Preparation of Ultrahigh Molecular Weight Polyethylene/Graphene Nanocomposite In situ Polymerization via Spherical and Sandwich Structure Graphene/Sio2 Support

Enqi Su,Anping Huang,Xinjun Hu,Wensheng Gao,Junji Jia,Yongxiao Bai,Bochao Zhu,Caicai Zhang

doi:10.1186/s11671-018-2515-4

Enqi Su, Anping Huang + Show 6 more

Open Access

https://doi.org/10.1186/s11671-018-2515-4

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Abstract

Reduced graphene oxide/SiO2 (RGO/SiO2) serving as a novel spherical support for Ziegler-Natta (Z-N) catalyst is reported. The surface and interior of the support has a porous architecture formed by RGO/SiO2 sandwich structure. The sandwich structure is like a brick wall coated with a graphene layer of concreted as skeleton which could withstand external pressures and endow the structure with higher support stabilities. After loading the Z-N catalyst, the active components anchor on the surface and internal pores of the supports. When the ethylene molecules meet the active centers, the molecular chains grow from the surface and internal catalytic sites in a regular and well-organized way. And the process of the nascent molecular chains filled in the sandwich structure polymerization could ensure the graphene disperse uniformly in the polymer matrix. Compared with traditional methods, the porous spherical graphene support of this strategy has far more advantages and could maintain an intrinsic graphene performance in the nanocomposites.

Highlights

Graphene, a monolayer of carbon atoms which has a tight packing of honeycomb lattice and serves as the basic building block of graphitic materials, has recently become one of the most appealing stars in material science [1]
Morphological changes starting from graphene oxide (GO) to GO-SiO2 were monitored using transmission electron microscopy (TEM)
The decoration of SiO2 in the GO-SiO2 hybrid is revealed by the TEM image of Fig. 1 c, d, and it is clearly seen that the nanoparticles of SiO2 line up together and are wrapped in GO sheets tightly, forming a sandwich structure

Summary

Introduction

A monolayer of carbon atoms which has a tight packing of honeycomb lattice and serves as the basic building block of graphitic materials, has recently become one of the most appealing stars in material science [1]. A unique micron spherical reduced graphene oxide(RGO)/SiO2 nanocomposite as support for Z-N catalyst with a novel 3D porous architecture was synthesized by the self-assembly and spray freeze-drying method.

Results

Conclusion