One-Step Preparation of Uniform Cane-Ball Shaped Water-Swellable Microgels Containing Poly( N -vinyl formamide)
One-Step Preparation of Uniform Cane-Ball Shaped Water-Swellable Microgels Containing Poly( N -vinyl formamide)
复制标题
一步法制备均匀甘蔗球形水溶胀聚(N-乙烯基甲酰胺)微凝胶
DOI：
10.1021/la204606v
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发表时间：
2012
期刊：
影响因子：
3.9
通讯作者：
Thaiboonrod S
中科院分区：
文献类型：
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作者：
Thaiboonrod S
在这项研究中，我们报告了一个新的家庭的核-壳微凝胶的水溶胀性和具有的形态，是可控的颗粒组成的制备。在此，通过非水分散体（NAD）聚合在一个步骤中制备了几乎单分散的核-壳PNVF-xGMA [聚（N-乙烯基甲酰胺-共-甲基丙烯酸缩水甘油酯）]颗粒（其中X为所用GMA的重量分数）。壳富含PGMA，并通过环氧基团（来自GMA）与酰胺基团（来自NVF）的反应交联。颗粒的核心富含PNVF。制备这些新的微凝胶不需要双官能交联单体。颗粒具有显著的“藤球”状形态，具有相互连接的脊，并且这可以通过x的值来控制。粒径在0.8-1.8 μm范围内可调。碱性水解用于将PNVF片段水解成聚（乙烯胺），PVAM。当水解颗粒分散在纯水中时，阳离子核的高溶胀压力导致壳破碎和一些核聚合物的释放。这种情况发生的程度是可以控制的。值得注意的是，富含PGMA的壳可以通过分散在水中然后干燥而与水解颗粒分离。水解的PNVF-0.4GMA颗粒含有带正电荷和带负电荷的区域，并且分散体似乎在低离子强度下表现出电荷补丁聚集。这里用于制备PNVF-xGMA颗粒的新的交联策略应该通常适用于含酰胺的单体，并且可以使得能够制备一系列新的水溶胀性微凝胶。
In this study we report the preparation of a new family of core–shell microgels that are water-swellable and have a morphology that is controllable by particle composition. Here, nearly monodisperse core–shell PNVF-xGMA [poly(N-vinylformamide-co-glycidyl methacrylate)] particles (wherexis the weight fraction of GMA used) were prepared via nonaqueous dispersion (NAD) polymerization in one step. The shells were PGMA-rich and were cross-linked by reaction of epoxide groups (from GMA) with amide groups (from NVF). The core of the particles was PNVF-rich. A bifunctional cross-linking monomer was not required to prepare these new microgels. The particles had a remarkable “cane-ball”-like morphology with interconnected ridges, and this could be controlled by the value forx. The particle size was tunable over the range 0.8–1.8 μm. Alkaline hydrolysis was used to hydrolyze the PNVF segments to poly(vinylamine), PVAM. The high swelling pressure of the cationic cores caused shell fragmentation and release of some of the core polymer when the hydrolyzed particles were dispersed in pure water. The extent to which this occurred was controllable byx. Remarkably, the PGMA-rich shells could be detached from the hydrolyzed particles by dispersion in water followed by drying. The hydrolyzed PNVF-0.4GMA particles contained both positively and negatively charged regions and the dispersions appeared to exhibit charge-patch aggregation at low ionic strengths. The new cross-linking strategy used here to prepare the PNVF-xGMA particles should be generally applicable for amide-containing monomers and may enable the preparation of a range of new water-swellable microgels.