The synthesis and surfactant activities of two new cationic gemini surfactants containing triazole compound as spacer were described. Their critical micelle concentrations (CMC), which are 1.8×10-4 mol/L and 3.9...The synthesis and surfactant activities of two new cationic gemini surfactants containing triazole compound as spacer were described. Their critical micelle concentrations (CMC), which are 1.8×10-4 mol/L and 3.9×10-4 mol/L respectively, are much lower than that of conventional surfactant cetyltrimethyl ammonium chloride (CTAC). In addition, compared with some gemini surfactants containing phenylene, xylylene and stilbenyl as spacer, this new kind of surfactants has good solubility in water at room temperature because of containing more hydrophilic groups or atoms in molecules.展开更多
The synthesis and surface activity of gemini surfactants with ester bond as spacer are described. Their critical micelle concentrations (CMC) are much lower than that of conventional surfactants, i.e., 1.62×10^...The synthesis and surface activity of gemini surfactants with ester bond as spacer are described. Their critical micelle concentrations (CMC) are much lower than that of conventional surfactants, i.e., 1.62×10^-5, 1.38×10^-5, 1.28×10^-5 mol·L^-1 for gemini Ⅰ, Ⅱ and Ⅲ respectively. Surface tension at the CMC of gemini Ⅰ, Ⅱ and Ⅲ were 36.4, 38.5, 41.2 mN · m^-1. The physico-chemical properties such as Krafft points, foaming abilities and emulsifying power were also investigated. It is found that the title compounds have low Krafft points and show good solubility in water. The gemini surfactants synthesized also exhibit good foaming properties and excellent emulsifying power toward toluene. The foaming abilities and emulsifying power increase with the increase in carbon number of hydrophobic chain, and this might be caused by the sheer viscosity of different gemini surfactant solution.展开更多
Novel quaternary ammonium cationic gemini surfactants, with two hydrocarbon chains and an adamantane core, were designed and synthesized by three-step reactions from adamantane. The structure of obtained surfactants w...Novel quaternary ammonium cationic gemini surfactants, with two hydrocarbon chains and an adamantane core, were designed and synthesized by three-step reactions from adamantane. The structure of obtained surfactants were confirmed by 1H NMR, FTIR and elements analysis and the surface properties of these surfactants were also studied by surface tension measurements. These target surfactants exhibit much lower critical micelle concentrations (CMC) and higher efficiency in lowering the surface tension of water than typical surfactants.展开更多
The synthesis of a new series of asymmetric cationic gemini surfactant and the investigation of their micellization behaviors by electronic spin resonance (ESR) as well as the surface tension measurements were reporte...The synthesis of a new series of asymmetric cationic gemini surfactant and the investigation of their micellization behaviors by electronic spin resonance (ESR) as well as the surface tension measurements were reported. 4 Oxo 2,2,6,6 te^tra^me^thyl^pi^pe^ri^dine N oxyl (4 oxo TEMPO) is used as the spin probe. The surfactants studied have the general formula [C n H 2 n +1 N +(CH 3) 2C 6H 12 N +(CH 3) 2C m H 2 m +1 ]Br 2 -, referred to as dimeric n 6 m surfactants, in which n and m are the numbers of carbon atoms in the asymmetric side alkyl chains. From the experimental data, rotational correlation time τ c, surface tension and critical micelle concentration (cmc) values, the physical properties of these new surfactants have preliminarily been evaluated. It is shown that this new series of asymmetric gemini surfactants has interesting micellization behaviors, and they are very different in aggregating tendency from their asymmetric analogues.展开更多
A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations (cmc) is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, ...A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations (cmc) is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.展开更多
Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, resp...Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.展开更多
