Dual-Responsive Bilayer Reactor Capable of Non-Tandem/Tandem Adjustable Catalytic Ability

Abstract

To address the rising challenges in self-controlled tandem processes, a catalytic reactor with two reversely-responsive layers was fabricated, for which the two layers acted as the carriers of two different-type active sites so as to achieve the adjustable catalytic ability. This first layer was a shape-memory copolymer consisting of 2-acrylamido-2-methylpropane sulfonic acid and 1-heptene. Given the “frozen” domains in the copolymer at low temperatures, the channel of the substrate became closed. At middle temperatures, the channel of the substrate became open as a result of the activation of the copolymer. The second layer was a copolymer embedding Ag nanoparticles made of polymeric 2-(trifluoromethyl) acrylic acid and 2-vinylpyridine. This layer showed the “closed” channel at low temperatures due to the electrostatic interactions between the two polymeric components, which inhibited the entry of reactants. At higher temperatures, as the polymeric interactions at this layer were broken, the channel in this layer became open for the reactants. In combination with the contained acidic sites and catalytic Ag nanoparticles sites in the two layers, which were individually responsible for catalytic hydrolysis and reduction, the reactor did not show substantive catalytic ability at low temperatures due to the closed channels in both the two layers. At middle temperatures, the reactor ran with simple hydrolysis due to the open channel in the first layer which contained acidic sites. At higher temperatures, the reactor ran with tandem catalytic processes because of the open channels in the two layers. Hence, the design of the dual-responsive catalytic reactor acquired the non-tandem/tandem self-controlled catalytic ability.