An integrated poly(dimethylsiloxane) (PDMS) microchip with two sharpened stretching has been presented. The sample was directly introduced into the separation channel through the stretching inlet tip without complicat...An integrated poly(dimethylsiloxane) (PDMS) microchip with two sharpened stretching has been presented. The sample was directly introduced into the separation channel through the stretching inlet tip without complicated power switching supplies and without injection cross-channel. Operations of running buffer refreshing or channel cleaning also becomes simple by vacuumed in one end and placed another tip into solution vial. The fabrication method can be easily applied in most analytical laboratories at low cost in the absence of soft lithography and plasma bonding equipments. Characteristics of the chips were tested and it can be used to separate fluorescence labeled molecules.展开更多
A poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for on-line solid phase extraction (SPE) and electrophoresis separation has been developed and evaluated. The SPE microchannel was crossed to the electrophoresis m...A poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for on-line solid phase extraction (SPE) and electrophoresis separation has been developed and evaluated. The SPE microchannel was crossed to the electrophoresis microchannel. All the microfluidic channels were etched on the glass substrate. The magnetic microspheres were coated with hydroxyl-terminated poly-dimethylsiloxane (PDMS-OH) serving as extraction phase,which could be conveniently immobilized into the sample pretreatment channel by magnetic field. The PDMS-OH microspheres were mobilized into and out of the pretreatment channel by injection flow. The 0.1 μmol/L solution of fluorescence isothiocyanate (FITC)-labeled phenylalanine (Phe) was electrically injected into the SPE channel and extracted onto the PDMS-OH microspheres bed. The enriched FITC-labeled Phe was electrically eluted by 9 mmol/L sodium acetate containing 10% acetonitrile and electrically driven into the electrophoresis channel and then separated. The preconcentration factor could reach 87.5 after sufficient extraction. A linear preconcentration curve was obtained with the initial FITC-labeled Phe concentration ranging from 6 nmol/L to 300 nmol/L (R2=0.9922) with 200 s loading time. The detection limit (S/N=3) for the FITC-labeled Phe was 3 nmol/L.展开更多
This paper focuses on the effects of the PSt content of polystyrene (PSt)-poly (dimethylsiloxane) (PDMS) interpenetrateing network (IPN) polymer membranes, on the pervaporation (PV) characteristics during the removal ...This paper focuses on the effects of the PSt content of polystyrene (PSt)-poly (dimethylsiloxane) (PDMS) interpenetrateing network (IPN) polymer membranes, on the pervaporation (PV) characteristics during the removal of benzene from an aqueous solution of dilute benzene. When an aqueous solution of 0.05wt% benzene was permeated through the PSt-PDMS IPN membranes, they showed high benzene/water selectivity. Both the permeability and the benzene/water selectivity of the membranes were enhanced with increasing PSt content in the PSt-PDMS IPN membrane. The physicochemical mechanism of permeation and separation through the PSt-PDMS IPN membranes during PV is also discussed. The best normalized permeation rate, separation factor for benzene selectivity, and PV separation index of the PSt-PDMS IPN membrane were 1.27 × 10-6 kgm (m2hr)-1, 3293, and 41821, respectively. These PV characteristics are discussed from the viewpoint of the chemical and physical structure of the PSt-PDMS IPN membranes.展开更多
以羟基封端的聚二甲基硅氧烷和α-溴代异丁酰溴为原料,制备了双官能度Br-PDMS-Br,并以此为大分子引发剂,CuCl和2,2’-联吡啶为催化剂,通过原子转移自由基聚合制备了聚甲基丙烯酸丁酯-聚二甲基硅氧烷-聚甲基丙烯酸丁酯(PBMA-b-PDMS-b-PB...以羟基封端的聚二甲基硅氧烷和α-溴代异丁酰溴为原料,制备了双官能度Br-PDMS-Br,并以此为大分子引发剂,CuCl和2,2’-联吡啶为催化剂,通过原子转移自由基聚合制备了聚甲基丙烯酸丁酯-聚二甲基硅氧烷-聚甲基丙烯酸丁酯(PBMA-b-PDMS-b-PBMA)三嵌段聚合物。利用傅里叶变换红外光谱仪(FT-IR)、核磁(1 H NMR)、凝胶渗透色谱分析仪(GPC)、热失重分析仪(TGA)、接触角测试仪、扫描电子显微镜(SEM)对三嵌段聚合物的结构及聚合反应进行了表征与测试。结果表明三嵌段聚合物具有较好的热稳定性、疏水性和微相分离。展开更多