We synthesized a series of mesoporous silica microparticles (MSs) using cationic gemini surfactants C14.2-n (n=2, 6, 10, 14) as templates. The porous structures and pore size of these MSs can be tuned by varying t...We synthesized a series of mesoporous silica microparticles (MSs) using cationic gemini surfactants C14.2-n (n=2, 6, 10, 14) as templates. The porous structures and pore size of these MSs can be tuned by varying the length of alkyl chain in gemini surfaetant templates. These MSs showed effective doxorubicin (DOX) loading and a pH-responsive drug release characteristics. These results indicate that the MSs, especially the hollow mesoporous silica nanoparticles, have great potential for biomedical applications.展开更多
Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable dep...Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.展开更多
How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing.In this work,a novel amino-based Gemini surf...How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing.In this work,a novel amino-based Gemini surfactant butadiyl-1,4-bis(dimethyl dodecylammonium bromide)(BBDB) was prepared and first utilized as a novel collector for kaolinite flotation.Its flotation performance for kaolinite was compared with that of the common monomolecular surfactant 1-dodecylamine(DDA) by micro-flotation tests.The tests results indicated that 95% kaolinite recovery was obtained using 2.0×10^(-4) mol/L BBDB at 25℃ which was half of the dosage when DDA obtained the maximum kaolinite recovery of81%.At extremely low temperature(0℃),3.0×10^(-4) mol/L BBDB could still collect 91% kaolinite,while DDA showed a frustrating ability.The contact angle tests indicated that BBDB could still significantly improve the hydrophobicity of the kaolinite surface(contact angle 71.7°) than DDA(contact angle only25.8°) at 0℃.The Krafft point comparison tests indicated that BBDB had a much lower Krafft point(below0℃) than DDA.Fourier transform infrared spectroscopy(FTIR)-spectrum analysis and zeta potential measurements showed that BBDB was physically adsorbed on the surface of kaolinite through electrostatic interaction.展开更多
A new surfactant of Gemini-type,N,N'-((phthylbis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethyldodecan-1-aminium bromide)is prepped&confirmed.The dissolution suppression impact of the new compound on steel is perf...A new surfactant of Gemini-type,N,N'-((phthylbis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethyldodecan-1-aminium bromide)is prepped&confirmed.The dissolution suppression impact of the new compound on steel is performed in 1 mol·L^(-1)HCl environment by means of chemical and electrochemical methods.The prepared surfactant is an agreeable dissolution inhibitor for steel.The mitigation efficacy rises with the quantity of the compound.The surfactant belongs to inhibitors of mixed-type.The adsorption of the synthesized compound followed the Langmuir's model.The negative magnitudes of bothΔG_(ads)^(θ) andΔH^(adsθ)indicate that the adsorption process proceeds from its own accord and exothermic.The mechanism of adsorption is elucidated by scanning microscopy.It is established that the transfer resistance(R_(ct))value rose,where the value of the phase element(CPE)reduced with the amount of synthesized inhibitor.According to the experimental data arrived by surface tension measurements,the prepared compound is a powerful active agent at the air/water boundary.展开更多
Flexible p–n thermoelectric generator(TEG)technology has rapidly advanced with power enhancement and size reduction.To achieve a stable power supply and highly efficient energy conversion,absolute chemical stability ...Flexible p–n thermoelectric generator(TEG)technology has rapidly advanced with power enhancement and size reduction.To achieve a stable power supply and highly efficient energy conversion,absolute chemical stability of n-type materials is essential to ensuring large temperature differences between device terminals and ambient stability.With the aim of improving the long-term stability of the n-type operation of carbon nanotubes(CNTs)in air and water,this study uses cationic surfactants,such as octylene-1,8-bis(dimethyldodecylammonium bromide)(12-8-12),a gemini surfactant,to stabilize the nanotubes in a coating,which retains the n-doped state for more than 28 days after exposure to air and water in experiments.TEGs with 10 p-n units of 12-8-12/CNT(n-type)and sodium dodecylbenzene sulfonate/CNT(p-type)layers are manufactured,and their water stability is evaluated.The initial maximum output of 16.1μW(75 K temperature difference)is retained after water immersion for 40 days without using a sealant to prevent TEG module degradation.The excellent stability of these CNT-based TEGs makes them suitable for underwater applications,such as battery-free health monitoring and information gathering systems,and facilitates the development of soft electronics.展开更多
