A facile and rapid method to synthesize graphene/layered double hydroxide(LDH)nanohybrids by a microwave technique is demonstrated.The synthesis procedure involves hydrothermal crystallization of Zn–Al LDH at the sam...A facile and rapid method to synthesize graphene/layered double hydroxide(LDH)nanohybrids by a microwave technique is demonstrated.The synthesis procedure involves hydrothermal crystallization of Zn–Al LDH at the same time in situ reduction of graphene oxide(GO)to graphene.The microstructure,composition,and morphology of the resulting graphene/LDH nanohybrids were characterized.The results confirmed the formation of nanohybrids and the reduction of graphene oxide.The growth mechanism of LDH and in situ reduction of GO were discussed.The LDH sheet growth was found to prevent the scrolling of graphene layers in resulting hybrids.The electrochemical properties exhibit superior performance for graphene/Zn–Al LDH hybrids over pristine graphene.The present approach may open a strategy in hybridizing graphene with multimetallic nano-oxides and hydroxides using microwave method.展开更多
In this work,azobenzene-containing polyurethane liquid crystal networks(PULCN(AZO)s)were synthesized using a one-pot strategy to demonstrate excellent two-way free-standing thermo-/photo-responsive shape memory effect...In this work,azobenzene-containing polyurethane liquid crystal networks(PULCN(AZO)s)were synthesized using a one-pot strategy to demonstrate excellent two-way free-standing thermo-/photo-responsive shape memory effects.Based on the step-growth nature of hydroxyls and isocyanates,the architectures of the networks were adjusted by controlling the stoichiometries of chemical materials.A uniform monodomain sample was prepared by external stress relaxation via a reversible addition reaction of a dynamic carbamate bond.Two independent transition temperatures assigned to glass transition temperature/melting temperature and liquid crystal phase transition temperature were employed to thermally trigger triple shape memory effects and two-way autonomous actuation.In addition,taking advantage of the trans-cis photoisomerization of azobenzene,the programmed network showed a reversible bending and unbending shape change upon irradiation by visible light at450 and 550 nm,respectively.Coupling the autonomously thermo-induced contraction/extension actuation and reversible photo-induced bending/unbending behaviors of PULCN(AZO)s in one system will expand their potential applications in emerging multifunctional devices.展开更多
基金‘‘Région Wallonne’’and European Community(FEDER+1 种基金FSE)and F.R.S.-FNRS(Belgium)for financial supportfunded by the Interuniversity Attraction Poles Programme(P7/05)initiated by the Belgian Science Policy Office
文摘A facile and rapid method to synthesize graphene/layered double hydroxide(LDH)nanohybrids by a microwave technique is demonstrated.The synthesis procedure involves hydrothermal crystallization of Zn–Al LDH at the same time in situ reduction of graphene oxide(GO)to graphene.The microstructure,composition,and morphology of the resulting graphene/LDH nanohybrids were characterized.The results confirmed the formation of nanohybrids and the reduction of graphene oxide.The growth mechanism of LDH and in situ reduction of GO were discussed.The LDH sheet growth was found to prevent the scrolling of graphene layers in resulting hybrids.The electrochemical properties exhibit superior performance for graphene/Zn–Al LDH hybrids over pristine graphene.The present approach may open a strategy in hybridizing graphene with multimetallic nano-oxides and hydroxides using microwave method.
基金supported financially by the National Natural Science Foundation of China(51773131 and 51721091)the Fundamental Research Funds for the Central Universities。
文摘In this work,azobenzene-containing polyurethane liquid crystal networks(PULCN(AZO)s)were synthesized using a one-pot strategy to demonstrate excellent two-way free-standing thermo-/photo-responsive shape memory effects.Based on the step-growth nature of hydroxyls and isocyanates,the architectures of the networks were adjusted by controlling the stoichiometries of chemical materials.A uniform monodomain sample was prepared by external stress relaxation via a reversible addition reaction of a dynamic carbamate bond.Two independent transition temperatures assigned to glass transition temperature/melting temperature and liquid crystal phase transition temperature were employed to thermally trigger triple shape memory effects and two-way autonomous actuation.In addition,taking advantage of the trans-cis photoisomerization of azobenzene,the programmed network showed a reversible bending and unbending shape change upon irradiation by visible light at450 and 550 nm,respectively.Coupling the autonomously thermo-induced contraction/extension actuation and reversible photo-induced bending/unbending behaviors of PULCN(AZO)s in one system will expand their potential applications in emerging multifunctional devices.
