MWCNTs/Cellulose Hydrogels Prepared from NaOH/Urea Aqueous Solution with Improved Mechanical Properties

Yingpu Zhang,Rong Huang,Zhaocheng Ma,Si Peng

doi:10.1155/2015/413497

Abstract

Novel high strength composite hydrogels were designed and synthesized by introducing multiwalled carbon nanotubes (MWCNTs) into cellulose/NaOH/urea aqueous solution and then cross-linked by epichlorohydrin. MWCNTs were used to modify the matrix of cellulose. The structure and morphology of the hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, high resolution transmission electron microscopy (HR-TEM), and scanning electron microscopy (SEM). The results from swelling testing revealed that the equilibrium swelling ratio of hydrogels decreased with the increment of MWCNTs content. Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) results demonstrated that the introduction of MWCNT into cellulose hydrogel networks remarkably improved both thermal and mechanical properties of the composite hydrogels. The preparation of MWCNTs modifiedcellulose-based composites with improved mechanical properties was the first important step towards the development of advanced functional materials.

Highlights

Hydrogels, because of their excellent hydrophilic properties, biocompatibilities, permeability, and high swelling ratio [1,2,3], have attracted considerable interest from the industry and scientific community
Though some researchers have centered a considerable attention on the synthesis of cellulose-based hydrogels [5] and achieved encouraging breakthrough [9], few have reported on the fabrication of cellulose hydrogels directly from unsubstituted cellulose due to the insolubility of cellulose in aqueous solutions and in most organic solvents resulted from its large proportion of intra- and intermolecular hydrogen bonds
It could be seen that all samples had black sections with enhanced interpenetrating multiwalled carbon nanotubes (MWCNTs) concentration, and these black sections are homogenously dispersed throughout the entire Gels 1–5 hydrogels

Summary

Introduction

Because of their excellent hydrophilic properties, biocompatibilities, permeability, and high swelling ratio [1,2,3], have attracted considerable interest from the industry and scientific community They have been widely applied in food, cosmetics, and biomedical field especially in drug delivery [4] and tissue engineering [5]. Nanoparticles especially carbon nanotubes (CNTs) and their composites [11] have earned great attention for the modification of polymers in the field of material science during the last decade [12] They are very effective fillers in terms of high specific surface area (SSA) and excellent mechanical properties, especially toughness [13]. The swelling behavior and mechanical property were evaluated by measuring the equilibrium swelling ratios and compressive modulus, which might open doors for their potential applications in the field of advanced biomaterials

Experimental

Results and Discussion

Conclusions