A smart response fluid was designed and developed to overcome the challenges of gas channeling during CO_(2)flooding in low-permeability,tight oil reservoirs.The fluid is based on Gemini surfactant with self-assembly ...A smart response fluid was designed and developed to overcome the challenges of gas channeling during CO_(2)flooding in low-permeability,tight oil reservoirs.The fluid is based on Gemini surfactant with self-assembly capabilities,and the tertiary amine group serves as the response component.The responsive characteristics and corresponding mechanism of the smart fluid during the interaction with CO_(2)/oil were studied,followed by the shear characteristics of the thickened aggregates obtained by the smart fluid responding to CO_(2).The temperature and salt resistance of the smart fluid and the aggregates were evaluated,and their feasibility and effectiveness in sweep-controlling during the CO_(2)flooding were confirmed.This research reveals:(1)Thickened aggregates could be assembled since the smart fluid interacted with CO_(2).When the mass fraction of the smart fluid ranged from 0.05%to 2.50%,the thickening ratio changed from 9 to 246,with viscosity reaching 13 to 3100 mPas.As a result,the sweep efficiency in low-permeability core models could be increased in our experiments.(2)When the smart fluid(0.5%to 1.0%)was exposed to simulated oil,the oil/fluid interfacial tension decreased to the level of 1×10^(-2)mN/m.Furthermore,the vesicle-like micelles in the smart fluid completely transformed into spherical micelles when the fluid was exposed to simulated oil with the saturation greater than 10%.As a result,the smart fluid could maintain low oil/fluid interfacial tension,and would not be thickened after oil exposure.(3)When the smart fluid interacted with CO_(2),the aggregates showed self-healing properties in terms of shear-thinning,static-thickening,and structural integrity after several shear-static cycles.Therefore,this fluid is safe to be placed in deep reservoirs.(4)The long-term temperature and salt resistance of the smart fluid and thickened aggregates have been confirmed.展开更多
We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measuremen...We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measurement (STm) and Brewster Angle Microscopy (BAM). Surfactant of 3, 4-bis-alkyloxycarbonyl-hexanedioic acid has a gemini type structure. π-A isotherm curves (STm) of two gemini surfactants of n = 12 and 14 showed gradual increase in surface pressure, while that of n = 16 showed gradual increase, a stagnant range and finally steep increase. BAM observation showed each image corresponding to the result of STm measurement. From STm and BAM results of surfactants, it is found that surfactant of n = 12 and 14 form Liquid-Expand (LE) type monolayer, while that of n = 16 formed Liquid-Condensed (LC) type monolayer including LE-LC phase transition.展开更多
A novel two-dimensional nanopattemed TiO2 thin film has been synthesized through the interaction between cationic Gemini surfactant molecules and the prepared TiO2 colloid nanoparticles with average diameters of 8 nm ...A novel two-dimensional nanopattemed TiO2 thin film has been synthesized through the interaction between cationic Gemini surfactant molecules and the prepared TiO2 colloid nanoparticles with average diameters of 8 nm by controlling the surface pressure of the monolayer. TEM photographs from the formed Gemini-TiO2 composite monolayer confirm that the prepared TiO2 film is of a branch nanopattern.展开更多
Different routes,including the replacements of the template,addition of pore expander and hydrothermal post-synthesis treatment have been used for the pore engineering of spherical MCM-41.A comparison among the pore e...Different routes,including the replacements of the template,addition of pore expander and hydrothermal post-synthesis treatment have been used for the pore engineering of spherical MCM-41.A comparison among the pore engineering effects of these methods has been made.The results show that the hydrothermal post-synthesis treatment affords the synthesized material with a larger pore size and narrow pore size distribution without changing the spherical morphology.As far as the pore-size expansion is concerned,the addition of DMTA is the most effective one,but this might be limited by the spherical morphology.Combining the replacement of C 16TMABr with the Gemini surfactant GEM 16-8-16 with an addition of DMTA gives rise to the largest pore volume and surface area.展开更多
