Liu R, Saunders B R
Polymer Science and Technology Group, The School of Materials, Materials Building, The University of Manchester, Grosvenor Street, M1 7HS, UK.
J Colloid Interface Sci. 2009 Oct 1;338(1):40-7. doi: 10.1016/j.jcis.2009.05.073. Epub 2009 Jun 6.
In this study we investigate triggered particle capture at substrates containing adsorbed thermally responsive graft copolymers. The copolymers used were PDMA(x)(+)-g-(PNIPAm(n))(y), where DMA(+) is quaternized N,N-dimethylaminoethyl methacrylate and NIPAm is N-isopropylacrylamide. The x and y values originate from the macroinitiator used for copolymer preparation. In this study the copolymers are adsorbed onto two different substrates: quartz microscope slides and microporous, high surface area carbon foam. The substrates were coated with a layer of calcined laponite. The laponite acted as a conditioning layer and promoted strong adsorption of the copolymer. The hydrophobicity of the thermoresponsive surfaces was probed using variable-temperature contact angle measurements. The contact angles generally increased considerably upon increasing the temperature to above the lower critical solution temperature (LCST) of the copolymers. The ability of the thermoresponsive surfaces to capture dispersed particles was investigated using anionic and cationic polystyrene (PS) particles. PDMA(30)(+)-g-(PNIPAm(210))(14) was the most effective copolymer in terms of providing high capture efficiencies of anionic PS particles using temperature as the trigger. The thermoresponsive surfaces strongly held the anionic PS particles even when cooled to below the LCST. The relationships between copolymer structure and particle capture efficiency are discussed. The new approach used here for preparation thermoresponsive surfaces is potentially scalable to high volume applications.
在本研究中，我们研究了在含有吸附的热响应性接枝共聚物的基底上触发的粒子捕获。所使用的共聚物为PDMA(x)(+)-g-(PNIPAm(n))(y)，其中DMA(+)是季铵化的甲基丙烯酸N,N-二甲基氨基乙酯，NIPAm是N-异丙基丙烯酰胺。x和y值源自用于共聚物制备的大分子引发剂。在本研究中，共聚物被吸附到两种不同的基底上：石英显微镜载玻片和微孔、高表面积碳泡沫。基底涂覆有一层煅烧锂皂石。锂皂石作为调节层，促进了共聚物的强吸附。使用可变温度接触角测量来探测热响应表面的疏水性。当温度升高到高于共聚物的低临界溶液温度（LCST）时，接触角通常会显著增加。使用阴离子和阳离子聚苯乙烯（PS）颗粒研究了热响应表面捕获分散颗粒的能力。就以温度为触发因素提供高阴离子PS颗粒捕获效率而言，PDMA(30)(+)-g-(PNIPAm(210))(14)是最有效的共聚物。即使冷却到低于LCST，热响应表面仍能牢固地保持阴离子PS颗粒。讨论了共聚物结构与颗粒捕获效率之间的关系。这里用于制备热响应表面的新方法有可能扩展到大规模应用。
