The colloid of delaminated layered double hydroxides(LDHs), a new LDH-based catalyst, is described. The semi-heterogeneous delaminated colloidal MgPdA1-LDH, in which the total surface of catalytic site-bearing lamella...The colloid of delaminated layered double hydroxides(LDHs), a new LDH-based catalyst, is described. The semi-heterogeneous delaminated colloidal MgPdA1-LDH, in which the total surface of catalytic site-bearing lamellae was rendered accessible for chemical reactivity, showed excellent catalysis toward Suzuki reaction. The turnover frequency of this catalyst for Suzuki reaction between bromobenzene and phenylboronic acid is about 8000 h^-1.展开更多
he electrical property,stability and rheological property of mixed metal hydroxide(MMH)-clay aqueous suspensions were studied via determining elec- trophoretic mobilities,heterocoagulation and rheological parameters....he electrical property,stability and rheological property of mixed metal hydroxide(MMH)-clay aqueous suspensions were studied via determining elec- trophoretic mobilities,heterocoagulation and rheological parameters. The suspen- sions of MMH-Na-montmorillonite and MMH-Kaolinite may be transformed from negatively charged systems into positively charged systems through changing the ratio of MMH to clav. The increase of MMH content makes the stability of dilute MMH-clay suspensions decreased in negatively chrged systems and increased in positively chrged systems. The complete coagulations at near neutral systems oc- curs. In the concentrated MMH-clay suspension,the steric network structures may be formed between MMH and clay particles,which cause the apparent viscosity(AV)and Bingham yield point(YP) of the suspentqion to increase. There is a suit- able ratio of MMH to clay at which the AV and YP of the suspension attain a maximum value,which in agreement with “bridging theory”of polymer flocculation.展开更多
在基础实验教学中,氢氧化铁胶体的制备及电泳实验,失败率居高不下。论文探讨了导致实验失败的可能因素,改进了胶体的纯化条件,优化了FeCl_3的用量,提高实验成功率。0.3或0.5 g FeCl_3固体制备约200 mL Fe(OH)_3胶体,在磁力搅拌下,用购...在基础实验教学中,氢氧化铁胶体的制备及电泳实验,失败率居高不下。论文探讨了导致实验失败的可能因素,改进了胶体的纯化条件,优化了FeCl_3的用量,提高实验成功率。0.3或0.5 g FeCl_3固体制备约200 mL Fe(OH)_3胶体,在磁力搅拌下,用购买的透析袋装130 mL胶体,50℃的蒸馏水透析,10 min换水,透析5次。透析后的胶体电泳现象明显,界面清晰,计算的ζ值与文献值更接近。展开更多
基金Supported by the National Natural Science Foundation of China(No.20476092)the Science Foundation of Taizhou University, China(No.09ZD12)
文摘The colloid of delaminated layered double hydroxides(LDHs), a new LDH-based catalyst, is described. The semi-heterogeneous delaminated colloidal MgPdA1-LDH, in which the total surface of catalytic site-bearing lamellae was rendered accessible for chemical reactivity, showed excellent catalysis toward Suzuki reaction. The turnover frequency of this catalyst for Suzuki reaction between bromobenzene and phenylboronic acid is about 8000 h^-1.
文摘he electrical property,stability and rheological property of mixed metal hydroxide(MMH)-clay aqueous suspensions were studied via determining elec- trophoretic mobilities,heterocoagulation and rheological parameters. The suspen- sions of MMH-Na-montmorillonite and MMH-Kaolinite may be transformed from negatively charged systems into positively charged systems through changing the ratio of MMH to clav. The increase of MMH content makes the stability of dilute MMH-clay suspensions decreased in negatively chrged systems and increased in positively chrged systems. The complete coagulations at near neutral systems oc- curs. In the concentrated MMH-clay suspension,the steric network structures may be formed between MMH and clay particles,which cause the apparent viscosity(AV)and Bingham yield point(YP) of the suspentqion to increase. There is a suit- able ratio of MMH to clay at which the AV and YP of the suspension attain a maximum value,which in agreement with “bridging theory”of polymer flocculation.
文摘在基础实验教学中,氢氧化铁胶体的制备及电泳实验,失败率居高不下。论文探讨了导致实验失败的可能因素,改进了胶体的纯化条件,优化了FeCl_3的用量,提高实验成功率。0.3或0.5 g FeCl_3固体制备约200 mL Fe(OH)_3胶体,在磁力搅拌下,用购买的透析袋装130 mL胶体,50℃的蒸馏水透析,10 min换水,透析5次。透析后的胶体电泳现象明显,界面清晰,计算的ζ值与文献值更接近。
