Smart bilayer polymer reactor with cascade/non-cascade switching catalyst characteristics

Abstract

This study is aimed at addressing how to furnish the catalysts with cascade/non-cascade switching catalytic ability. Inspired from the "soft" properties and divisional isolation function in natural biological systems, this objective was accomplished by developing a new class of hydrogel made of two unique functional layers with different temperature responses where each may self-govern coupled process at a specific temperature condition. This hydrogel polymer catalyst showed almost no catalytic activity at relatively low temperatures (< 37℃) as both channels of bilayer hydrogel polymer catalyst were closed. At modest temperatures (between 37℃ and 50℃), the first step of the tandem reaction (the hydrolysis of p-nitrophenyl acetate (NPA)) showed significant reactivity that arises from the relaxing of the weak polymer complexes hydrogel layer. This allowed NPA to gain entrance to the acidic catalytic active center of the hydrogel. At relatively high temperatures (> 50℃), this hydrogel polymer catalyst further showed significant reactivity towards the hydrolysis reaction of NPA and reduction reaction of intermediate product p-nitrophenol (NP). It mainly results from the opening of both weak polymer complexes hydrogel layer and stronger polymer complexes hydrogel layer, allowing entrance to both acidic catalytic active center and metal nanoparticles active center. In this way, this hydrogel polymer catalyst demonstrated a controllable cascade/ non-cascade catalytic ability. This suggested protocol provides the inspiration with struggling tandem catalysts, which allows opportunities to finely switchable tandem processes.

Chemistry, Structures, and Advanced Applications of Nanocomposites from Biorenewable Resources

“…For this purpose, the fuel cells, solar cells, and water divider catalysts (water splitting catalysis) are the most widely used materials. [283][284][285] Secondly, economic, environmentally friendly, practice and highperformance energy storage devices are required. Most of these properties are in renewable energy resources.…”

“…First, energy can be efficiently converted from unlimited sources such as oxygen reduction reaction, solar power, and water to the applied forms such as electricity and fuel. For this purpose, fuel cells, solar cells, and water splitting catalysts are the most widely used materials. − Second, economic, environmentally friendly, practical, and high-performance energy storage devices are required. Most of these properties are in renewable energy resources.…”

Self-switchable polymer reactor with PNIPAM-PAm smart switch capable of tandem/simple catalysis

“…As it is well known, NPA can undergo a tandem catalytic process from hydrolysis to reduction with NP being the hydrolyzed intermediate and 4-aminophenol (AP) the final product [22]. As a result, the tandem catalysis process can be performed sequentially.…”

“…As a result, only the simple hydrolysis reaction is conducted in this condition. In our previous work, we have studied similar smart tandem catalysts with bilayer or three-layer architectures [22,23]. In this work, a novel improved switchable layer was prepared and we further studied the responsive time range, response sensitivity and the repeated catalytic abilities, so as to prepare a novel reactor with higher sensitivity and ability for more stable switchable catalysis.…”

A Trilaminar-Thermosensitive Hydrogel Catalytic Reactor Capable of Single/Tandem Catalytic Switchable Ability

“…Nowadays, functional materials have been studied to design tandem catalytic reactors, including hydrogel [8,9], Metal-Organic Frameworks [10,11] and membranes [12,13] and so on. Thermosensitive hydrogels are known for its technically easy method to prepare smart tandem catalytic reactors.…”