A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups((diethylhexanedioate) diyl-a,v-bis(dimethyl dodecyl ammonium bromide) referred to as 12-10-12)was synthesized with h...A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups((diethylhexanedioate) diyl-a,v-bis(dimethyl dodecyl ammonium bromide) referred to as 12-10-12)was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.展开更多
The rheological behavior of the aqueous solutions of mixed sulfate gemini surfactant with no spacer group, referred to as d-C12S, and dodecyltrimethylammonium bromide (C12TABr) at a total concentration of 100 mmol,L...The rheological behavior of the aqueous solutions of mixed sulfate gemini surfactant with no spacer group, referred to as d-C12S, and dodecyltrimethylammonium bromide (C12TABr) at a total concentration of 100 mmol,L-1 but different molar ratios of ClzTABr to d-C12S (a1) was investigated using steady rate and frequency sweep measurements. The wormlike micelles were formed over a narrow a1 range of 0.20-0.27. The viscoelastic solutions exhibited Maxwell fluid behavior. At the optimum molar ratio of 0.25, the zero-shear viscosity was as high as 600 paos and the length of the mixed wormlike micelle was about 0.45-0.85 pm. The present result provides an exam- ple to construct long wormlike micelles by anionic gemini surfactant.展开更多
A simple solution-phase approach has been demonstrated for the large-scale synthesis of silver nanowires with diameters in the range of 15–25 nm,and lengths usually in the range of tens of micrometers.In the presence...A simple solution-phase approach has been demonstrated for the large-scale synthesis of silver nanowires with diameters in the range of 15–25 nm,and lengths usually in the range of tens of micrometers.In the presence of gemini surfactant 1,3-bis(cetyldimethylammonium)propane dibro-mide(16-3-16),the growth of silver could be directed into a highly anisotropic mode to form uniform nanowires with aspect ratios up to about 2,000.X-ray photoelectron spec-troscopy(XPS),transmission electron microscopy(TEM),energy-dispersive X-ray(EDX),X-ray powder diffraction(XRD),electron diffraction(ED),and UV-vis absorption spectroscopy,were used to characterize the as-prepared silver nanowires,indicating the formation of a highly pure phase,good crystallinity,as well as a uniform diameter.展开更多
Wax molecules tend to aggregate,and form wax solid at low temperature and result in a wax deposition.Chemical wax inhibitors are introduced to prevent wax deposition.However,the performance of chemical wax inhibitors ...Wax molecules tend to aggregate,and form wax solid at low temperature and result in a wax deposition.Chemical wax inhibitors are introduced to prevent wax deposition.However,the performance of chemical wax inhibitors is temperature dependent.Computational method using Molecular Dynamics(MD)simulation is used in this research to investigate how temperature affects wax inhibition using 2,5,8,11 Tetramethyl 6 dodecyn-5,8 Diol Ethoxylate Gemini surfactant(GS)and nanoparticles silicon dioxide(NP1),tin oxide(NP2),and nickel oxide(NP3).Wax-wax interaction of H58⋯H61of n-icosane and wax-solute interaction of hydrogen atom from n-icosane wax and carbonyl oxygen atoms from GS and NPs was investigated via radial distribution function analysis(rdf).The findings revealed that GS/NPs blends have a better chance of wax inhibition than corresponding individuals.Besides that,wax-wax interaction was strongest at 288K,indicating the higher chances of wax formation at low temperature.MD simulation is a promising tool for identifying atoms responsible for the wax formation and inhibition and can be used for chemical wax inhibitor screening for different temperature.展开更多
基金We are grateful for the financial support from the National Natural Science Foundation of China(29971001,20031010)the Naturai Science Foundation of Anhui Province(0045115)the Science Foundation for Excellent Young Teachers of Universities of Anhui Province(01080309).
