Xiao Yi Wei

Structure and Thermal Stability of Sugarcane Bagasse Cellulose Regenerated from Dialkylphosphate Ionic Liquids

A phosphate-based ionic liquid, 1-ethyl-3-methylimidazolium diethylphosphate ([EMI[DE), was synthesized and used to dissolve sugarcane bagasse cellulose under microwave radiation. The original and regenerated cellulose were both characterized by X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The results showed that cellulose had a more porous and less crystalline structure after regeneration, whereas chemical composition had no change. Thermal stability of the regenerated cellulose was somewhat lower, corresponding to the decreased crystallinity. In short, the treatment with [EMI[DE led to desirable structural modification on sugarcane bagasse cellulose via physical process. This is of great benefit to the subsequent downstream processes, such as enzymatic hydrolysis and ethanol fermentation.

Homogeneous Grafting of Bagasse Cellulose in Ionic Liquid

A new cellulose graft copolymer was synthesized by the homogeneous graft polymerization in ionic liquid. The methyl methacrylate was successfully grafted onto the bagasse cellulose in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as a homogenous media. The obtained copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR) and Scanning electron microscope (SEM). The results of thermal analysis curves exhibited two separated pyrolysis with cellulose and the grafted pMMA. Moreover, the homogenous reaction media applied can be carried out in completely recycled ionic liquid, and the modified cellulose has a potential value for oil absorbent.

Synthesis and Properties of Superparamagnetic Fe3O4 Nanoparticles by Co-Precipitation Process

Superparamagnetic Fe3O4 nanoparticle with single phase has been synthesized successfully by a co-precipitation process. On the other hand, the effect of additive anhydrous ethanol in synthesis procedure was investigated for the magnetic properties of nanoparticles in this paper. The structure properties of synthetic Fe3O4 particle were measured through XRD, FT-IR and TG-DSC devices. The characteristic peaks of Fe3O4 have been observed to testify Fe3O4 with single phase. The particle size and shape were observed by SEM and TEM measurements. The addition of anhydrous ethanol could enhance the dispersion of Fe3O4 nanoparticles and restrain the agglomeration of nanoparticles. Therefore, the average particle size was about 18.2 nm, smaller than that of Fe3O4 particles prepared without anhydrous ethanol of 24.3 nm. Correspondingly, the saturation magnetization (Ms) of Fe3O4 prepared with and without anhydrous ethanol was determined to be 53.28 emu/g and 65.28 emu/g, respectively, lower than bulk magnetite particles of 90 emu/g. That is because, synthetic Fe3O4 with smaller particle size obtains the higher surface curvature, which could enhance the disordered crystal orientation on the particle surface, so the saturation magnetization was decreased.

An Orthogonal Experiment of Bagasse Cellulose Dissolution in Ionic Liquid by Microwave Heating

In this paper, bagasse cellulose was dissolved in ionic liquid (1-butyl-3-methylimidazolium chloride) by microwave heating. The orthogonal test and variance analysis were applied to obtain the optimum dissolution condition of bagasse in ionic liquid. The effects of microwave power, temperature and the mass fraction of cellulose were examined by an orthogonal experiment designed through the different dissolution time and the yield of regeneration bagasse. Results showed that the optimal dissolution condition for faster dissolution time was 1% of bagasse cellulose in ionic liquid at 140°C, 500W; while, to get the most yield of cellulose, the condition was 2% of bagasse cellulose at 130°C, 500W.

Homogeneous Modification of Sugarcane Bagasse Cellulose with 2-(Dimethylamino)ethylmethacrylate in Ionic Liquid under Microwave Irradiation

Abstract: A cellulose grafted copolymer was synthesized by homogeneous grafting 2-(Dimethylamino)ethylmethacrylate (DMAEMA) onto the sugarcane bagasse cellulose under microwave irradiation. Cellulose was dissolved in 1-butyl-3-methylinidazolium chloride ionic liquid ([Bmim]Cl) to form a homogeneous solution. The grafting polymerization was then initiated by potassium persulfate in the presence of N,Nˊ-methylenebisacrylamide as a crosslinker. Compared with the traditional thermal heating method, microwave irradiation had a drastic reduction of reaction time and an increased grafted efficiency. The characterization of the graft copolymer was confirmed by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), and Thermogravimetric analysis (TGA). Moreover, the homogenous reaction media applied can be carried out in completely recycled ionic liquid, and the grafted cellulose products have a potential application in wastewater anion absorption.

