微纳米胶囊缓释凝胶的制备与性能评价

Synthesis and Performance Evaluation of Micro-nano Capsule Sustained Release Gel

康传宏 费东涛 孙建芳 龚蔚青 曹丽丽 郭继香

KANG Chuanhong FEI Dongtao SUN Jianfang GONGWeiqing CAO Lili GUO Jixiang

为达到延缓聚合物凝胶成胶时间的目的，以部分水解聚丙烯酰胺、交联剂J1（醋酸铬）和J2（酚醛树脂）、除氧 剂D-异抗坏血酸、疏水性气相纳米二氧化硅为原料制备了一种微纳米缓释凝胶。利用疏水颗粒在水溶液中的自 组装作用将交联剂溶液封装于颗粒胶囊内部后加入聚合物溶液中，通过缓慢释放交联剂来实现延缓成胶时间的 目的。研究了pH值对疏水颗粒封装能力以及疏水颗粒浓度对胶囊热稳定性、凝胶成胶时间、凝胶强度的影响。 研究结果表明，缓释胶囊适用的溶液pH 值范围为2～10，胶囊中疏水纳米二氧化硅颗粒用量为10%时，胶囊在 240 h 后30 ℃下分水率为3.33%，120 ℃下分水率为26.67%，稳定性良好；使用疏水纳米二氧化硅颗粒用量为 10%的胶囊后，凝胶在30 ℃下成胶时间由48 h 延长至486 h，在120 ℃下由1 h 延长至144 h；30 ℃下成胶的凝胶 储能模量G'由43 Pa 增至313 Pa，屈服应力由102 Pa 增至202 Pa。疏水颗粒制备的缓释胶囊具有较好的热稳定 性，不仅能够延缓凝胶的成胶时间，而且能够增加凝胶的强度。

In order to delay the gelation time of polymer gel，a micro-nano sustained-release（MNSR）gel was prepared using partially hydrolyzed polyacrylamide，crosslinking agent J1（chromic acetate）and J2（phenolic resin），D-isoascorbic acid and hydrophobic fumed silica as raw materials. The crosslinking agent solution was encapsulated by the self-assembly of hydrophobic particles in aqueous solution，and then added into a polymer solution，as a result，the purpose of delaying the gelation time was achieved by slowly releasing the crosslinking agent. The influence of pH value on the encapsulation ability of hydrophobic particles and the concentration of hydrophobic particles on the thermal stability of capsules，gelation time and gel strength were studied. Experimental results showed that the pH value of the solution suitable for the sustained-release capsule was 2—10. When the particle concentration in the capsule was 10%，the water separation rate of the capsule was 3.33% at 30 ℃ and 26.67% at 120 ℃ after 240 h. When the capsules with a particle concentration of 10% were used，the gelation time of the gel was extended from 48 h to 486 h at the temperature of 30 ℃，and was extended from 1 h to 144 h at the temperature of 120 ℃. The gel storage modulus G' of the gel before adding the capsule was 43 Pa and yield stress was 102 Pa，while the G' of MNSR gel was 313 Pa and the yield stress was 202 Pa. The sustained-release capsules prepared by hydrophobic particles had better thermal stability，which not only delayed gelation time，but also increased the gel strength.

10.19346/j.cnki.1000-4092.2022.04.007