文摘The synthesis and surfactant activities of two new cationic gemini surfactants containing triazole compound as spacer were described. Their critical micelle concentrations (CMC), which are 1.8×10-4 mol/L and 3.9×10-4 mol/L respectively, are much lower than that of conventional surfactant cetyltrimethyl ammonium chloride (CTAC). In addition, compared with some gemini surfactants containing phenylene, xylylene and stilbenyl as spacer, this new kind of surfactants has good solubility in water at room temperature because of containing more hydrophilic groups or atoms in molecules.
基金the Natural Science Foundation of Hubei Province, China (2000J023)
文摘The synthesis and surface activity of gemini surfactants with ester bond as spacer are described. Their critical micelle concentrations (CMC) are much lower than that of conventional surfactants, i.e., 1.62×10^-5, 1.38×10^-5, 1.28×10^-5 mol·L^-1 for gemini Ⅰ, Ⅱ and Ⅲ respectively. Surface tension at the CMC of gemini Ⅰ, Ⅱ and Ⅲ were 36.4, 38.5, 41.2 mN · m^-1. The physico-chemical properties such as Krafft points, foaming abilities and emulsifying power were also investigated. It is found that the title compounds have low Krafft points and show good solubility in water. The gemini surfactants synthesized also exhibit good foaming properties and excellent emulsifying power toward toluene. The foaming abilities and emulsifying power increase with the increase in carbon number of hydrophobic chain, and this might be caused by the sheer viscosity of different gemini surfactant solution.
基金financial support by the Key Program for Scientific and Technological Innovations of Higher Education Institutes in Guangdong Province(No.CXZD1022)
文摘Novel quaternary ammonium cationic gemini surfactants, with two hydrocarbon chains and an adamantane core, were designed and synthesized by three-step reactions from adamantane. The structure of obtained surfactants were confirmed by 1H NMR, FTIR and elements analysis and the surface properties of these surfactants were also studied by surface tension measurements. These target surfactants exhibit much lower critical micelle concentrations (CMC) and higher efficiency in lowering the surface tension of water than typical surfactants.
文摘The synthesis of a new series of asymmetric cationic gemini surfactant and the investigation of their micellization behaviors by electronic spin resonance (ESR) as well as the surface tension measurements were reported. 4 Oxo 2,2,6,6 te^tra^me^thyl^pi^pe^ri^dine N oxyl (4 oxo TEMPO) is used as the spin probe. The surfactants studied have the general formula [C n H 2 n +1 N +(CH 3) 2C 6H 12 N +(CH 3) 2C m H 2 m +1 ]Br 2 -, referred to as dimeric n 6 m surfactants, in which n and m are the numbers of carbon atoms in the asymmetric side alkyl chains. From the experimental data, rotational correlation time τ c, surface tension and critical micelle concentration (cmc) values, the physical properties of these new surfactants have preliminarily been evaluated. It is shown that this new series of asymmetric gemini surfactants has interesting micellization behaviors, and they are very different in aggregating tendency from their asymmetric analogues.
文摘A series of piperazine-based Gemini and Bola surfactants were synthesized. Gemini 1 and 5 have well surface activities. Their critical micelle concentrations (cmc) is 6.47×10^-4 mol/L and 1.17×10^-3mol/L, respectively. Bola surfactants 2 and compound 3, possessing better water solubility, have lower surface activities. Calculation, carried out by MM2 energy minimization, showed that compound with more hydrophobic chains in a spacer of limited length is difficult to be synthesized.
文摘Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.
