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
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.
