Construction Of Supramolecular Hydrogels Based On Thermoresponsive Pillar[n]arenes And Their Application In Smart Window

Smart window,as an effective energy-saving device,can adjust the transmission of solar light in different wavelength ranges according to various stimulus responses.Owing to the long term trend of energy shortage in future,energy-saving devices like smart windows are particularly indispensable and would play a significant role in reducing energy consumption for their unique property.Although there are many kinds of reported materials for fabricating smart windows,they still have various defects and drawbacks which are not conducive to the practical application.While improving the properties of known materials,it is increasingly urgent for us to find new alternative materials.As a new type of supramolecular macrocyclic molecule,pillararenes have been applied in many fields due to their excellent properties.However,we have not found relevant reports on smart windows.In this thesis,we successfully constructed a supermolecular hydrogel smart window based on warm/cool tone-switchable thermochromic materials.In addition,we further designed a supermolecular nanocomposite hydrogel film for energy-saving smart window.The specific research contents of this dissertation mainly include the following two parts:In the first part,we successfully prepared a dry gel with ferrocene pendants modifying on the polyacrylamide-based polymer networks(Fc-gel).A well-swollen and high transparent hydrogel(Fc-gel·EGP6)was obtained when the Fc-gel was immersed in the aqueous solution of ethylene glycol chain-modified pillar[6]arene(EGP6).Due to the formation of hydrophilic inclusion complexes between EGP6 and ferrocene groups of Fc-gel instead of the original hydrophobic domains formed by physical cross-linking of hydrophobic ferrocene groups,water absorption capacity of the generated Fc-gel·EGP6 hydrogel was significantly improved,which resulted in the drastically swelling property and enhanced transparency of Fc-gel-EGP6 hydrogel than that of the dry Fc-gel.We orthogonally integrated the thermo-responsiveness of ethylene glycol chain-modified pillar[6]arene(EGP6)and the redox-induced reversible color switching between warm and cool tune of ferrocene/ferrocenium groups into a system to achieve the fabrication of warm/cool tone-switchable thermochromic materials with cooperative and non-interfering dual functions.Notably,the obtained bifunctional material for fabricating smart windows can not only regulate the input of solar energy but also can provide a more comfortable in-door environment to improve the feelings and emotions of indoor peopleIn the second part,we successfully prepared a supramolecular nanocomposite hydrogel film is by integrating ethylene glycol-modified pillar[5]arene(EGP5)and antimony-tin oxide(ATO)nanoparticles.Owing to the thermo-responsiveness of EGP5 and plasmonic heating induced by near-infrared(NIR)absorption of ATO,the obtained film exhibits outstanding photo-thermochromic effect,which results in excellent sunlight-induced solar modulation.Meanwhile,the film possesses high repeatability and durability based on the dynamicity and reversibility of EGP5-based host-guest interaction.Therefore,this supramolecular film is further applied in the fabrication of smart window for the investigation on regulating indoor temperature.The result demonstrates that the obtained smart window based on this supramolecular nanocomposite hydrogel film can preferentially trigger its sunlight-induced photo-thermochromic effect to achieve a cool indoor temperature for a more comfortable lifeIn summary,two kinds of supramolecular hydrogel smart windows based on thermoresponsive pillararenes have been successfully constructed in this dissertation,which show excellent practical potential.Notely,smart windows fabricated by pillararenes are reported for the first time,and it also opens up a new research direction for the application of supramolecular chemistry in the future.