Action of silicic acid derived from sodium silicate precursor toward improving performances of porous gelatin membrane

To gain an insight into understanding how the silica network generated from hydrolysis and condensation of silicic acid, derived from sodium silicate, enhancing hydrothermal stability and mechanical properties of the leather, and particularly which active groups playing a main role for interaction of silica with collagen protein molecules, herein, effects of incorporated amino or carboxyl groups on the properties of silicic acid modified gelatin (GE) membrane were intensively studied. We found when lots of amino groups were introduced by adding a modified melamine, the thermal denaturation temperature, uniformity of pore diameter distribution and mechanical strength of GE membrane distinctly increased, while incorporating plenty of carboxyl groups by adding low polymerization degree acrylic acid polymer, no obvious change of performances of GE film was discovered. In addition, utilization of γ-glycidoxypropyltrimethoxysilane had a positive effect on the porosity and flexibility of GE membrane. Importantly, our results indicated that hydrogen bonding probably played the most important role toward improving performances of porous GE film when treated with silicic acid. These findings are greatly beneficial for developing a chrome-free tanning technology based on silicon containing materials, and are also suggestive for fabricating porous silica-GE hybrid materials using sodium silicate as a precursor. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48912.