Mitochondrial structure-inspired high specific surface area polymer microspheres by encapsulating modified graphene oxide nanosheets

Abstract

Inspired by the unique structure characteristic of mitochondria, styrene-butyl acrylate based (P(St-BA)) polymer microspheres encapsulating octadecylamine modified graphene oxide nanosheets (GO-ODA) within their interior were designed and prepared by miniemulsion polymerization without using petroleum based toxic porogens. The structure of the prepared polymer microspheres was similar to mitochondria, while the GO-ODA with wrinkled structure and high specific surface area was similar to the inner membrane of mitochondria. The transmission electron microscopy (TEM) results showed that GO-ODA nanosheets encapsulated in the polymer microspheres were obviously observed after dissolving the polymer microspheres in dichloromethane. The Brunauer-Emmett-Teller (BET) results showed that the specific surface area of the polymer microspheres increased from 18.50 m2/g to 42.80 m2/g via encapsulating 0.5 wt% of GO-ODA. The molecular dynamics simulation results showed that GO-ODA nanosheets not only had good compatibility with the styrene-butyl acrylate based polymer, but also increased the free volume and the specific surface area of the styrene-butyl acrylate based polymer matrix. In addition, the mitochondrial structure-inspired styrene-butyl acrylate based polymer microspheres encapsulating GO-ODA (GO-ODA@P(St-BA)) had excellent adsorption properties for Rhodamine B, and the maximum adsorption capacity was 30.30 mg/g. Overall, the mitochondrial structure-inspired GO-ODA@P(St-BA) polymer microspheres exhibited great advantages in potential applications of adsorption, catalysis, drug delivery, enzyme immobilization and so on.