Design Of Nature-inspired Functional Polymer Reactors And Study Of Functional Catalysis

Since the concept of catalyst was proposed in the 19 th century,the development process of catalyst has been closely related to the development of chemical industry.With the rapid development of chemical industrial processes,the rise of efficient catalysts has been promoted.In the 21 st century,the modern chemical industry has entered a period of rapid development,and the multi-component,multi-step,refined and complex chemical reactions involved are becoming more and more common.A variety of catalysts have been developed and designed by researchers to meet the needs of society.Among them,polymer materials have the advantages of light weight,easy control of composition and structure,and show strong design adaptability in specific applications,so polymer reactors wrapped with catalytic active sites in smart polymers are one of the hot research topics in recent years.In this paper,three polymer reactors were designed for different situations,inspired by nature’s biology,in order to meet the different requirements of catalysts for complex chemical processes involving multi-component and multi-step processes in practical applications.First,the development of selective/non-selective reactors for specific application needs,which can perform selective catalysis in some situations,but non-selective catalytic behavior in others.In the first part of this work,the polymer reactor with recognition-non-recognition switching catalysis was prepared by constructing molecularly imprinted structures in polymers containing acid sites and long chains structures and combining them with metal nanoparticle active sites precisely.Because the reactor possesses both acidic sites and metal nanoparticles,it possesses the ability to catalyze the hydrolysis-reduction multi-step reaction of substrate molecules.In addition,the polymer reactor realizes the specific recognition non-recognition switching catalytic process through the reversible switching of "active domain" freezing or flow state.Specifically,the "active domain" is frozen at low temperature,and the imprinted structure provides a channel that can specifically recognize the substrate molecules,realizing the specific recognition and catalysis of the imprinted substrate molecules;at high temperature,the "active domain" flows,the imprinted structure of the imprinted channel is destroyed,all substrate molecules can enter,and the specific recognition catalysis of the substrate molecules cannot be performed.In this way,the switch of recognition/non-recognition catalysis of the polymer reactor is achieved by controlling the temperature.In the second part of this work,a new catalytic reactor with switchable hydrolysis and hydrolysis-reduction processes is developed for multi-step fine chemical reactions to achieve control of the catalytic reaction process.The reaction process controllable polymer reactor was prepared by the design of two temperature-sensitive functional layers and one inert layer.The first layer is a temperature-responsive hydrolysis functional layer that provides acid sites;the second is a temperature-responsive reduction functional layer;the third layer is an inert layer formed by copolymerization of acrylamide and styrene.The polymer reactor can realize the control of multi-step refined catalysis through the control of two temperature layers.Specifically,at low temperatures,the substrate molecules cannot enter the reactor for the reaction;at medium temperatures,the substrate molecules can enter the reactor for the hydrolysis-reduction reaction;at high temperatures,the substrate molecules can enter the reactor for the hydrolysis reaction.In this way,the polymer reactor enables fine catalytic control of multi-step chemical reactions through the precise control of the temperature.In the third part,a dual-function polymer reactor with switchable catalysis for hydrolysis/degradation reactions has been designed to address the complex and variable environment and demanding requirements of the application.The reactor consists of a temperature-responsive hydrolysis layer(containing acidic catalytic sites)and a photocatalytic layer wrapped with cadmium sulfide nanoparticles.The polymer reactor can be controlled by the cooperation of two functional layers,thus meeting the complex and variable requirements of the reaction process and reducing the experimental separation steps.Specifically,when the temperature is lower than the phase transition temperature of temperature-responsive hydrolysis layer,the polymer network channel is closed and the substrate molecules have difficulty accessing the active sites,and the catalytic hydrolysis cannot be carried out;at higher temperatures,the polymer network channel is opened and the substrate molecules access the active sites for catalytic hydrolysis.When there is a need to degrade the reactants in some cases,the photocatalytic layer of the polymer reactor can realize the catalytic degradation of Rhodamine B under the condition of strong light source.Therefore,the polymer reactor can realize the switching catalysis of hydrolysis and degradation reactions by adjusting the temperature and turning on a strong light source.Through the above research work,the recognition/non-recognition switching catalysis in chemical reactions,the control catalysis of multi-step fine chemical reactions processes,and the switchable catalysis of complex chemical reactions have been realized.It also provides some ideas for the design of catalysts required for various complex reactions in the future.