文摘We synthesized a series of mesoporous silica microparticles (MSs) using cationic gemini surfactants C14.2-n (n=2, 6, 10, 14) as templates. The porous structures and pore size of these MSs can be tuned by varying the length of alkyl chain in gemini surfaetant templates. These MSs showed effective doxorubicin (DOX) loading and a pH-responsive drug release characteristics. These results indicate that the MSs, especially the hollow mesoporous silica nanoparticles, have great potential for biomedical applications.
基金supported by the National Natural Science Foundation of China(U2001217,22261160370 and 21972006)Guangdong-Hong Kong-Macao Joint Innovation Foundation(2021A0505110003)+1 种基金Shenzhen Basic Research(JCYJ20220818101018038 and JCYJ20200109110628172)Guangdong Province Regional Joint Innovation Foundation(2020B1515120039)。
文摘Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules.
基金the support of the National Natural Science Foundation of China (No. U1607108)Natural Science Foundation of Jiangxi, China (No. 20202ACBL213008)。
文摘How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing.In this work,a novel amino-based Gemini surfactant butadiyl-1,4-bis(dimethyl dodecylammonium bromide)(BBDB) was prepared and first utilized as a novel collector for kaolinite flotation.Its flotation performance for kaolinite was compared with that of the common monomolecular surfactant 1-dodecylamine(DDA) by micro-flotation tests.The tests results indicated that 95% kaolinite recovery was obtained using 2.0×10^(-4) mol/L BBDB at 25℃ which was half of the dosage when DDA obtained the maximum kaolinite recovery of81%.At extremely low temperature(0℃),3.0×10^(-4) mol/L BBDB could still collect 91% kaolinite,while DDA showed a frustrating ability.The contact angle tests indicated that BBDB could still significantly improve the hydrophobicity of the kaolinite surface(contact angle 71.7°) than DDA(contact angle only25.8°) at 0℃.The Krafft point comparison tests indicated that BBDB had a much lower Krafft point(below0℃) than DDA.Fourier transform infrared spectroscopy(FTIR)-spectrum analysis and zeta potential measurements showed that BBDB was physically adsorbed on the surface of kaolinite through electrostatic interaction.
文摘A new surfactant of Gemini-type,N,N'-((phthylbis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethyldodecan-1-aminium bromide)is prepped&confirmed.The dissolution suppression impact of the new compound on steel is performed in 1 mol·L^(-1)HCl environment by means of chemical and electrochemical methods.The prepared surfactant is an agreeable dissolution inhibitor for steel.The mitigation efficacy rises with the quantity of the compound.The surfactant belongs to inhibitors of mixed-type.The adsorption of the synthesized compound followed the Langmuir's model.The negative magnitudes of bothΔG_(ads)^(θ) andΔH^(adsθ)indicate that the adsorption process proceeds from its own accord and exothermic.The mechanism of adsorption is elucidated by scanning microscopy.It is established that the transfer resistance(R_(ct))value rose,where the value of the phase element(CPE)reduced with the amount of synthesized inhibitor.According to the experimental data arrived by surface tension measurements,the prepared compound is a powerful active agent at the air/water boundary.
基金The authors gratefully acknowledge financial support from Key Technologies R&D Program Foundation of China(02BA312B07)the National Natural Science Foundation of China(No.20303011)Natural Science Foundation of Shandong Province(Y 2001 B08).
基金Mazda FoundationTEPCO Memorial FoundationJapan Society for the Promotion of Science,Grant/Award Numbers:19K05633,21K14428。
文摘Flexible p–n thermoelectric generator(TEG)technology has rapidly advanced with power enhancement and size reduction.To achieve a stable power supply and highly efficient energy conversion,absolute chemical stability of n-type materials is essential to ensuring large temperature differences between device terminals and ambient stability.With the aim of improving the long-term stability of the n-type operation of carbon nanotubes(CNTs)in air and water,this study uses cationic surfactants,such as octylene-1,8-bis(dimethyldodecylammonium bromide)(12-8-12),a gemini surfactant,to stabilize the nanotubes in a coating,which retains the n-doped state for more than 28 days after exposure to air and water in experiments.TEGs with 10 p-n units of 12-8-12/CNT(n-type)and sodium dodecylbenzene sulfonate/CNT(p-type)layers are manufactured,and their water stability is evaluated.The initial maximum output of 16.1μW(75 K temperature difference)is retained after water immersion for 40 days without using a sealant to prevent TEG module degradation.The excellent stability of these CNT-based TEGs makes them suitable for underwater applications,such as battery-free health monitoring and information gathering systems,and facilitates the development of soft electronics.
