Both of quaternary ammonium and quaternary phosphonium salts of bis-hydroxyethyl terephthalate （BHET） were successfully synthesized and characterized by fourier transform infrared spectroscopy （FT-IR）. These two k...Both of quaternary ammonium and quaternary phosphonium salts of bis-hydroxyethyl terephthalate （BHET） were successfully synthesized and characterized by fourier transform infrared spectroscopy （FT-IR）. These two kinds of salts were used to intercalate Na-MMT to yield two kinds of respective organo-modified MMTs. Basal spacing and thermal stability were investigated by using X-ray diffraction （XRD） and thermogravimetric analysis （TGA）, respectively. The experimental results show that, as compared with Na-MMT, basal spacings of both of MMTs modified by the quaternary phosphonium salt of BHET （BHETPP） and the quaternary ammonium salt of BHET （BHEA）, increase from 12.4 A to 19.7/k and 31.3 A, respec-tively. Thermal stability of BHETPP-modified MMT is much better than that of BHEA-modified MMT, i e, T otof BHETPP-modified MMT is around 400℃ while Tcmset of BHEA-modified MMT is near 250℃. Therefore, with en-larged basal spacing and excellent thermal stability, BHETPP-modified MMT is a promising organo-modified MMT which may be used to prepare polyethylene terephthalate/MMT nanocomposite with high thermal and mechanical performance.展开更多
Application of the commercial formulation of chlorpyrifos has resulted in considerable environmental contamination. This study was designed to develop environmentally acceptable chlorpyrifos formulation for safe and e...Application of the commercial formulation of chlorpyrifos has resulted in considerable environmental contamination. This study was designed to develop environmentally acceptable chlorpyrifos formulation for safe and effective application. This involved the modification of clay surfaces from hydrophilic to hydrophobic via ion-exchange reaction with organic cations. The resulting organo-clay complexes were tested for adsorption and release of chlorpyrifos. HPLC and FTIR measurements showed considerable adsorption and strong interaction between chlorpyrifos molecules and the organo-clay complexes. Basal spacing results emphasized the formation of suitable micro-pores for chlorpyrifos molecules. HPLC and bioassay techniques confirmed the slow release of chlorpyrifos. Leaching potential showed retention of chlorpyrifos in the top soil. Therefore application of organoclay formulation of chlorpyrifos may reduce their potential environmental contamination and produce safe applications.展开更多
文摘Both of quaternary ammonium and quaternary phosphonium salts of bis-hydroxyethyl terephthalate （BHET） were successfully synthesized and characterized by fourier transform infrared spectroscopy （FT-IR）. These two kinds of salts were used to intercalate Na-MMT to yield two kinds of respective organo-modified MMTs. Basal spacing and thermal stability were investigated by using X-ray diffraction （XRD） and thermogravimetric analysis （TGA）, respectively. The experimental results show that, as compared with Na-MMT, basal spacings of both of MMTs modified by the quaternary phosphonium salt of BHET （BHETPP） and the quaternary ammonium salt of BHET （BHEA）, increase from 12.4 A to 19.7/k and 31.3 A, respec-tively. Thermal stability of BHETPP-modified MMT is much better than that of BHEA-modified MMT, i e, T otof BHETPP-modified MMT is around 400℃ while Tcmset of BHEA-modified MMT is near 250℃. Therefore, with en-larged basal spacing and excellent thermal stability, BHETPP-modified MMT is a promising organo-modified MMT which may be used to prepare polyethylene terephthalate/MMT nanocomposite with high thermal and mechanical performance.
文摘Application of the commercial formulation of chlorpyrifos has resulted in considerable environmental contamination. This study was designed to develop environmentally acceptable chlorpyrifos formulation for safe and effective application. This involved the modification of clay surfaces from hydrophilic to hydrophobic via ion-exchange reaction with organic cations. The resulting organo-clay complexes were tested for adsorption and release of chlorpyrifos. HPLC and FTIR measurements showed considerable adsorption and strong interaction between chlorpyrifos molecules and the organo-clay complexes. Basal spacing results emphasized the formation of suitable micro-pores for chlorpyrifos molecules. HPLC and bioassay techniques confirmed the slow release of chlorpyrifos. Leaching potential showed retention of chlorpyrifos in the top soil. Therefore application of organoclay formulation of chlorpyrifos may reduce their potential environmental contamination and produce safe applications.
