The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetam...The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetamide (DMAc). The poly (amic acid) films were obtained by solution-cast method from DMAc solutions and thermally converted into transparent, flexible and tough polyimide films. The wide-angle X-ray diffraction diagrams revealed that all the polyimides possessed amorphous character, and the regulation of those polyimides were decreased with the increase of the molar ratio of SIDA to PMDA. Differential scanning calorimeter measurements showed that the introduction of SIDA to polyimide backbone would make glass transition temperature shift to lower temperature. Thermogravimetric analyses indicated that the silicon-containing polyimides lowered decomposition temperature as compared with PMDA/4, 4′-ODA polyimides. However, UV-visible transmission and reflection spectra showed that the optical transparency of silicon-containing polyimide thin films was superior to that of PMDA/4, 4'-ODA polyimide thin films.展开更多
Vapor-liquid equilibrium (VLE) for a ternary system of methyldichlorosilane + methylvinyldichlorosi-lane + toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliome...Vapor-liquid equilibrium (VLE) for a ternary system of methyldichlorosilane + methylvinyldichlorosi-lane + toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer. The equilibrium compositions of the vapor phase of binary systems were calculated indirectly from the total pressure-temperature-liquid composition (pTx). The experimental data were correlated with the Wilson and NRTL(non-random two liquid) equations. The parameters of the Wilson model were employed to predict the ternary VLE data. The calculated boiling points were in good agreement with the experimental ones.展开更多
A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac-...A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.展开更多
A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative ...A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.展开更多
The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. I...The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. Isobaric VLE for the system methyldichlorosilane-dimethyldichlorosilane-benzene and isobaric VLE of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermo-dynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system was in a good agreement with the experimental results. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane.展开更多
Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor(TPPB).The liquid phase consisted of a mixture of water and PDMS 50(Poly Di Methyl Siloxane,i.e.silicone oil,viscosity of 46 m P...Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor(TPPB).The liquid phase consisted of a mixture of water and PDMS 50(Poly Di Methyl Siloxane,i.e.silicone oil,viscosity of 46 m Pa·s) in the volume ratio of 75%/25%.Two series of experiments were carried out:in the first,the reactor was sequentially supplied with toluene whereas in the second,toluene was continuously supplied.Activated sludge from the wastewater treatment plant of Beaurade(Rennes,France) was used at an initial concentration of 0.5 dry mass g·(mixture L)^(-1).The elimination capacity(EC) was investigated as well as the change in biomass concentration over time.Toluene biodegradation was very ef ficient(removal ef ficiency,RE=100%) for toluene flows ranging from 0.2 to 1.2 ml·h^(-1),corresponding to elimination capacities of up to 104 g·m^(-3)·h^(-1).For a toluene flow of 1.2 ml·h^(-1),the biomass concentration measured at the end of the experiment was 4.7 dry mass g·(mixture L)^(-1).The oxygen concentration in the liquid phase was clearly not a limiting factor in these operating conditions.Based on these results,an extrapolation leading to the design of a large-scale pilot TPPB can now be considered to study toluene degradation performances in industrial conditions.展开更多
We proposed a novel method of fabricating polydimethylsiloxane (PDMS) microfluidic chip polymer master molds in this paper. The method mainly includes two steps. First, a stainless steel slice was laser etched to form...We proposed a novel method of fabricating polydimethylsiloxane (PDMS) microfluidic chip polymer master molds in this paper. The method mainly includes two steps. First, a stainless steel slice was laser etched to form a metal model. Then, the organic solution of poly(methyl methacrylate) (PMMA) was casted onto the metal model to fabricate the PMMA master which subsequently would be used to fabricate PDMS chips. We systematically researched different laser parameters influencing the surface status of microchannels and obtained optimized etching parameters. We investigated and optimized the organic solution composition of PMMA while casting chip masters, and developed a method to form fine polymer masters using two different viscosity solutions to cast the model in turn, and studied the repeatable replication. Then, we investigated physical performance of this chip and evaluated the practicability by analyzing Rhodamine B. Compared with present methods, the proposed method does not need photolithography on photoresistant and chemical etching. The entire fabricating progress is simple, fast, low-cost and can be controlled easily. Only several minutes are required to make a metal model, 3 hours for a PMMA master, and one day for PDMS chips.展开更多
