引入静电相互作用的SiO_(2)纳米复合水凝胶制备及其性能研究

A study on the preparation and performance of SiO_(2)nanocomposite hydrogels with electrostatic interactions

提升纳米粒子与凝胶高分子网络的结合程度以改善两者之间的异质性,对于提升纳米复合水凝胶的力学性能极为关键。为此,在纳米复合水凝胶中引入静电相互作用,进一步提升复合凝胶的力学性能。首先,对纳米二氧化硅(SiO_(2))进行表面改性,制备聚对苯乙烯磺酸钠(PSS)接枝的PSS-SiO_(2)纳米粒子;再将其与聚N,N,N-三甲基-3-(2-甲基烯丙酰氨基)-1-氯化丙铵(PMPTC)共聚改性的聚丙烯酰胺(PAM)水凝胶复合,制备得到PSS-SiO_(2)/P(AM-co-MPTC)纳米复合水凝胶;研究PSS-SiO_(2)/P(AM-co-MPTC)复合水凝胶中PSS-SiO_(2)纳米粒子的—SO-3与PMPTC的—N+(CH3)3间的静电相互作用对其微观形貌、溶胀性能、流变性能和力学性能的影响。结果表明:通过PSS-SiO_(2)纳米粒子表面聚阴离子与水凝胶网络聚阳离子间形成的静电相互作用,SiO_(2)纳米粒子与水凝胶基体间的结合程度显著增强。与添加纯SiO_(2)纳米粒子的SiO_(2)/P(AM-co-MPTC)纳米复合水凝胶相比,添加PSS-SiO_(2)纳米粒子的PSS-SiO_(2)/P(AM-co-MPTC)纳米复合水凝胶力学性能提升明显,最优组分的拉伸模量可达160.9kPa、强度为95.7kPa、韧性为31.1kJ/m3,分别提高了176%、297%和556%,并表现出反聚电解质效应的盐响应行为。该研究表明,纳米粒子与复合凝胶基体之间静电相互作用的引入,有助于进一步提升复合水凝胶的力学性能,同时赋予其类似反聚电解质效应的盐响应行为。该设计策略对开发高性能纳米复合水凝胶具有一定的参考价值。

Enhancing the degree of binding of nanoparticles to the gel polymer network in order to improve the heterogeneity between them is extremely critical for improving the mechanical properties of nanocomposite hydrogels.To this end,electrostatic interactions were introduced into the nanocomposite hydrogels to further enhance the mechanical properties of the composite hydrogels.Firstly,the surface modification of silica(SiO_(2))nanoparticles was performed to prepare poly(sodium p-styrene sulfonate)(PSS)-grafted PSS-SiO_(2)nanoparticles,which were then composited with poly(N,N,N-trimethyl-3-(2-methylallylamino)-1-propylammonium chloride(PMPTC))copolymerization-modified poly(acrylamido)(PAM)hydrogel to obtain the PSS-SiO_(2)/P(AM-co-MPTC)nanocomposite hydrogels.The effects of electrostatic interactions between-SO3-of PSS-SiO_(2)nanoparticles and-N+(CH3)3 of PMPTC in PSSSiO_(2)/P(AM-co-MPTC)composite hydrogels on their micro-morphology,solubility,rheological and mechanical properties were investigated.The electrostatic interactions between the polyanions on the surface of PSS-SiO_(2)nanoparticles and the polycations of the hydrogel network significantly enhanced the bonding degree between the SiO_(2)nanoparticles and the hydrogel matrix.Compared with the SiO_(2)/P(AMco-MPTC)nanocomposite hydrogel with the addition of pure SiO_(2)nanoparticles,the mechanical properties of the PSS-SiO_(2)/P(AM-co-MPTC)nanocomposite hydrogel with the addition of PSS-SiO_(2)nanoparticles were significantly improved,and the optimal component had a tensile modulus of up to 160.9kPa,a strength of 95.7kPa and a toughness of 31.1kJ/m3,which increased by 176%,297%and 556%,respectively.The as-fabricated hydrogels also exhibited salt-responsive behavior of anti-polyelectrolyte effects.This study shows that the introduction of electrostatic interactions between nanoparticles and the composite gel matrix helps to further enhance the mechanical properties of the composite hydrogels while endowing them with salt-responsive behaviors similar to the inverse polyelectrolyte effect.The design strategy is informative for the development of high-performance nanocomposite358'hydrogels.