Preparation Of Silicon/Carbon-based Smart Responsive Imprinted Polymers And The Application In Separation Of Pollutants

Smart responsive molecular imprinted polymers(SR-MIPs), combining the molecular imprinting technique and stimuli responsive mechanism, will be changed in the molecular chain structure, the degree of swelling, surface properties and solubility in response to the external environmental stimuli. These changes cause the alteration of the three-dimensional structure of imprinted sites, resulting in the deletion of specific recognition ability, thereby achieving the responses of SR-MIPs towards template molecules. Thus, based their smart selective recognition, it will be of great importance in building environment-friendly functional materials.In this paper, by combinations of the inherent advantages of molecular imprinting technology, light-initiated polymerization, living/controlled radical polymerization and stimuli responsive mechanism, the smart responsive surface imprinted polymers had been prepared, which possessed the better morphology and higher performance. The synthesized materials were characterized, and their adsorption property and the specific recognition ability were discussed. Moreover, the intelligent controllable recognition mechanism of SR-MIPs were further studied. The present work mainly provided the deep analysis and useful insights concerning the feasibility of using stimuli-response imprinted materials in intelligent separation system. The main research contents and results were as follows:(1) A novel core-shell ion imprinted polymers(P-IIPs) based on silica nanoparticles had been synthesized by photoinitiated polymerization at ambient temperature. Subsequently, PIIPs were characterized and applied for batch adsorption experiments. Compared with the imprinted polymers by thermal-initiated polymerization, P-IIPs exhibited much more homogeneous morphology and a higher performance in adsorption capacity. Moreover, theoretical analysis and experimental results show P-IIPs are well applicable at a roomtemperature environment, which can improve their applicability. P-IIPs were proved to be an effective and promising adsorbent of Co(II) from aqueous solution by fixed-bed column study. The synthesized polymers also possessed an excellent eluting performance and regenerate property. Meantime, the study indicated P-IIPs can provide desirable capability for selective removal Co(II) at practical application at the normal temperature.(2) A novel photo-responsive MIPs(P-MIPs) endowed with a higher adsorption capacity based on mesoporous materials have been prepared by combining the stimuli-responsive mechanism and imprinting technology. The physical property and structure of newly synthesized materials have been characterized, and their photoisomerization properties were studied. P-MIPs exhibited the excellent photo-responsive binding properties towards template molecules(BPA). The adsorption behaviors of BPA onto P-MIPs were line with the Langmuir isotherm model and the pseudo-second-order kinetic model. The smart materials possessed a superior photo-regulated separation property. The template molecules can be easily bound in the recognition sites and go back into the solution under the alternating irradiation. P-MIPs have been successfully applied to photo-controlled separation of BPA in real water sample with good recovery, indicating the great applicability for selectively separating specific analytes from complex samples.(3) A novel temperature-sensitive MIPs(GT-MIP) based on graphene oxide have been prepared via light-initiated RAFT polymerization at room temperature by combining the stimuli responsive mechanism and imprinting technology. The physical property and structure of GT-MIP have been characterized, and their adsorption properties were studied. The results showed that, GT-MIP exhibited the uniform polymer nanospheres in 2D planar structure. The adsorption process of GT-MIP towards p-NP was a chemical adsorption process, and their adsorption behavior was line with the Langmuir isotherm model. The maximum adsorption capacity of GT-MIP was 247.31 mg g-1. GT-MIP possessed the specific recognition ability towards p-NP. The DSC study showed that they have superior temperature-sensitive behaviors, and the LCST is 35.67 °C. The adsorption of p-NP onto GT-MIP at different temperature showed that the recognition ability of GT-MIP towards the substrate could be manipulated by the change of temperature. Through the in-depth analysis of their temperature responsive recognition mechanism, the results indicated that the adsorbed target onto the surface of GTMIP can be eluted or recognized under the control of temperature. Importantly, the temperature responsive recognition ability expanded the potential applications of thermally responsive imprinted materials.