Li, Weixing

[["dc.bibliographiccitation.issue","47"],["dc.bibliographiccitation.journal","Physical Chemistry, Chemical Physics"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Liu, Zhao"],["dc.contributor.author","Li, Weixing"],["dc.contributor.author","Plog, Andreas"],["dc.contributor.author","Xu, Yeping"],["dc.contributor.author","Buntkowsky, Gerd"],["dc.contributor.author","Gutmann, Torsten"],["dc.contributor.author","Zhang, Kai"],["dc.date.accessioned","2020-05-14T13:30:54Z"],["dc.date.available","2020-05-14T13:30:54Z"],["dc.date.issued","2014"],["dc.description.abstract","Multi-stimuli responsive materials based on cellulose nanocrystals (CNCs), especially using non-conventional stimuli including light, still need more explorations, to fulfill the requirements of complicated application environments. The structure determination of functional groups on the CNC surface constitutes a significant challenge, partially due to their low amounts. In this study, rhodamine spiroamide groups are immobilized onto the surface of CNCs leading to a hybrid compound being responsive to pH-values, heat and UV light. After the treatment with external stimuli, the fluorescent and correlated optical color change can be induced, which refers to a ring opening and closing process. Amine and amide groups in rhodamine spiroamide play the critical role in this switching process. Solid-state NMR spectroscopy coupled with sensitivity-enhanced dynamic nuclear polarization (DNP) was used to measure 13C and 15N in natural abundance, allowing the determination of structural changes during the switching process. It is shown that a temporary bond through an electrostatic interaction could be formed within the confined environment on the CNC surface during the heat treatment. The carboxyl groups on the CNC surface play a pivotal role in stabilizing the open status of rhodamine spiroamide groups."],["dc.identifier.doi","10.1039/c4cp04096a"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/65440"],["dc.language.iso","en"],["dc.title","Multi-responsive cellulose nanocrystal–rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4181"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Cellulose"],["dc.bibliographiccitation.lastpage","4194"],["dc.bibliographiccitation.volume","21"],["dc.contributor.author","Geissler, Andreas"],["dc.contributor.author","Scheid, Daniel"],["dc.contributor.author","Li, Weixing"],["dc.contributor.author","Gallei, Markus"],["dc.contributor.author","Zhang, Kai"],["dc.date.accessioned","2020-05-18T09:59:46Z"],["dc.date.available","2020-05-18T09:59:46Z"],["dc.date.issued","2014"],["dc.description.abstract","In comparison to stimuli-responsive, multi-functional nanoparticles (NPs) from synthetic polymers, such NPs based on sustainable, naturally occurring polysaccharides are still scarce. In the present study, stable stimuli-responsive, fluorescent and magnetic NPs were fabricated using cellulose stearoyl esters (CSEs) consisting of cellulose and stearoyl groups. The multifunctional NPs with the average diameters between 80 and 250 nm were obtained after facile nanoprecipitation using CSE solutions containing Fe3O4-NPs. Using the aqueous solution of fluorescent rhodamine B as precipitant, NPs with rhodamine B on NP surface were obtained. Rhodamine B could be released depending on the temperature. In comparison, stearoylaminoethyl rhodamine B can be encapsulated in CSE-NPs, which renders obtained NPs reversible fluorescence in response to UV illumination and heat treatment."],["dc.identifier.doi","10.1007/s10570-014-0412-2"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/65510"],["dc.language.iso","en"],["dc.title","Facile formation of stimuli-responsive, fluorescent and magnetic nanoparticles based on cellulose stearoyl ester via nanoprecipitation"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","33"],["dc.bibliographiccitation.journal","Journal of Materials Chemistry. A, Materials for Energy and Sustainability"],["dc.bibliographiccitation.volume","2"],["dc.contributor.author","Li, Wei"],["dc.contributor.author","Wang, Wei"],["dc.contributor.author","Yang, Yongbiao"],["dc.contributor.author","Zhang, Kai"],["dc.date.accessioned","2020-05-18T10:10:57Z"],["dc.date.available","2020-05-18T10:10:57Z"],["dc.date.issued","2014"],["dc.description.abstract","In comparison to single-stimuli responsive cellulose derivatives, multi-stimuli and reversibly responsive compounds from cellulose are still scarce. In this report, the fabrication of redox-controllable nanoparticles (NPs) from novel cellulose derivatives containing thiol groups and rhodamine spiroamide showing reversible fluorescence is described. The thiol groups were introduced into cellulose chains after esterification by 3,3′-dithiodipropionic acid and further reductive cleavage of disulfide bonds. Then, rhodamine spiroamide was immobilized via thiol–ene reaction between cellulose thiopropionyl ester and rhodamine B methacrylamide. The obtained cellulose derivative containing rhodamine spiroamide (cellulose-RhBMA) could be transformed into NPs in aqueous medium and dissolved again via redox reactions on thiol groups. At the same time, cellulose-RhBMA exhibited reversible fluorescence that could be switched using pH (protons) or UV-illumination/heating as external stimuli. In total, we demonstrated the fabrication of redox-controllable NPs with reversible fluorescence, and a novel platform for the chemical modification of cellulose via thiol–ene reaction."],["dc.identifier.doi","10.1039/c4ta02126f"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/65517"],["dc.language.iso","en"],["dc.title","Redox-responsive, reversibly fluorescent nanoparticles from sustainable cellulose derivatives"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]