Ji Hua Li

Comparison of Four Different Extraction Methods of Oil from Macadamia integrifolia

Four different extraction methods, solvent extraction, ultrasonic wave-assisted extraction, Soxhlet extraction and supercritical CO2 extraction, were used to extract oil from Macadamia integrifolia, which also named Macadamia nut oil. Fatty acid compositions of Macadamia nut oil were analyzed by gas chromatography and mass spectrometry (GC-MS). The results showed the highest extraction rate was 74.63% via Soxhlet extraction, while supercritical CO2 extraction was 70.53%, ultrasonic wave-assisted extraction was 57.19% and Solvent extraction was 50.37%. Six unsaturated fatty acids, including Z-9-Hexadecenoic acid, E-11-Hexadecenoic acid, 9,12-Octadecadienoic acid, 9-Octadecenoic acid, E-9-Octadecenoic acid and 9-eicosenoate, were identified in the oil by GC-MS．The relative extraction rate of unsaturated fatty acids were 36.53%, 44.21%, 60.62%, 56.81%, respectively. Though the extraction rate was the highest via Soxhlet extraction, the relative content of Z-9-Hexadecenoic acid and 9,12-Octadecadienoic acid were both higher extracted by supercritical CO2 extraction than Soxhlet extraction, which were 15.38% and 1.55%,. As supercritical CO2 extraction has no solvent residual problem, it would be the trend of the development inSubscript text the future to extract Macadamia nut oil.

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.

Comparative Analysis of Volatile Compounds between Jackfruit (Artocarpus heterophyllus L.) Peel and its Pulp

In the study, the solid-phase microextraction (SPME) and gas chromatography and mass spectrometry (GC-MS) were used for identifying and analysising the volatile compounds of jackfruit (Artocarpus heterophyllus L.) fresh peel (FE) and fresh pulp (FU). The result showed that it was apparent differences of the species and quantities of volatile compounds between peel and pulp. 2,3-Butanediol, Butyrolactone, 1-Methoxy-2-propyl acetate, Butanoic acid, 3-methyl-, butyl ester, n-Amyl isovalerate, n-Hexadecanoic acid were found in peel and pulp. While compounds, such as Geranylgeraniol, Lanosterol, Pentanoic acid, 3-phenylpropyl ester, Phthalic acid, butyl 3-methylbut-2-en-1-yl ester, Hexadecanoic acid, methyl ester, were only present in the peel. But in the pulp, compounds, like Dibutyl phthalate Phenol, 2,4-bis (1,1-dimethylethyl)- henols were confirmed, which did not be found in the peel. The experimental result also indicated that SPME-GCMS is a simple, rapid, reliable and effective method to analyze the volatile fraction in jackfruit. It may have as profound an impact on analysising the volatile compounds of jackfruit.

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.

Regeneration of Bagasse Cellulose by Ionic Liquid

Bagasse is an abundant agricultural byproduct. The use of bagasse has generated much interest due to its low cost, possibility of environmental protection and use of locally available renewable resources. In this paper, cellulose was dissolved in the ionic liquid （1-butyl-3-methylimidazolium chloride） and regenerated in water. FT-IR and SEM were used to characterize the structure of the original and regenerated cellulose. It was found that the treatment of the original cellulose in the ionic liquid significantly degraded the cellulose and completely destroyed the cellulose crystals. Despite many studies of the chemical modification of cellulose published around the world in this area, only a few have been investigated about the regeneration of sugarcane bagasse. Theoretical basis was established for further research on the application of the regenerated cellulose in material science.

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.

Preparation and Properties of SiO2-P2O5-TiO2 Membrane for Fuel Cell Electrolytes

As the key parts to fuel cells, proton conducting electrolytes decides the performance of fuel cells. SiO2-P2O5-TiO2 based glasses have been prepared by a sol-gel process in this experiment. Through TG、 XRD and SEM analysis, it was found that the membrane was existed in the form of amorphous structure. And most of the pores were in micro-pores of size less than 10μm. By the results of resistance, the conductivities were obtained by calculation. The influence of temperature to conductivity was discussed in detail. It was found that the conductivity was increased with the increased temperature .The membrane showed overall conductivities greater than 10-2S·cm-1 at 2000Hz in the temperature range of 70~140°C.