Study On The Interaction Between Hyperbranched Poly(Ether Amine)& Organic Guest Molecules And Their Applications

Hyperbranched polymers(HBPs),an important subclass of dendritic macromolecules,have attracted more and more attention.HBPs exhibit distinctive properties compared to linear polymers due to their highly branched topological structures,adequate spatial cavities,numerous terminal functional groups.HBPs can self-assemble into different topologies of nanoobjects and have unique interactions with guest molecules.HBPs can also be used as modifier and additive,thus endowing other materials with specific properties and functions.Water treatment is one of the great challenges in the 21 st century.In addition to solid particles such as sediment,water-soluble pollutants such as dyes,phenols and anilines,which are widely used in industry.These water pollutants can also cause great harm to human health.Therefore,the removal of pollutants in water is a challenge for many scientists.The commonly used methods are as follows: photocatalytic degradation,biodegradation,adsorption,filtration,etc.In order to solve the problems above,we studied the ultrafast photolysis of fluorescein dyes in the presence of polymer nanomicelles,which were formed by the direct dispersion of amphiphilic hyperbranched poly(ether amine)(hPEA)in aqueous solution.The applications of fluorescein dyes/hPEA systems as visible photoinitiators in photocuring coatings and adhesives has also been studied.In order to utilize the interaction between hPEA and guest molecules,hPEA and polyvinylidene fluoride(PVDF)were blended to prepare composite membrane(hPEA@PVDF)with selectivity for phenols and anilines filtration.First,a series of hPEA were prepared through epoxy/amine “click-chemistry”.Due to their amphiphilic properties,they can be dispersed directly into water and self-assembled into micelles.We studied the photolysis process of six fluorescein dyes with similar structures in the presence of hPEA nanomicelles under 450 nm LED radiation and TEOA as the reference.The results show that the hPEA nanomicelles exhibit ultrafast photobleaching properties for all five dyes except Calcein(Cal).The systematic investigation revealed that the stronger interaction between fluorescein dyes and hPEA nanomicelles lead to faster unexpected photolysis behavior.The hPEA nanomicelles can encapsulate fluorescein dyes as a nanoreactor in aqueous solution,thus increasing the concentration of both dyes and amine groups in the microenvironment by several hundred times,which consequently resulted in the fast photolysis of dyes.Owing to the fast generation of free radicals by the photolysis of dyes,fluorescein dyes can be used as a very efficient visible photoinitiator in the photopolymerization in the presence of hPEA nanomicelles.This unexpected ultrafast photolysis not only provides new inspiration for the wastewater treatment of dye,but also provides significant guidance regarding how to design efficient visible photoinitiators for photocuring technology.Then,we developed a novel kind of hPEA@PVDF porous membrane with different hydrophilicity by introducing double bond and carboxyl groups into hPEA through crystallization and diffusion(CCD)method.The more stable composite structure is obtained by thermal crosslinking of double bonds.Through this method,we fabricated the hPEA@PVDF with porous skeleton of PVDF and cross-linked layer of hPEA hydrogel.The modified membrane shows good selective adsorption performance for phenols and anilines in water.The membrane which has not been modified by carboxyl showed better adsorption performance;compounds with poor water solubility are more easily adsorbed by hPEA@PVDF membrane;compounds containing hydroxyl groups can interact with the large number of amines on the surface of hPEA and thus are more likely to be adsorbed.Hydrophobic interaction and interaction between hydroxyl and amino groups might be the primary origin of the adsorption forces for phenols and anilines compounds on hPEA@PVDF membranes.Based on the superhydrophilicity of the carboxyl-modified hPEA,the hPEA@PVDF membrane can also be used for water-oil separation.Since many phenol derivatives are important pharmaceutical intermediates,the modified membranes also provide new methods and possibilities for purification and separation in the production process.