College of Chemistry, Chemical Engineering and Biotechnology Donghua University, Shanghai 201620, People's Republic of China.
College of Chemistry, Chemical Engineering and Biotechnology Donghua University, Shanghai 201620, People's Republic of China; State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Shanghai 201620, People's Republic of China.
Carbohydr Polym. 2015 Dec 10;134:385-9. doi: 10.1016/j.carbpol.2015.08.009. Epub 2015 Aug 11.
Surfactant-free hydroxypropylcellulose (HPC) nanogels were synthesized by using thermo-sensitive HPC as a template to form HPC/PMAA nanoscale complex. The formation mechanism was owing to the interpolymer hydrogen bonding between HPC and PMAA induced phase transition of HPC in aqueous media. The average size of the resulting HPC nanogels ranges from about 98 to 241 nm. It was found that the average size of HPC nanogels changed little with increasing polymerization temperature below 26 °C, whereas it greatly increased above 26 °C. When the concentration of HPC was increased from 0.1 to 0.9 wt.%, the diameter of nanogels decreased firstly and then increased. Besides, an increasing crosslinker BIS concentration led to a reduced size of HPC nanogels, and the nanogels had the narrowest size distribution when its concentration was 0.1 wt.%. In addition to intrinsic thermo-sensitivity, HPC nanogels also display pH-induced phase transition due to pH-responsive PMAA contained in HPC nanogels. Surfactant-free, dual-responsive HPC nanogels would have promising applications in biotechnology and nanomedicine.
无表面活性剂的羟丙基纤维素（HPC）纳米凝胶是通过使用温敏 HPC 作为模板来形成 HPC/PMAA 纳米级复合物来合成的。形成机理是由于 HPC 和 PMAA 之间的聚合物间氢键导致 HPC 在水介质中的相转变。所得 HPC 纳米凝胶的平均粒径范围约为 98 至 241nm。研究发现，聚合温度低于 26°C 时，HPC 纳米凝胶的平均粒径变化不大，而高于 26°C 时则会大大增加。当 HPC 的浓度从 0.1 增加到 0.9wt.%时，纳米凝胶的直径先减小后增大。此外，随着交联剂 BIS 浓度的增加，HPC 纳米凝胶的粒径减小，当浓度为 0.1wt.%时，纳米凝胶的粒径分布最窄。除了固有温敏性外，由于 HPC 纳米凝胶中含有 pH 响应的 PMAA，因此还表现出 pH 诱导的相转变。无表面活性剂的、双响应性的 HPC 纳米凝胶在生物技术和纳米医学中有很有前途的应用。