基金Supported by the PetroChina Science and Technology Major Project(2019-E2607)PetroChina Exploration and Production Company Science and Technology Project(KS2020-01-09).
文摘A smart response fluid was designed and developed to overcome the challenges of gas channeling during CO_(2)flooding in low-permeability,tight oil reservoirs.The fluid is based on Gemini surfactant with self-assembly capabilities,and the tertiary amine group serves as the response component.The responsive characteristics and corresponding mechanism of the smart fluid during the interaction with CO_(2)/oil were studied,followed by the shear characteristics of the thickened aggregates obtained by the smart fluid responding to CO_(2).The temperature and salt resistance of the smart fluid and the aggregates were evaluated,and their feasibility and effectiveness in sweep-controlling during the CO_(2)flooding were confirmed.This research reveals:(1)Thickened aggregates could be assembled since the smart fluid interacted with CO_(2).When the mass fraction of the smart fluid ranged from 0.05%to 2.50%,the thickening ratio changed from 9 to 246,with viscosity reaching 13 to 3100 mPas.As a result,the sweep efficiency in low-permeability core models could be increased in our experiments.(2)When the smart fluid(0.5%to 1.0%)was exposed to simulated oil,the oil/fluid interfacial tension decreased to the level of 1×10^(-2)mN/m.Furthermore,the vesicle-like micelles in the smart fluid completely transformed into spherical micelles when the fluid was exposed to simulated oil with the saturation greater than 10%.As a result,the smart fluid could maintain low oil/fluid interfacial tension,and would not be thickened after oil exposure.(3)When the smart fluid interacted with CO_(2),the aggregates showed self-healing properties in terms of shear-thinning,static-thickening,and structural integrity after several shear-static cycles.Therefore,this fluid is safe to be placed in deep reservoirs.(4)The long-term temperature and salt resistance of the smart fluid and thickened aggregates have been confirmed.
文摘We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measurement (STm) and Brewster Angle Microscopy (BAM). Surfactant of 3, 4-bis-alkyloxycarbonyl-hexanedioic acid has a gemini type structure. π-A isotherm curves (STm) of two gemini surfactants of n = 12 and 14 showed gradual increase in surface pressure, while that of n = 16 showed gradual increase, a stagnant range and finally steep increase. BAM observation showed each image corresponding to the result of STm measurement. From STm and BAM results of surfactants, it is found that surfactant of n = 12 and 14 form Liquid-Expand (LE) type monolayer, while that of n = 16 formed Liquid-Condensed (LC) type monolayer including LE-LC phase transition.
基金supported by the National Natural Science Foundation of China(No.20473057)Shanghai Nanotechnology Promotion Center(No.0352nm094,No.0452nm088).
文摘A novel two-dimensional nanopattemed TiO2 thin film has been synthesized through the interaction between cationic Gemini surfactant molecules and the prepared TiO2 colloid nanoparticles with average diameters of 8 nm by controlling the surface pressure of the monolayer. TEM photographs from the formed Gemini-TiO2 composite monolayer confirm that the prepared TiO2 film is of a branch nanopattern.