Preparation and Properties of Regenerated Sisal Cellulose from a Homogeneous Solution

The sisal cellulose was dissolved in ILs under optimal conditions of 150°C and 400W. The structure of sisal cellulose was changed from cellulose I to cellulose II, accompanied with the decrease of crystallinity through XRD, FT-IR analysis. According to the result of GPC, molecular weight distribution became more uniformly and narrow. This is because intra-and inter-hydrogen bond existed in cellulose were destroyed during the dissolution process in ILs. And the regenerated cellulose possessed better properties than the former, which could broaden the application fields of natural cellulose.

Structure and Properties of Natural Cellulose Extracted from Pineapple Leaf

Utilization of agriculture waste has been an issue around the world. In this study, the natural cellulose was extracted from pineapple leaf. Under the optimal pretreatment conditions of 25 g/L, 368 K and 6 h, the ratio of obtained cellulose was above 85 wt%. The structure of obtained cellulose at different stage was confirmed by XRD results. Origin cellulose (OC) and pretreated cellulose (PC) belong to be cellulose I, while regenerated cellulose possessed cellulose II structure, attributed to the dissolution of ionic liquid which destroyed the hydrogen bonds between the cellulose molecules. On the other hand, the structure could be explained by the morphology analysis of OC, PC and RC. The porous network structure of RC led to the reduction of ordered crystalline region and the decrease of crystallinity (CrI), which was proved by BET results. However, the dissolution was testified to be a physical process through FTIR analysis, the existence of characteristic absorption peaks of cellulose. The thermal stability was decreased through pretreatment, dissolution processes, corresponding to the decrease of CrI. The disordered amorphous region of RC decides convenient for production and broad applications.

Effect of Pretreatment on the Structure and Properties of Sisal Cellulose

The goal of this article was to develop an optimum process to extract cellulose from sisal fiber and study the influence of pretreatment on the structure and property of sisal fiber. The sisal fiber was treated with 3% HNO3 solution at 120°C for 3h, then treated with 3% sodium hydroxyl solution at 110 °C for 2h which was the optimum refining condition. The percentage of cellulose reached 97.23% after pretreatment by chemical analysis. The morphology analysis and FTIR analysis proved that hemicellulose and lignin were removed from sisal fiber. The result of XRD indicated that the crystallinity of pretreated fiber declined. The pretreated fiber presented higher thermal stability by TGA.

Isolation and Identification of a Cellulolytic Bacterium from the Huguang Maar Lake

In this study, a strain of cellulolytic bacterium named N-6 was isolated from lake Huguang Maar. Phylogenetic analysis based on a partial 16s rDNA sequence showed that the strain was Bacillus cereus. Extracellular cellulase produced by the strain Bacillus.cereus N-6 exhibits optimum activity around pH 8.0 at 50°C and has good pH tolerance in the range of 6-9.

Synthesis of a Cellulose-Magnetic Nanocomposite in Ionic Liquid

Cellulose nanocomposite is one of the most fascinating materials with broad applications. In this work, cellulose-magnetite nanocomposite has been prepared by dispersion of magnetite nanoparticles in a homogenous ionic liquid solution of grafted cellulose. Bagasse cellulose was first grafted with polymethacrylic acid in 1-butyl-3-methylimidazolium, and then fabricated with Fe3O4 nanoparticles during the homogeneous media. The obtained nanocomposite contained high content of iron due to the clelation of the grafted cellulose and Fe3O4 nanoparticles. It also exhibited superparamagnetic behavior with 8.606 emu/g saturation magnetizations. The cellulose-magnetite nanocomposite will be potential for the development of functional cellulose and protective materials for electromagnet radiation or microwaves.