Preparation of Monodisperse Poly(N-isopropylacrylamide) Microgel Particles with Homogenous Cross-Link Density Distribution
Preparation of Monodisperse Poly(N-isopropylacrylamide) Microgel Particles with Homogenous Cross-Link Density Distribution
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DOI：
10.1021/la2010387
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发表时间：
2011-06-21
期刊：
影响因子：
3.9
通讯作者：
Varga, Imre
中科院分区：
文献类型：
--
作者：
Acciaro, Roberta;Gilanyi, Tibor;Varga, Imre
在聚合过程中，通过调节单体和交联剂的加入量，制备了交联密度分布均匀的单分散微凝胶胶乳。为了确定合适的单体进料参数，通过HPLC研究颗粒形成的动力学。制备的均匀交联的微凝胶颗粒的溶胀和光学特性进行了比较，通过正常的沉淀聚合方法制备的不均匀交联的微凝胶的性能。颗粒内交联密度的分布对体系的特性有很大的影响。均质颗粒的溶胀度显著高于非均质微凝胶颗粒的溶胀度。此外，在室温下，含有均匀交联的颗粒的pNIPAm胶乳是透明的，而非均匀交联的颗粒在相同的0.1重量%浓度下形成高度浑浊的体系。
Monodisperse microgel latex with homogeneous cross-link density distribution within the particles was prepared by feeding the monomer and cross-linker into the reaction mixture in a regulated way during the polymerization. To determine the appropriate monomer feeding parameters, the kinetics of the particle formation was investigated by HPLC. The swelling and optical characteristics of the prepared homogenously cross-linked microgel particles were compared to the properties of inhomogenously cross-linked microgels prepared by the normal precipitation polymerization method. The distribution of the cross-link density within the particles inserts a great: influence on the characteristics of the system. The degree of swelling of the homogeneous particles is significantly higher than that of the heterogeneous microgel particles. Furthermore, at room temperature the pNIPAm latex containing the homogeneously crosslinked particles is transparent, while the heterogeneously cross-linked particles form a highly turbid system at the same 0.1 wt % concentration.