Polyacrylonitrile-b-poly(butyl acrylate) Block Copolymers as Precursors to Mesoporous Nitrogen-Doped Carbons: Synthesis and Nanostructure

Abstract

A series of polyacrylonitrile-block-poly(butyl acrylate) (PAN-b-PBA) copolymers were prepared by supplemental activator reducing agent atom transfer radical polymerization (SARA ATRP). These copolymers were then used as precursors to pyrolytic nanostructured carbons with the PAN block serving as a nitrogen-rich carbon precursors and the PBA block acting as a sacrificial porogen. The study revealed that while the size of mesopores can be controlled by the size of the porogenic block, the connectivity of pores diminishes with the decrease of the overall molecular weight of the precursor. This partial loss of mesopore connectivity was attributed to the weaker phase segregation between the blocks of shorter lengths inferred from the shape of small-angle X-ray scattering profiles and from the crystallinity of polyacrylonitrile phase.

Copolymer‐Derived N/B Co‐Doped Nanocarbons with Controlled Porosity and Highly Active Surface

“…(b)]. Such phenomenon can be explained by the weak phase segregation in BCP‐1 caused by too low DP of constituent blocks …”

“…Therefore, the produced nanocarbons showed desired separated N and B doping, enhancing the overall catalytic activity in ORR and capacitances in supercapacitors. This new method not only produces NBCs with outstanding porosity control and highly active surface, but also extends the current copolymer‐templated N‐enriched nanocarbon technique from N mono‐doping to N/B co‐doping …”

Catalytic Halogen Exchange in Supplementary Activator and Reducing Agent Atom Transfer Radical Polymerization for the Synthesis of Block Copolymers

“…A wide variety of monomers, from methyl acrylate (MA) to vinyl chloride (VC), have been polymerized by SARA ATRP. [ 32–42 ]…”

“…Additionally, it allowed reducing the copper load to <50 ppm versus monomer, which is of crucial importance for copolymer‐templated nitrogen‐doped nanocarbons where residual metal may mask the source of catalytic activity in N‐doped carbons. [ 35 ]…”

Photo‐mediated metal free atom transfer radical polymerization of acrylamide in water

“…After decades of development, ATRP has gotten significant progresses. These progresses include reverse ATRP, activators generated by electron transfer ATRP, initiators for continuous activator regeneration ATRP, activators regenerated by electron transfer ATRP, supplemental activators and reducing agent ATRP, photochemically mediated ATRP, and electrochemically mediated ATRP . Among them, photochemically mediated ATRP has become an attractive technique due to mild conditions and suitable for a number of monomers.…”