Papers by Keyword: Modified Clay

Abstract: This study considered the effect of modified and unmodified bentonite clay on the thermal properties of films based on cassava starch. The bentonite clay was modified in the presence of cetyl trimethyl ammonium bromide (CTAB). The attainment of exfoliated or intercalated nanocomposite was characterized by X-ray diffraction (XRD) and Fourier transform by infrared radiation (FTIR). In XRD, it was verified that the cassava starch dispersed the modified clay in an exfoliated way and unmodified clay in an intercalated way. In the FTIR it was characterized that the cassava starch interacted more with the modified bentonite clay compared to unmodified. Finally, thermogravimetric curves showed the thermal property of the starch films concluding that the modified clay was the reinforcing material that contributed the most to the thermal stability of the cassava starch film, retarding its decomposition point, around 35oC , in relation to the pure starch film.

Abstract: In this study, was investigated the optimization of the factors that significantly influenced the mechanical property improvement of cassava starch nanocomposites through complete factorial design 23. The factors to be analyzed were cassava starch (A), glycerol (B) and modified clay (C) contents. The clay had its surface modified by anion exchange in the presence of a quaternary ammonium salt. The factorial analysis suggested a regression model capable of predicting the optimal mechanical property of the cassava starch biofilm from the maximization of the elastic modulus. The reliability of the regression model was tested by the correlation established with the experimental data through the following statistical analyzes: Pareto graph and response surface. The response surface showed the best combination of factor configurations to achieve the best response and SEM analysis in thermoplastic cassava starch biofilms in both the best and the worst elasticity conditions was performed to visualize the standard of the structure of the biopolymeric matrix in both conditions. The sequence of the degree of statistical significance on the elastic modulus in relation to the effects investigated is therefore C> B> A> BC> AC.

Abstract: In this study, three kinds of natural clay minerals (kaolin clay, montmorillonite and diatomaceous earth) were used to treat the raw water containing humic acid (HA) by adsorption/sedimentation. The results indicated that natural kaolin clay had no obvious effect on removing HA in water. Using chitosan to modify montmorillonite and diatomaceous earth, the removal effect of the modified diatomaceous earth for HA was better than modified montmorillonite, and the optimal ratio between chitosan and diatomaceous earth was 1:30. Compared with natural diatomaceous earth, the modified clay had better adsorption property for HA at the same dosage. Using modified diatomaceous earth, the maximal removing rates for TOC and turbidity could respectively reach 85.9% and 64.6% with 60 mg/L dosage and 50 min.

Abstract: The modified clay have excellent adsorption performance. This paper discussed the adsorbent dosage, pH, temperature, adsorption equilibrium time and so on the influence of factors on the adsorbent adsorption performance, the results show that the microbial fermentation of rice bran to Cd²⁺ has good adsorption effect. The best adsorption conditions for: dosage of microbial fermentation of rice bran 18 g/L, temperature 30 °C, pH = 3.8, Cd2 + mass concentration is lower than 50 mg/L, the adsorption equilibrium time 30 min, adsorption rate can reach 93.5%, and its application foreground is prospected in wastewater treatment.

Abstract: To develop a new industrial briquette composite binder, response surface methodology was used to arrange experiments, with modified peat(MP），mixed wastes(WS)，modified clay 2(C2) and clay 1(C1) as raw materials. The experimental data was firstly processed utilizing the method of multi-factorial total probability formula evaluation. Then based on the regression analysis and model building, the optimum formula was obtained. Finally, the bonding mechanism was analyzed through a systematical study by means of both ESEM and TG-DTA. The results indicated that the briquette prepared according to the optimum formula, namely 4.4% of MP, 6.5% of WS, 2% of C1, 1% of C2, and correlative key parameters of briquetting technics, namely forming water 13%, drying temperature 180°C and drying time 2.5h had excellent performances, which could meet the demand of industrial production in enterprises.

Abstract: In recent years, the problem of contaminated source water is increasingly outstanding with the rapid development of industry，agriculture and population. Especially, the eutrophication of river and lake is severer. The modified clay was studied to remove algae in lake type raw water in which average concentrations of turbidity, TN, TP and Chl-a were 33NTU, 4.002 mg/L, 0.263mg/L and 29.02 mg/m3. The results showed that the average removal efficiency of turbidity, TN, TP and Chl-a were 88.53%、26.61%、87.45% and 87.97% respectively when the dosage of modified clay was 0.8 g/L.

Abstract: This paper shows the importance of the clay surface chemistry in the preparation of nanocomposite materials. An Argentinean montmorillonite was used for preparing two modified clays. The filosilicate was intercalated with a quaternary ammonium salt derived from ε- caprolactam to obtain an organofilic material. The other modification was introduced by mixing the clay with hexadecyl trimethyl ammonium chloride. Thus, the polyamide 6 ability in dispersing clays was applied to prepare composites with the intercalated clays. The polyamide 6/clay dry composites with 3 wt % of filler were prepared by melt processing in a mixer chamber. Composites of polyamide 6/organoclay were characterized by X-ray diffraction, transmission and scanning electron microscopy and thermogravimetry. The barrier properties were determined by cyclohexane pervaporation. The results show that the dispersion and degree of delamination depend on a proper chemical treatment and the clay content influences the polyamide 6 nanocomposites solvent pervaporation resistance.