Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee 53211, USA.
J Phys Chem B. 2009 Dec 31;113(52):16501-7. doi: 10.1021/jp907527x.
An original Ag nanoreactor capable of positively temperature-responsive and substrate-selective catalysis was prepared in this study. This nanoreactor was made of Ag nanoparticles encapsulated in a 4-nitrophenol (NP)-imprinted polymer matrix that exhibited a temperature-sensitive interpolymer interaction between poly(acrylamide) (PAAm) and (2-acrylamide-2-methylpropanesulfonic acid) (PAMPS). At relatively low temperatures (such as 20 degrees C), this nanoreactor did not demonstrate significant NP-selective catalysis due to the interpolymer complexation between PAAm and PAMPS, which caused shrinking in the imprinted networks. Conversely, at relatively high temperatures (such as 40 degrees C), this nanoreactor provided significant NP-selective catalysis resulting from the dissociation of the interpolymer complexes between PAAm and PAMPS. Unlike traditional Ag nanoreactors, which lack positively temperature-responsive catalysis or substrate-selective ability, this unique nanoreactor employed both the imprinting of the substrate molecule (i.e., NP) and a temperature-sensitive PAAm/PAMPS network, thereby making positively temperature-responsive, substrate-selective catalysis feasible.
本研究制备了一种具有正温度响应和底物选择性催化能力的新型 Ag 纳米反应器。该纳米反应器由 Ag 纳米颗粒封装在 4-硝基苯酚(NP)印迹聚合物基质中制成,该基质表现出聚丙烯酰胺(PAAm)和(2-丙烯酰胺-2-甲基丙磺酸)(PAMPS)之间的温度敏感的聚合物间相互作用。在相对较低的温度(例如 20°C)下,由于 PAAm 和 PAMPS 之间的聚合物络合,印迹网络收缩,因此纳米反应器没有表现出明显的 NP 选择性催化作用。相反,在相对较高的温度(例如 40°C)下,由于 PAAm 和 PAMPS 之间的聚合物络合物的解离,纳米反应器提供了明显的 NP 选择性催化作用。与缺乏正温度响应催化或底物选择性能力的传统 Ag 纳米反应器不同,这种独特的纳米反应器既采用了底物分子(即 NP)的印迹,又采用了温度敏感的 PAAm/PAMPS 网络,从而实现了正温度响应、底物选择性催化。