This study is to analyze the influence of the modifier, 5～25 wt % titanium tetrabutoxide (TBO), on the hardness and elastic modulus of the films based on SSO deriving from hydrolytic condensation of (3-glycidoxypropy...This study is to analyze the influence of the modifier, 5～25 wt % titanium tetrabutoxide (TBO), on the hardness and elastic modulus of the films based on SSO deriving from hydrolytic condensation of (3-glycidoxypropyl)trimethoxysilane (GPMS) and vinyltrimethoxysilane (VMS), by the continuous stiffness measurement (CSM) technique of an instrumented-indentation testing (IIT) device. Films were synthesized by adding the stoichiometric amount of ethylenediamine (EDA) and benzoyl proxide (BPO) to SSO solutions in ethanol, dip-coating over glass substrates, and curing using an appropriate thermal cycle. Intrinsic values of hardness and elastic modulus were determined with the average values in “plateau region” from “four-layer” explanation. And the brittle index of the modified coating systems was analyzed.展开更多
We studied the dielectric properties of organosilicon-containing helical cyclopolymer PbMA which consists of PMMA main chains and tetramethyldisiloxane side rings. PbMA formed films with excellent uniformity through s...We studied the dielectric properties of organosilicon-containing helical cyclopolymer PbMA which consists of PMMA main chains and tetramethyldisiloxane side rings. PbMA formed films with excellent uniformity through spin-coating onto highly n-doped silicon （n-Si） wafers for constructing devices of dielectric measurements, on which the dielectric properties and I-V characteristics of PbMA were studied. PbMA has a much lower dielectric constant （lower than 2.6） in the frequency range of 10-105 Hz, and better thermal stability than PMMA does. I-V data showed that the metal/PbMA/n-Si devices have different conducting directions, depending on whether Au or Al deposited over PbMA layers.展开更多
文摘The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetamide (DMAc). The poly (amic acid) films were obtained by solution-cast method from DMAc solutions and thermally converted into transparent, flexible and tough polyimide films. The wide-angle X-ray diffraction diagrams revealed that all the polyimides possessed amorphous character, and the regulation of those polyimides were decreased with the increase of the molar ratio of SIDA to PMDA. Differential scanning calorimeter measurements showed that the introduction of SIDA to polyimide backbone would make glass transition temperature shift to lower temperature. Thermogravimetric analyses indicated that the silicon-containing polyimides lowered decomposition temperature as compared with PMDA/4, 4′-ODA polyimides. However, UV-visible transmission and reflection spectra showed that the optical transparency of silicon-containing polyimide thin films was superior to that of PMDA/4, 4'-ODA polyimide thin films.
基金Supported by the Natural Science Foundation of Jiangxi Province(No.0020019).
文摘Vapor-liquid equilibrium (VLE) for a ternary system of methyldichlorosilane + methylvinyldichlorosi-lane + toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer. The equilibrium compositions of the vapor phase of binary systems were calculated indirectly from the total pressure-temperature-liquid composition (pTx). The experimental data were correlated with the Wilson and NRTL(non-random two liquid) equations. The parameters of the Wilson model were employed to predict the ternary VLE data. The calculated boiling points were in good agreement with the experimental ones.
文摘A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.
基金Supported by the National Natural Science Foundation of China(21306088)National Key Technologies R&D Program of China(2015BAD15B07)+1 种基金State Key Laboratory of Chemical Engineering(SKL-Ch E-13A01,Tsinghua University,China)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,China)
文摘A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.
基金Project supported by the Foundation of Science and Technology, theMinistry of Education (No. 03071), and The Natural Science Foun-dation of Jiangxi Province (No. 0320013), China
文摘The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. Isobaric VLE for the system methyldichlorosilane-dimethyldichlorosilane-benzene and isobaric VLE of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermo-dynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system was in a good agreement with the experimental results. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane.
