Papers by Author: Xiao Yan Lin

Abstract: The influences of processing parameters on the tensile strength (TS) of KGM/CaCO₃ composite films (KCaCF) were investigated through orthogonal experiment method. Calcium carbonate and KCaCF were characterized, respectively, by XRD, laser diffraction particle size analyzer, zeta potential analyzer and SEM. The results showed that micron-sized calcite CaCO₃ crystals with-16.4 mv of Zeta potential were synthesized. Calcium carbonate dispersion was blended with KGM to fabricate KCaCF. The mass of CaCO₃, KGM and swelling time affected TS of composite films differently, but didnt reach the significant level (p>0.05). The optimal preparation process for KCaCF is that 5.0% (wt) of KGM powder is added into the dispersion with 2.0% (wt) of CaCO₃, swelling for 1.0 hour at 50 °C and pH 8.0 and then poured onto plate and dried at 50 °C for 15 h.

Abstract: The blend films of ungelatinized and gelatinized starch/polyvinyl alcohol (PVA) were prepared by solution casting method. Their morphologies and thermal properties were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A droplet phase was observed in the blends containing ungelatinized starch and a laminated phase was observed in the blends containing gelatinized starch. For both ungelatinized and gelatinized starch/PVA blends the melting temperature (T_m) (210230) of PVA was detected, and the T_m of gelatinized starch/PVA blends was higher than that of the ungelatinized starch/PVA blends. TGA results showed that over the rst 300 the weight loss for ungelatinized starch/PVA blends was higher than that for gelatinized starch/PVA blends, however the gelatinized starch/PVA blends showed the greater weight loss after scanning up to 400. Different morphologies and thermal properties of two types of blends were attributed to the different hydrogen bonding interactions between starch and polyvinyl alcohol.

Abstract: The increasing use of the PE plastic film means increasing problems of the soil environmental destroy. In order to investigate the effect of PE film degradation products on the carbon dioxide content of soil, degradation products of the PE film with different molecular weight were added in three kinds of soil respectively, and corns were cultivated in the soil. FTIR gas checkout equipment was utilized to monitor changes of the carbon dioxide content of the different soil. A Mathematical model was built with the recorded data to depict variation of the carbon dioxide content. The results showed that the CO₂ content is high in the sandy soil with degradation products of PE plastic films (molecular weight of 5000 Da) . It is also high in the clay soil and loam soil with degradation products of PE (molecular weight of 2000 Da). Compared to the control group (LLDPE), it can be found that small molecular weight PE plastic films have a greater effect on the CO₂ content. Thus, it is deduced that small molecular weight PE plastic films are degradable in the soil.

Abstract: The porous composite adsorbent was prepared using directly the glycerol-plasticized poly (butylene succinate)(PBS) and corn starch that were melt blended by a twin screw extruder. The effect of different ratio of PBS to starch on volume stabilization of the composite adsorbent in the water was investigated, and the optimum mixing ratio was 100:25. The starch/PBS particles were treated by α-amylse on the condition of pH 5, the temperature 50. The major objective of this paper is to characterize the morphology in biodegradable PBS/starch blends using scanning electron microscopy. The effect of the dose of enzyme and hydrolysis time on removal efficiency of the composite adsorbent was studied. The results showed that the enzyme-treated starch/PBS particles had good adsorption efficiency for copper () ions compared to the starch/PBS particles. The optimum ratio of the starch to PBS was 100:25 and enzyme treatment condition was 2% (w/w) enzyme dosage (based on dry starch) and 8h hydrolysis time. Therefore the porous composite particles could be used as potential environmentally friendly materials.

