1159.

1. Schottner, G. Hybrid Sol–Gel-Derived Polymers: Applications of Multifunctional Materials. Chem. Mater. 2001, 13 (10), 3422–3435.

40. Schubert, U. (2015). Chemistry and fundamentals of the sol–gel process. The sol‐gel handbook, 1-28.
41. Seriani, N.; Pinilla, C.; Cereda, S.; De Vita, A.; Scandolo, S. Titania–Silica Interfaces. Phys. Chem. C 2012, 116 (20), 11062–11067.
42. Smitha, S.; Mukundan, P.; Pillai, P. K.; Warrier, K. G. K. Silica–Gelatin Bio-Hybrid and Transparent Nano-Coatings through Sol–Gel Technique. Chem. Phys. 2007, 103 (2–3), 318–322.
43. Smitha, S.; Shajesh, P.; Mukundan, P.; Nair, T. D. R.; Warrier, K. G. K. Synthesis of Biocompatible Hydrophobic Silica–Gelatin Nano-Hybrid by Sol–Gel Process. Colloids Surf., B 2007, 55 (1), 38–43.

1. Soares, S. F.; Daniel-da-Silva, A. L.; Trindade, T. Functional Organic–Inorganic Hybrid Nanomaterials Prepared by Sol–Gel Processing. J. Sol-Gel Sci. Technol. 2023, 107 (1), 201–214.

45. Soares, S. F.; Daniel-da-Silva, A. L.; Trindade, T. Green Sol–Gel Strategies for Sustainable Hybrid Materials. Sol-Gel Sci. Technol. 2023, 107, 201–214.
46. Staykov, A.; Ferreira-Neto, E. P.; Cruz, J. M. Y. S.; Ullah, S.; Rodrigues-Filho, U. P. The Stability of Titania–Silica Interface. J. Quantum Chem. 2018, 118 (4), e25495.
47. Sun, Q.; Yang, Z.; Qi, X. Design and Application of Hybrid Polymer–Protein Systems in Cancer Therapy. Polymers 2023, 15 (9), 2219.
48. Sur, G. S.; Mark, J. E. Elastomeric Networks Cross-Linked by Silica or Titania Fillers. Polym. J. 1985, 21 (12), 1051–1052.
49. Tat’yana, G. K.; Safronov, A. P.; Shadrina, E. V.; Ivanenko, M. V.; Suvorova, A. I.; Chupakhin, O. N. Mechanism of Structural Networking in Hydrogels Based on Silicon and Titanium Glycerolates. Colloid Interface Sci. 2012, 365 (1), 81–89.
50. Thakur, S. S. Gelatin–EiO₂ (Ei = Si, Ti, Zr) Based Mesoporous Nano-Hybrids: Synthesis and Characterization. Mater. Metall. Eng. 2025, 14 (3), 31–64.
51. Thakur, S. S.; Chauhan, G. S. Gelatin–Silica-Based Hybrid Materials as Efficient Candidates for Removal of Chromium(VI) from Aqueous Solutions. Eng. Chem. Res. 2014, 53 (12), 4838–4849.
52. Thakur, S. S.; Chauhan, G. S. Titania–Gelatin-Based Nanohybrids: A Versatile Material for Removal of Organic Dyes (Congo Red, Malachite Green, Crystal Violet and Methylene Blue) from Aqueous Solution. In Advances in Polymer Sciences and Technology: Select Papers from APA 2017; Springer: Singapore, 2018; pp 147–176.
53. Thakur, S. S.; Kumar, A.; Chauhan, G. S. Cellulase Immobilization onto Zirconia–Gelatin-Based Mesoporous Hybrid Matrix for Efficient Cellulose Hydrolysis. Trends Carbohydr. Res. 2018, 10 (1), 1–12.
54. Verma, C.; Verma, D. K.; Berdimurodov, E.; Barsoum, I.; Alfantazi, A.; Hussain, C. M. Green Magnetic Nanoparticles: A Comprehensive Review of Recent Progress in Biomedical and Environmental Applications. Mater. Sci. 2024, 59 (2), 325–358.
55. Wang, Y.; Dong, M.; Guo, M.; Wang, X.; Zhou, J.; Lei, J.; Qin, C. Agar/Gelatin Bilayer Gel Matrix Fabricated by Simple Thermo-Responsive Sol–Gel Transition Method. Sci. Eng. C 2017, 77, 293–299.
56. Watzke, H. J.; Dieschbourg, C. Novel Silica–Biopolymer Nanocomposites: The Silica Sol–Gel Process in Biopolymer Organogels. Colloid Interface Sci. 1994, 50, 1–14.

1. Yapa, P.; Munaweera, I. Functionalized Nanoporous Hybrid Materials for Environmental and Biomedical Applications. J. Mater. Chem. B 2025, 13 (12), 10715–10742.

58. Yapa, P.; Munaweera, I. Functionalized Nanoporous Hybrid Materials for Environmental and Biomedical Applications. Mater. Chem. B 2025, 13, 10715–10742.
59. Zak, A. K.; Esmaeilzadeh, J.; Hashim, A. M. Exploring the Gelatin-Based Sol–Gel Approach: A Convenient Route for Fabricating High-Quality Pure and Doped ZnO Nanostructures. Int. 2024, 50 (8), 12649–12663.
60. Zhai, M.; Ma, F.; Li, J.; Wan, B.; Yu, N. Preparation and Properties of Cryogel Based on Poly(hydroxypropyl methacrylate). Biomater. Sci., Polym. Ed. 2018, 29 (12), 1401–1425.