文摘Different routes,including the replacements of the template,addition of pore expander and hydrothermal post-synthesis treatment have been used for the pore engineering of spherical MCM-41.A comparison among the pore engineering effects of these methods has been made.The results show that the hydrothermal post-synthesis treatment affords the synthesized material with a larger pore size and narrow pore size distribution without changing the spherical morphology.As far as the pore-size expansion is concerned,the addition of DMTA is the most effective one,but this might be limited by the spherical morphology.Combining the replacement of C 16TMABr with the Gemini surfactant GEM 16-8-16 with an addition of DMTA gives rise to the largest pore volume and surface area.
基金supported by the Talent Foundation of Anhui Science and Technology University (No. ZRC2014401)
文摘A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups((diethylhexanedioate) diyl-a,v-bis(dimethyl dodecyl ammonium bromide) referred to as 12-10-12)was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.
基金Project supported by the Fundamental Research Funds for the Central Universities (No. JUSRP111A06), the National Natural Science Foundation of China (Nos. 20673021, 20873024 and 21073081), the Professional Foundation of Fuzhou University (No. XRC-0639), and the Fujian Provincial Natural Science Foundation of China (No. 2010J01038).
文摘The rheological behavior of the aqueous solutions of mixed sulfate gemini surfactant with no spacer group, referred to as d-C12S, and dodecyltrimethylammonium bromide (C12TABr) at a total concentration of 100 mmol,L-1 but different molar ratios of ClzTABr to d-C12S (a1) was investigated using steady rate and frequency sweep measurements. The wormlike micelles were formed over a narrow a1 range of 0.20-0.27. The viscoelastic solutions exhibited Maxwell fluid behavior. At the optimum molar ratio of 0.25, the zero-shear viscosity was as high as 600 paos and the length of the mixed wormlike micelle was about 0.45-0.85 pm. The present result provides an exam- ple to construct long wormlike micelles by anionic gemini surfactant.
基金supported by the National Natural Science Foundation of China(Grant No.20490200)the Doctoral Research Foundation Sponsored by the Ministry of Education of China(Granct No.20050251004)Shanghai Municipal Commission of Education in China。
文摘A simple solution-phase approach has been demonstrated for the large-scale synthesis of silver nanowires with diameters in the range of 15–25 nm,and lengths usually in the range of tens of micrometers.In the presence of gemini surfactant 1,3-bis(cetyldimethylammonium)propane dibro-mide(16-3-16),the growth of silver could be directed into a highly anisotropic mode to form uniform nanowires with aspect ratios up to about 2,000.X-ray photoelectron spec-troscopy(XPS),transmission electron microscopy(TEM),energy-dispersive X-ray(EDX),X-ray powder diffraction(XRD),electron diffraction(ED),and UV-vis absorption spectroscopy,were used to characterize the as-prepared silver nanowires,indicating the formation of a highly pure phase,good crystallinity,as well as a uniform diameter.
基金The authors gratefully acknowledge the financial support provided by Universiti Malaysia Pahang under Internal Research grant RDU200302.
文摘Wax molecules tend to aggregate,and form wax solid at low temperature and result in a wax deposition.Chemical wax inhibitors are introduced to prevent wax deposition.However,the performance of chemical wax inhibitors is temperature dependent.Computational method using Molecular Dynamics(MD)simulation is used in this research to investigate how temperature affects wax inhibition using 2,5,8,11 Tetramethyl 6 dodecyn-5,8 Diol Ethoxylate Gemini surfactant(GS)and nanoparticles silicon dioxide(NP1),tin oxide(NP2),and nickel oxide(NP3).Wax-wax interaction of H58⋯H61of n-icosane and wax-solute interaction of hydrogen atom from n-icosane wax and carbonyl oxygen atoms from GS and NPs was investigated via radial distribution function analysis(rdf).The findings revealed that GS/NPs blends have a better chance of wax inhibition than corresponding individuals.Besides that,wax-wax interaction was strongest at 288K,indicating the higher chances of wax formation at low temperature.MD simulation is a promising tool for identifying atoms responsible for the wax formation and inhibition and can be used for chemical wax inhibitor screening for different temperature.