A novel silicone-based poly(urea-thiourea)/tannic acid composite(PDMS-P(Ua-TUa)-TA)with excellent mechanical,self-healing and antifouling properties is developed.The multiple dynamic hydrogen bonds formed by thiourea ...A novel silicone-based poly(urea-thiourea)/tannic acid composite(PDMS-P(Ua-TUa)-TA)with excellent mechanical,self-healing and antifouling properties is developed.The multiple dynamic hydrogen bonds formed by thiourea groups,urea groups,and tannic acid(TA)molecules ensured a tough elastomer(ultimate strength:2.47 MPa)with high stretchability(~1000%).TA molecules as partial hydrogen bonding cross-linking sites interacted rapidly with urea and thiourea groups before the migration of polymer chains,resulting in fast and efficient self-healing.Scratches on the film completely disappeared within12 min,and the repair efficiency of strength was up to 98.4%within 3 h under ambient condition.Selfhealing behavior was also evaluated in artificial seawater and the healing efficiency(HE)was 95.1%.Furthermore,TA uniformly dispersed in the polymer matrix provides good antibacterial and anti-diatom properties,as well as strong adhesion to the substrate(~2.2 MPa).Laboratory bioassays against marine bacteria adhesion(~96%,~95%and~93%reduction for P.sp.,E.coli,and S.aureus,respectively)and diatom attachment(~84%reduction)demonstrated an outstanding antifouling property of the PDMSP(Ua-TUa)-TA.This work provides a promising pathway towards the development of high-performance silicone-based coatings for marine anti-biofouling.展开更多
A new chromatographic method is described for the determination of specific refractive index increment（dn/dc）μ at a constant chemical potential,for polymer/mixed solvent systems.In this method the（dn/dc）is obtain...A new chromatographic method is described for the determination of specific refractive index increment（dn/dc）μ at a constant chemical potential,for polymer/mixed solvent systems.In this method the（dn/dc）is obtained by measuring the areas of solvated-polymer peaks when the mixed solvent is used as an eluent.Values of（dn/dc）μ for the poly（dimethylsiloxane）（PDMS）-benzene-methanol system,determined by the proposed method are in good agreement with those determined by the conventional dialysis method.The new approach has the advantages of simplicity,fast speed,and high reproducibility.The experimental results for stearic acid-chloroform-methanol system show that this method can also be applied to nonpolymer/mixed solvent systems for the determination of（dn/dc）μ.展开更多
文摘An integrated poly(dimethylsiloxane) (PDMS) microchip with two sharpened stretching has been presented. The sample was directly introduced into the separation channel through the stretching inlet tip without complicated power switching supplies and without injection cross-channel. Operations of running buffer refreshing or channel cleaning also becomes simple by vacuumed in one end and placed another tip into solution vial. The fabrication method can be easily applied in most analytical laboratories at low cost in the absence of soft lithography and plasma bonding equipments. Characteristics of the chips were tested and it can be used to separate fluorescence labeled molecules.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20605018 & 30772006) the Beijing Natural Science Foundation (Grant No. 2072018)
文摘A poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for on-line solid phase extraction (SPE) and electrophoresis separation has been developed and evaluated. The SPE microchannel was crossed to the electrophoresis microchannel. All the microfluidic channels were etched on the glass substrate. The magnetic microspheres were coated with hydroxyl-terminated poly-dimethylsiloxane (PDMS-OH) serving as extraction phase,which could be conveniently immobilized into the sample pretreatment channel by magnetic field. The PDMS-OH microspheres were mobilized into and out of the pretreatment channel by injection flow. The 0.1 μmol/L solution of fluorescence isothiocyanate (FITC)-labeled phenylalanine (Phe) was electrically injected into the SPE channel and extracted onto the PDMS-OH microspheres bed. The enriched FITC-labeled Phe was electrically eluted by 9 mmol/L sodium acetate containing 10% acetonitrile and electrically driven into the electrophoresis channel and then separated. The preconcentration factor could reach 87.5 after sufficient extraction. A linear preconcentration curve was obtained with the initial FITC-labeled Phe concentration ranging from 6 nmol/L to 300 nmol/L (R2=0.9922) with 200 s loading time. The detection limit (S/N=3) for the FITC-labeled Phe was 3 nmol/L.
