Via several techniques to modify sensitive matrix for inhabiting the leakage of fluorescent indicator, a new stable sensing material for monitoring phosphates has been prepared and applied to the measurement of phosph...Via several techniques to modify sensitive matrix for inhabiting the leakage of fluorescent indicator, a new stable sensing material for monitoring phosphates has been prepared and applied to the measurement of phosphates in artificial seawater. It is based on the reaction of PO 3- 4 with Al(Ⅲ) Morin that leads to the fluorescence quenching of the composite matrix. At pH value 4 0 and the salinity value 25 0, the response time of output signal having reached the steady state is less than 300 seconds. Its calibration graph is gained in the range of H 2PO - 4 mass concentration from 1 50 to 7 00 μg/mL with the limit of detection(3 σ/K ) 0 02 μg/mL. When it was used to measure phosphates in artificial seawater, the recovery ranged from 96 78% to 102 09%. Being stored under the proper condition, the membranes maintain sensitive for 90-120 days, and are able to be used for 50-80 times with indicator supplement.展开更多
The reaction of n-C_3H_7OH+HBr=n-C_3H_7Br+H_2O was used to experimentally study a coupled pervaporation (PV)-reaction distillation (RD) process. The results show that polyvinyl alcohol (PVA) is a suitable membrane ...The reaction of n-C_3H_7OH+HBr=n-C_3H_7Br+H_2O was used to experimentally study a coupled pervaporation (PV)-reaction distillation (RD) process. The results show that polyvinyl alcohol (PVA) is a suitable membrane material for water removal. The typical separation properties of PVA polyacrylonitrile (PAN) composite membranes are a highest flux of 780 g/(m 2·h) and a separation factor of 840 for the C_3H_7OH concentration in the original feed of 95% at 90℃ and below 3300 Pa(abs). Reaction distillation produced the n-bromopropane from the distillation column as a ternary azeotropic liquid mixture of C_3H_7OH, H_2O and C_3H_7Br, with a product concentration of about 92%. The coupled PV-RD membrane reactor experiment shows that the BrPr yield can reach 92%, much higher than that for reaction-distillation without pervaporation.展开更多
基金Supported by the Foundation for U niversity Key Teacher by the MOE,Natural Science Foundation of Fujian Provinceof China(No.D9910 0 0 9) and Three Projects of Science and Technology of Fujian Province(No.K990 37) .
文摘Via several techniques to modify sensitive matrix for inhabiting the leakage of fluorescent indicator, a new stable sensing material for monitoring phosphates has been prepared and applied to the measurement of phosphates in artificial seawater. It is based on the reaction of PO 3- 4 with Al(Ⅲ) Morin that leads to the fluorescence quenching of the composite matrix. At pH value 4 0 and the salinity value 25 0, the response time of output signal having reached the steady state is less than 300 seconds. Its calibration graph is gained in the range of H 2PO - 4 mass concentration from 1 50 to 7 00 μg/mL with the limit of detection(3 σ/K ) 0 02 μg/mL. When it was used to measure phosphates in artificial seawater, the recovery ranged from 96 78% to 102 09%. Being stored under the proper condition, the membranes maintain sensitive for 90-120 days, and are able to be used for 50-80 times with indicator supplement.
文摘The reaction of n-C_3H_7OH+HBr=n-C_3H_7Br+H_2O was used to experimentally study a coupled pervaporation (PV)-reaction distillation (RD) process. The results show that polyvinyl alcohol (PVA) is a suitable membrane material for water removal. The typical separation properties of PVA polyacrylonitrile (PAN) composite membranes are a highest flux of 780 g/(m 2·h) and a separation factor of 840 for the C_3H_7OH concentration in the original feed of 95% at 90℃ and below 3300 Pa(abs). Reaction distillation produced the n-bromopropane from the distillation column as a ternary azeotropic liquid mixture of C_3H_7OH, H_2O and C_3H_7Br, with a product concentration of about 92%. The coupled PV-RD membrane reactor experiment shows that the BrPr yield can reach 92%, much higher than that for reaction-distillation without pervaporation.
