Layer-by-Layer Assembled Bacterial Cellulose/Graphene Oxide Hydrogels with Extremely Enhanced Mechanical Properties

Honglin Luo,Zhiwei Yang,Jiaojiao Dong,Yizao Wan,Jian Hu,Xinhua Xu,Jie Wang,Wei Li,Fanglian Yao

doi:10.1007/s40820-018-0195-3

Honglin Luo, Zhiwei Yang + Show 7 more

Open Access

https://doi.org/10.1007/s40820-018-0195-3

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Abstract

Uniform dispersion of two-dimensional (2D) graphene materials in polymer matrices remains challenging. In this work, a novel layer-by-layer assembly strategy was developed to prepare a sophisticated nanostructure with highly dispersed 2D graphene oxide in a three-dimensional matrix consisting of one-dimensional bacterial cellulose (BC) nanofibers. This method is a breakthrough, with respect to the conventional static culture method for BC that involves multiple in situ layer-by-layer assembly steps at the interface between previously grown BC and the culture medium. In the as-prepared BC/GO nanocomposites, the GO nanosheets are mechanically bundled and chemically bonded with BC nanofibers via hydrogen bonding, forming an intriguing nanostructure. The sophisticated nanostructure of the BC/GO leads to greatly enhanced mechanical properties compared to those of bare BC. This strategy is versatile, facile, scalable, and can be promising for the development of high-performance BC-based nanocomposite hydrogels.

Highlights

Nano-carbon materials, such as one-dimensional (1D) carbon nanotube (CNT) and two-dimensional (2D) graphene (GE) and graphene oxide (GO), are believed to be promising candidate materials for tissue engineering and regenerative medicine applications owing to their large specific surface area, high porosity, and excellent mechanical properties [1,2,3,4,5,6,7]
The resultant bacterial cellulose (BC)/GO film serves as a new base membrane on which the second BC/GO film grows via biosynthesis
The last step is the removal of the base membrane and purification of the hydrogel, leaving a freestanding BC/GO nanocomposite hydrogel

Summary

Introduction

Nano-carbon materials, such as one-dimensional (1D) carbon nanotube (CNT) and two-dimensional (2D) graphene (GE) and graphene oxide (GO), are believed to be promising candidate materials for tissue engineering and regenerative medicine applications owing to their large specific surface area, high porosity, and excellent mechanical properties [1,2,3,4,5,6,7] Among these carbonaceous nanomaterials, GO is considered a promising material for biological applications owing to its excellent biocompatibility, better dispersibility in water than GE, and abundant surface functional groups [8,9,10,11,12]. Incorporation of GE or CNTs into the inner core of a 3D BC network, by filtration or postimmersion in a solution of GE or CNTs, is challenging because of the lack of large pores ([ 20 lm) in pristine BC [19]

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