文摘This paper focuses on the effects of the PSt content of polystyrene (PSt)-poly (dimethylsiloxane) (PDMS) interpenetrateing network (IPN) polymer membranes, on the pervaporation (PV) characteristics during the removal of benzene from an aqueous solution of dilute benzene. When an aqueous solution of 0.05wt% benzene was permeated through the PSt-PDMS IPN membranes, they showed high benzene/water selectivity. Both the permeability and the benzene/water selectivity of the membranes were enhanced with increasing PSt content in the PSt-PDMS IPN membrane. The physicochemical mechanism of permeation and separation through the PSt-PDMS IPN membranes during PV is also discussed. The best normalized permeation rate, separation factor for benzene selectivity, and PV separation index of the PSt-PDMS IPN membrane were 1.27 × 10-6 kgm (m2hr)-1, 3293, and 41821, respectively. These PV characteristics are discussed from the viewpoint of the chemical and physical structure of the PSt-PDMS IPN membranes.
文摘以羟基封端的聚二甲基硅氧烷和α-溴代异丁酰溴为原料,制备了双官能度Br-PDMS-Br,并以此为大分子引发剂,CuCl和2,2’-联吡啶为催化剂,通过原子转移自由基聚合制备了聚甲基丙烯酸丁酯-聚二甲基硅氧烷-聚甲基丙烯酸丁酯(PBMA-b-PDMS-b-PBMA)三嵌段聚合物。利用傅里叶变换红外光谱仪(FT-IR)、核磁(1 H NMR)、凝胶渗透色谱分析仪(GPC)、热失重分析仪(TGA)、接触角测试仪、扫描电子显微镜(SEM)对三嵌段聚合物的结构及聚合反应进行了表征与测试。结果表明三嵌段聚合物具有较好的热稳定性、疏水性和微相分离。
基金the Basic Frontier Science Research Program of Chinese Academy of Sciences(No.ZDBS-LY-DQC025)the National Natural Science Foundation of China(No.41706080)Shandong Key Laboratory of Corrosion Science。
文摘A novel silicone-based poly(urea-thiourea)/tannic acid composite(PDMS-P(Ua-TUa)-TA)with excellent mechanical,self-healing and antifouling properties is developed.The multiple dynamic hydrogen bonds formed by thiourea groups,urea groups,and tannic acid(TA)molecules ensured a tough elastomer(ultimate strength:2.47 MPa)with high stretchability(~1000%).TA molecules as partial hydrogen bonding cross-linking sites interacted rapidly with urea and thiourea groups before the migration of polymer chains,resulting in fast and efficient self-healing.Scratches on the film completely disappeared within12 min,and the repair efficiency of strength was up to 98.4%within 3 h under ambient condition.Selfhealing behavior was also evaluated in artificial seawater and the healing efficiency(HE)was 95.1%.Furthermore,TA uniformly dispersed in the polymer matrix provides good antibacterial and anti-diatom properties,as well as strong adhesion to the substrate(~2.2 MPa).Laboratory bioassays against marine bacteria adhesion(~96%,~95%and~93%reduction for P.sp.,E.coli,and S.aureus,respectively)and diatom attachment(~84%reduction)demonstrated an outstanding antifouling property of the PDMSP(Ua-TUa)-TA.This work provides a promising pathway towards the development of high-performance silicone-based coatings for marine anti-biofouling.
基金Supported by the National Natural Science Foundation of China(No.20474040).
文摘A new chromatographic method is described for the determination of specific refractive index increment（dn/dc）μ at a constant chemical potential,for polymer/mixed solvent systems.In this method the（dn/dc）is obtained by measuring the areas of solvated-polymer peaks when the mixed solvent is used as an eluent.Values of（dn/dc）μ for the poly（dimethylsiloxane）（PDMS）-benzene-methanol system,determined by the proposed method are in good agreement with those determined by the conventional dialysis method.The new approach has the advantages of simplicity,fast speed,and high reproducibility.The experimental results for stearic acid-chloroform-methanol system show that this method can also be applied to nonpolymer/mixed solvent systems for the determination of（dn/dc）μ.
