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1.
Chem Commun (Camb) ; 55(66): 9821-9824, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31360953

RESUMO

A new type of organic proton donor for the strong-acid/base-free hydrogen evolution reaction is reported, by taking advantage of the electron deficiency of the boron center of borinic acid and the strong affinity and hydrolysis reaction between borinic acid and water with hydrogen ion formation. The borinic acid proton donor exhibits even higher current density than H2SO4 to promote hydrogen evolution performance in DMF.

2.
Macromol Rapid Commun ; 38(6)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28169485

RESUMO

A simplified one-pot and less harmful method has been introduced for the synthesis of borinic acid monomer. The corresponding borinic acid polymer (PBA) has been prepared by reversible addition-fragmentation chain transfer polymerization. Property investigations confirm the characteristics of PBA as a new type of "smart material" in the field of thermo-responsive polymer. The potential application of PBA in the field of enzymatic biofuel cell has been illustrated with a wide open circuit potential of 0.92 V.


Assuntos
Fontes de Energia Bioelétrica , Ácidos Borínicos/química , Oxirredutases/metabolismo , Polimerização , Polímeros/química , Polímeros/síntese química , Estrutura Molecular , Tamanho da Partícula , Polímeros/metabolismo , Porosidade , Propriedades de Superfície
3.
Macromol Rapid Commun ; 37(21): 1735-1741, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27647653

RESUMO

A one-pot method is introduced for the successful synthesis of narrow-distributed (D = 1.22) vinyl polymer with both ultrahigh molecular weight (UHMW) (M w = 1.31 × 106 g mol-1 ) and micro-/nanomorphology under mild conditions. The method involves the following four stages: homogeneous polymerization, polymerization-induced self-assembly (PISA), PISA and reorganization, and PISA and multiple reorganizations. The key points to the production of UHMW polystyrene are to minimize radical termination by segregating radicals in different nanoreactors and to ensure sufficient chain propagation by promoting further reorganizations of these reactors in situ. This method therefore endows polymeric materials with the outstanding properties of both UHMW and tunable micro-/nanoparticles under mild conditions in one pot.


Assuntos
Nanopartículas/química , Polimerização , Polímeros/química , Polímeros/síntese química , Radicais Livres/química , Peso Molecular , Tamanho da Partícula , Propriedades de Superfície
4.
Soft Matter ; 11(36): 7159-64, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26256052

RESUMO

The thermo-responsive properties of borinic acid polymers were investigated by experimental and molecular dynamics simulation studies. The homopolymer poly(styrylphenyl(tri-iso-propylphenyl)borinic acid) (PBA) exhibits an upper critical solution temperature (UCST) in polar organic solvents that is tunable over a wide temperature range by addition of small amounts of H2O. The UCST of a 1 mg mL(-1) PBA solution in DMSO can be adjusted from 20 to 100 °C by varying the H2O content from ∼0-2.5%, in DMF from 0 to 100 °C (∼3-17% H2O content), and in THF from 0 to 60 °C (∼4-19% H2O). The UCST increases almost linearly from the freezing point of the solvent with higher freezing point to the boiling point of the solvent with the lower boiling point. The mechanistic aspects of this process were investigated by molecular dynamics simulations. The latter indicate rapid and strong hydrogen-bond formation between BOH moieties and H2O molecules, which serve as crosslinkers to form an insoluble network. Our results suggest that borinic acid-containing polymers are promising as new "smart" materials, which display thermo-responsive properties that are tunable over a wide temperature range.


Assuntos
Ácidos Borínicos/química , Poliestirenos/química , Temperatura , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Solventes , Água/química
5.
J Colloid Interface Sci ; 361(1): 400-6, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21641612

RESUMO

The block copolymer brushes grafted from hollow sphere surface via reverse iodine transfer polymerization (RITP) were investigated in this work. A sufficient amount of azo initiator was introduced onto hollow sphere surface firstly. Then the monomer methyl methacrylate (MMA) was polymerized via surface-initiated reverse iodine transfer polymerization (RITP) using azo group modified hollow sphere as initiator. The microstructure of the samples was characterized by FT-IR, (1)H NMR, respectively. Results indicated that the poly(methyl methacrylate) (PMMA) with end functionality of alkyl iodine group had grafted from hollow sphere surface. TEM observations showed that the average diameter of hollow core was central at 1.3-1.4 µm and the average wall thickness increased from 103 nm to 138 nm and 172 nm after grafting polymerization of MMA and Tb complex, respectively. The closely linear plots of molecular weight (M(n)) versus conversion, linear kinetic plots for the free polymer formed in solution and the ability to extend the chains by sequential addition of monomer indicated that the RITP was a controlled process with a "living" characteristic.

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