In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were p...In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were prepared using CNCs as efficient stabilizers without any additional surfactant. The microspheres were successfully fabricated after volatilization of the solvent. What's more,the size of microspheres could be controlled by fabrication parameters.展开更多
In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric a...In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric analysis,and energy-dispersive X-ray spectroscopy revealed that an Anderson-type POM,(NH4)4[CuMo6O18(OH)6]·5H2O was successfully immobilized on the sponge based on electrostatic interactions.Morphological analysis indicated that the POM-loaded sponge retained its porous structure and that the POM was homogeneously distributed on the sponge walls.The POM-loaded sponge exhibited excellent mechanical properties by recovering 79.9%of its original thickness following a 60%compression strain.The POM-loaded sponge was found to effectively catalyze the hydroboration of phenylacetylenes,yielding excellent conversion and regioselectivity of up to 96%and 99%,respectively.Its catalytic activity remained unchanged after five reuse cycles.These findings represent a scalable strategy for immobilizing POMs on porous supports.展开更多
Polymer-based thermally conductive composites have attracted tremendous interest in thermal management of electronics.However,it remains challenging to achieve high thermal conductivity partly because the difficulty t...Polymer-based thermally conductive composites have attracted tremendous interest in thermal management of electronics.However,it remains challenging to achieve high thermal conductivity partly because the difficulty to obtain favorable distribution and orientation of conductive fillers within the polymer matrix.Herein,networked boron nitride(BN)conductive pathway was realized within the poly(lactic acid)(PLA)matrix,via regenerated cellulose(RC)-assisted assembly of BN on Pickering emulsion interface based on the noncovalent interaction,followed by solvent evaporation and hot-compressing.The strong noncovalent interactions between BN and RC were found critical to enhance the wettability and stability of BN in aqueous media with a lowest mass ratio of 1:40 of RC and BN.The obtained PLA/BN composites feature a thermal conductivity of 1.06 W/(m K)at 28.4 wt%BN loading,representing an enhancement of 430%comparing to neat PLA,and the crystallinity of the composites could increase significantly from11.7%(neat PLA)to 43.7%.This simple,environmentally friendly and effective strategy could be easily extended for effective construction of thermally conductive composites.展开更多
The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethy...The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethylaminoethyl methacrylate)-b-poly(benzyl methacrylate)(PDMA-b-PBzMA)diblock copolymer spherical nanoparticles were synthesized via reversible addition-frag-mentation chain transfer(RAFT)mediated PISA.These diblock copolymer nanoparticles are with nearly the same hydrodynamic size and solvophobic chain length,but with different solvophilic chain length.We used these nanoparticles to stabilize the oil-in-water Pickering emulsion.We find that the stability of Pickering emulsion increases with the length of solvophilic chain of the nanoparticles.Moreover,the droplet size of the Pickering emulsion can be tailored by varying the oil/water ratio and concentration of nanoparticles.展开更多
基金National Key Technology R&D Program of China(No.2014BAC13B02)National Natural Science Foundation of China(No.51403035)+1 种基金Programme of Introducing Talents of Discipline to Universities,China(No.105-07-005735)the Fundamental Research Funds for the Central Universities,China(No.15D110510)
文摘In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were prepared using CNCs as efficient stabilizers without any additional surfactant. The microspheres were successfully fabricated after volatilization of the solvent. What's more,the size of microspheres could be controlled by fabrication parameters.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.2232018A3-04,No.2232018-02,and No.2232018G-043)the Program of Introducing Talents of Discipline to Universities(No.105-07-005735)
文摘In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric analysis,and energy-dispersive X-ray spectroscopy revealed that an Anderson-type POM,(NH4)4[CuMo6O18(OH)6]·5H2O was successfully immobilized on the sponge based on electrostatic interactions.Morphological analysis indicated that the POM-loaded sponge retained its porous structure and that the POM was homogeneously distributed on the sponge walls.The POM-loaded sponge exhibited excellent mechanical properties by recovering 79.9%of its original thickness following a 60%compression strain.The POM-loaded sponge was found to effectively catalyze the hydroboration of phenylacetylenes,yielding excellent conversion and regioselectivity of up to 96%and 99%,respectively.Its catalytic activity remained unchanged after five reuse cycles.These findings represent a scalable strategy for immobilizing POMs on porous supports.
基金supported by the One Belt and One Road Innovative Talent Exchange Program for Foreign Experts[Grant No.DL20200009005]the Fundamental Research Funds for the Central Universities[Grant No.2232021G-02]Fundamental Research Funds for the Central Universities[Grant No.2232020G-04]。
文摘Polymer-based thermally conductive composites have attracted tremendous interest in thermal management of electronics.However,it remains challenging to achieve high thermal conductivity partly because the difficulty to obtain favorable distribution and orientation of conductive fillers within the polymer matrix.Herein,networked boron nitride(BN)conductive pathway was realized within the poly(lactic acid)(PLA)matrix,via regenerated cellulose(RC)-assisted assembly of BN on Pickering emulsion interface based on the noncovalent interaction,followed by solvent evaporation and hot-compressing.The strong noncovalent interactions between BN and RC were found critical to enhance the wettability and stability of BN in aqueous media with a lowest mass ratio of 1:40 of RC and BN.The obtained PLA/BN composites feature a thermal conductivity of 1.06 W/(m K)at 28.4 wt%BN loading,representing an enhancement of 430%comparing to neat PLA,and the crystallinity of the composites could increase significantly from11.7%(neat PLA)to 43.7%.This simple,environmentally friendly and effective strategy could be easily extended for effective construction of thermally conductive composites.
基金This work was supported by the National Natural Science Foundation of China(Nos.21871162 and 22071131)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(No.KF2009).
文摘The morphology of polymeric nanoparticles prepared by polymerization-induced self-assembly(PISA)is depended on the degree of polymerization of the solvophilic and solvophobic blocks.Herein,a series of poly(N,N-dimethylaminoethyl methacrylate)-b-poly(benzyl methacrylate)(PDMA-b-PBzMA)diblock copolymer spherical nanoparticles were synthesized via reversible addition-frag-mentation chain transfer(RAFT)mediated PISA.These diblock copolymer nanoparticles are with nearly the same hydrodynamic size and solvophobic chain length,but with different solvophilic chain length.We used these nanoparticles to stabilize the oil-in-water Pickering emulsion.We find that the stability of Pickering emulsion increases with the length of solvophilic chain of the nanoparticles.Moreover,the droplet size of the Pickering emulsion can be tailored by varying the oil/water ratio and concentration of nanoparticles.