Abstract: The extraction of polyethylene residue components in soil was presented in this work, where polyethylene (PE) powder (Mw=5598) was taken as a simulated polyethylene residue, and decalin was as an excellent solvent. The effects of times of reflux extraction, total extraction time and soil type on the extraction ratio were investigated, aimed at finding out the optimum extraction condition. Results show that the optimum extraction ratio achieves up to 90 % (w/w) at 100 after extraction for 20 mins thrice. Meanwhile, the times of reflux extraction has the most significant influence on extraction ratio, followed by the total extraction time. However, soil type has little influence. The FTIR spectra illustrates that the structure of PE is not destroyed during the extraction. However, the molecular weight and molecular weight distribution test show the average molecular weight of PE decreases after the extraction, which is possibly caused by the degradation of PE.

Abstract: Low cost industrial and agricultural by-products are promising materials for water pollution treatment such as removal of heavy metals. This work deals with removal of silver ions from solutions using expanded rice husk (ERH), nature diatomite (ND) and nature bentonite (NB). Firstly the influence of pH value of the solution on adsorption capacity for silver ions was studied, and then the effect of initial silver concentration on adsorbents adsorption capacity was investigated. The silver ions removal percentage increases with initial pH and achieves a maximum value of nearly 94% at pH= 5.0 ± 0.5 for ERH. The maximum adsorption capacity is 18.6 mg/g for ERH.

Abstract: Adsorption performance of aminated lignin (AmL) for nitrobenzene (NB) removal was investigated through batch experiments. The results showed that AmL possessed strong adsorption ability for NB with hydrogen bond interaction. The equilibrium adsorption data were well represented by the Freundlich isotherm model and the saturated adsorption capacity could reach 24.2mg/g. The adsorption process was found to follow pseudo-second-order kinetics. The maximum adsorption of NB on AmL occurred around the neutral pH.

Abstract: After entering the soil, the degradation products of polyethylene film have a series of influences on ecological environment of the soil. The influences of the molecular weight and the cumulative amount of degraded polyethylene, soil type and soil depth burying polyethylene on the concentration of CO₂ in the soil were investigated through the orthogonal test L₉(3⁴) . Collection and testing of CO₂ were conducted by gas collector underground and the infrared detector of the Automatic Monitoring System of Soil. The change of CO₂ in the soil at a growth cycle of maize was detected continuously by online monitor. The experimental data was analyzed using DPS data processing system. The results show that the impact of soil depth burying polyethylene on CO₂ concentration increase with the increase of burying time, and the molecular weight of polyethylene has a decreasing impact on CO₂ concentration with the increase of burying time. In the former period of the maize growth, the CO₂ concentration is higher in the clay than in the sand and loam. But in the later growth stage the CO₂ concentration in the loam are more abundant than other two soils.

Abstract: The calcium carbonate crystallization was controlled by Ca²⁺ concentrations, under the system of lignin solution with concentration of 10 g / L. Its morphology, structure and thermal decomposition were characterized by FT-IR, SEM, XRD and TG. Results showed that in lignin solution system, concentration of Ca²⁺ had significant effects on the crystallized morphology, orientation and crystallinity of calcium carbonate. Calcium carbonate crystal under low Ca²⁺ concentration had more uniform size while under high Ca²⁺ concentration which tended to form various sizes with more complete crystallization. The calcium carbonate crystals were all calcite calcium carbonate, which formed under different Ca²⁺ concentrations.

Abstract: The influences of preparing conditions on mechanical properties of the white mud (WM) / Konjac glucomannan (KGM) composite film (MKG) were investigated by orthogonal experiments. Zeta potential analysis and DSC were used to characterize the properties of WM and MKG. The results show that the mechanical properties of MKG films can be enhanced through proper modification. Optimized processing parameters of MKG film are described as following: the ratio of KGM, WM, benzoic acid, sodium dodecyl benzene sulfonate(LAS) and stearic acid was 100:14:2:0.24:0.14. 1.00 (wt) % of KGM powder was swelled in deionized water with WM modified by stearic acid, benzoic acid and LAS, stirred for 1.5 hour at 60°C and then paved on plate and dried at 40°C for 15 h to form the MKG film.