基金the French Environment and Energy Management Agency(ADEME) for their support through a PhD fellowship for M.Guillerm
文摘Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor(TPPB).The liquid phase consisted of a mixture of water and PDMS 50(Poly Di Methyl Siloxane,i.e.silicone oil,viscosity of 46 m Pa·s) in the volume ratio of 75%/25%.Two series of experiments were carried out:in the first,the reactor was sequentially supplied with toluene whereas in the second,toluene was continuously supplied.Activated sludge from the wastewater treatment plant of Beaurade(Rennes,France) was used at an initial concentration of 0.5 dry mass g·(mixture L)^(-1).The elimination capacity(EC) was investigated as well as the change in biomass concentration over time.Toluene biodegradation was very ef ficient(removal ef ficiency,RE=100%) for toluene flows ranging from 0.2 to 1.2 ml·h^(-1),corresponding to elimination capacities of up to 104 g·m^(-3)·h^(-1).For a toluene flow of 1.2 ml·h^(-1),the biomass concentration measured at the end of the experiment was 4.7 dry mass g·(mixture L)^(-1).The oxygen concentration in the liquid phase was clearly not a limiting factor in these operating conditions.Based on these results,an extrapolation leading to the design of a large-scale pilot TPPB can now be considered to study toluene degradation performances in industrial conditions.
基金Funded by the Natural Science Foundation of China (No. 20775096)
文摘We proposed a novel method of fabricating polydimethylsiloxane (PDMS) microfluidic chip polymer master molds in this paper. The method mainly includes two steps. First, a stainless steel slice was laser etched to form a metal model. Then, the organic solution of poly(methyl methacrylate) (PMMA) was casted onto the metal model to fabricate the PMMA master which subsequently would be used to fabricate PDMS chips. We systematically researched different laser parameters influencing the surface status of microchannels and obtained optimized etching parameters. We investigated and optimized the organic solution composition of PMMA while casting chip masters, and developed a method to form fine polymer masters using two different viscosity solutions to cast the model in turn, and studied the repeatable replication. Then, we investigated physical performance of this chip and evaluated the practicability by analyzing Rhodamine B. Compared with present methods, the proposed method does not need photolithography on photoresistant and chemical etching. The entire fabricating progress is simple, fast, low-cost and can be controlled easily. Only several minutes are required to make a metal model, 3 hours for a PMMA master, and one day for PDMS chips.
文摘This study is to analyze the influence of the modifier, 5～25 wt % titanium tetrabutoxide (TBO), on the hardness and elastic modulus of the films based on SSO deriving from hydrolytic condensation of (3-glycidoxypropyl)trimethoxysilane (GPMS) and vinyltrimethoxysilane (VMS), by the continuous stiffness measurement (CSM) technique of an instrumented-indentation testing (IIT) device. Films were synthesized by adding the stoichiometric amount of ethylenediamine (EDA) and benzoyl proxide (BPO) to SSO solutions in ethanol, dip-coating over glass substrates, and curing using an appropriate thermal cycle. Intrinsic values of hardness and elastic modulus were determined with the average values in “plateau region” from “four-layer” explanation. And the brittle index of the modified coating systems was analyzed.
基金This work was supported by the National Natural Science Foundation of China （No.51673181）.
文摘We studied the dielectric properties of organosilicon-containing helical cyclopolymer PbMA which consists of PMMA main chains and tetramethyldisiloxane side rings. PbMA formed films with excellent uniformity through spin-coating onto highly n-doped silicon （n-Si） wafers for constructing devices of dielectric measurements, on which the dielectric properties and I-V characteristics of PbMA were studied. PbMA has a much lower dielectric constant （lower than 2.6） in the frequency range of 10-105 Hz, and better thermal stability than PMMA does. I-V data showed that the metal/PbMA/n-Si devices have different conducting directions, depending on whether Au or Al deposited over PbMA layers.
