Functional polymers and networks

我们研究具有有趣结构和性质的聚合物和聚合物网络的形成。例如，我们使用交联单体在选择的溶剂中的沉淀聚合来形成直径为2至18微米的清洁的单分散微球，其通过新聚合物纳米凝胶的持续沉积而胶体稳定。我们正在学习如何使用这种连续的逐层生长过程，在颗粒生长过程中使用热循环以及注入共聚单体来雕刻具有独特结构和组成的层。这导致直接形成具有限定洋葱结构的多层微球。 我们还研究了聚合物网络形成在油-水界面。我们学习了如何使用正确极性的二氧化硅纳米颗粒而不是可溶性表面活性剂来稳定水中的油乳液。我们现在正在使用类似的化学改性纳米颗粒来形成聚合物壳，以加强所得胶囊，并使其适用于控释应用。 最后，我们正在开发反应性聚电解质，在水性条件下自发联合收割机形成交联水凝胶。这些水凝胶的最终用途是用于囊封和免疫隔离被设计为分泌激素如胰岛素的细胞，并因此用作可移植的、基于细胞的糖尿病治疗。在这里，我们正在探索这些新型水凝胶形成剂的基本化学性质，包括交联化学、水解持久性以及易于用增强相容性的改性剂（如聚乙二醇）进行改性。

We study the formation of polymers and polymer networks with interesting structures and properties. For example, we use precipitation polymerization of crosslinking monomers in select solvents to form clean, mono-disperse microspheres of 2 to 18 micrometer diameter, that are colloidally stabilized by the ongoing deposition of new polymer nanogels. We are learning how to use this sequential, layer-by-layer growth process to inscribe layers of unique structure and composition, using thermal cycling as well as injection of co-monomers, during particle growth. This results in direct formation of multi-layered microspheres with defined onion structures. We also study polymer network formation at oil-water interfaces. We learned how to stabilize oil emulsions in water using silica nanoparticles of the correct polarity, instead of soluble surfactants. We now are using similar, chemically modified nanoparticles to form polymeric shells to strengthen the resulting capsules and make them useful for controlled release applications. Finally, we are developing reactive polyelectrolytes that spontaneously combine in aqueous conditions to form crosslinked hydrogels. The ultimate use of these hydrogels is for the encapsulation and immuno-isolation of cells designed to secrete hormones such as insulin, and hence serve as transplantable, cell-based cures for i.e. diabetes. Here, we are are exploring fundamental chemical properties of these novel hydrogel formers, including crosslink chemistry, persistence to hydrolysis, and ease of modification with compatibility-enhancing modifiers such as polyethyleneglycol.