Fabricating highly catalytically active block copolymer/metal nanoparticle microstructures at the liquid/liquid interface

• Published in: Journal of colloid and interface science Vol. 522; pp. 272 - 282
• Main Authors: Diao, Qi, Li, Xiaoyang, Diao, Mengxiao, Lee, Yong-Ill, Liu, Hong-Guo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.07.2018
• Subjects: Block copolymers; Cu nanoparticles; Heterogeneous catalysis; Liquid/liquid interface; Spontaneous emulsification; Heterogeneous catalysis; Spontaneous emulsification; Liquid/liquid interface; Cu nanoparticles; Block copolymers
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2018.03.071

Block copolymer/copper composite microstructure with highly heterogeneous catalytic activity was fabricated successfully at the liquid/liquid interface. [Display omitted] Our previous studies have shown that the metal nanoparticle/polymer composite structures fabricated at the liquid/liquid interface have good reusability but lower catalytic activity for heterogeneous reactions in aqueous solutions. This should be attributed to the poor water wettability and more compact structure of the polymer matrices. Therefore, it should be possible to improve the catalytic activity through designing and fabricating a porous composite structure with good water wettability. A modified liquid/liquid interface adsorption and fabrication method was used. An aqueous solution of copper acetate and a chloroform/DMF mixed solution of PS-b-PAA acted as the two phases. Through spontaneous emulsification, self-assembly of the polymer molecules with Cu2+ ions in the droplets, and adsorption of the formed spherical micelles and nanofibers to the planar liquid/liquid interface, a porous composite microstructure was formed. This structure consisted of nanofiber-connected nanospheres which have a PS core and a PAA corona. Tiny and well-dispersed Cu nanoparticles were embedded in the hydrophilic corona and were adsorbed on the nanofibers surface as well. After physical cross-linking with 1,6-diaminohexane, the composite material exhibited high catalytic activity and good reusability for the reactions in aqueous solutions. For example, the rate constant for the reduction of p-nitroaniline reached 1965 s−1 g−1.