pH响应型形状记忆复合水凝胶制备及性能研究

Preparation and properties of pH-responsive shape memory composite hydrogels

通过在聚乙烯醇(PVA)网络中引入动态亚胺键,成功制备了具有pH响应性能的形状记忆水凝胶,并对其微观形貌、力学性能和形状记忆性能进行了研究。结果表明,浸泡pH=10的NaOH溶液后,水凝胶内部交联度提高,网络更加致密,其最高拉伸强度和最大断裂伸长率分别可达(68±0.5)kPa和200%,这表明在碱性条件下,可在聚合物网络中成功引入可逆的动态亚胺键。此外,水凝胶具有形状记忆性能,并且随着壳聚糖季铵盐(HACC)与氧化硫酸软骨素(OCS)质量比的降低,水凝胶的形状固定率与形状恢复率都呈上升趋势,且最优形状固定率和形状恢复率均在80%以上。该pH响应型形状记忆水凝胶,凭借高含水率、良好的生物相容性和独特的刺激响应性等特点,在信息储存与解密、航空航天等领域具有良好的应用前景。

Shape memory hydrogel materials with pH-responsive properties were successfully prepared by introducing dynamic imine bonds into the polyvinyl alcohol(PVA)networks,and their microscopic morphology,mechanical properties and shape memory properties were investigated.The results showed that after immersing in sodium hydroxide solution with pH=10,the internal cross-linking degree increased,the network was more dense,and its maximum tensile strength and maximum elongation at break could reach 68(±0.5)kPa and 200%,respectively,which indicated that dynamic reversible imine bonds were successfully introduced into the polymer network under alkaline conditions.In addition,the hydrogel had shape memory properties,and the shape fixation rate and shape recovery rate tended to increase with the decrease of the mass ratio of chitosan quaternary ammonium salt(HACC)to oxidized chondroitin sulfate(OCS).The optimal shape fixation rate and shape recovery rate were all above 80%.This pH-responsive shape memory hydrogel,with its high water content,good biocompatibility and unique stimulus responsiveness,has promising applications in the fields of information storage and decryption,and aerospace engineering.