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
The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo)phenoxy]alkyl...The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo)phenoxy]alkyl methacrylates with varying methylene groups (n = 0, 2, 6) were used to synthesize a series of azobenzene-containing amphiphilic triblock copolymers PAnC–PEG–PAnC by atom transfer radical polymerization (ATRP). Differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and one-dimensional X-ray diffraction (1D WAXD) have shown that the glass transition temperatures of these copolymers decreased with increasing n, PA0C–PEG–PA0C has no mesophase, while both PA2C–PEG–PA2C and PA6C–PEG–PA6C have a nematic mesophase. These differences derive from the length of spacer groups between the polymer backbone and side-chain LC monomers.展开更多
A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of poly...A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol containing sulfur. These chelating resins were found to show high adsorption capacities for Ag^＋, Hg^2＋, Au^3＋ and Pd^2＋, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.展开更多
In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses...In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses subgroup in Drosophila immigrans species group and D.hydei which was selected as outgroup were acquired. Phylogenetic trees were reconstructed using maximum parsimony,maximum likelihood,neighbor joining and Bayesian methods based on H2a-H2b and Cyt b DNA sequences. The results indicated that Drosophila curviceps species subgroup is located at the base of molecular trees, diverged first in this group; the second clade is Drosophila quadrilineata species subgroup; the third is Drosophila hypocausta species subgroup; the fourth is Drosophila immigrans species subgroup; Drosophila nasuta species subgroup is the last diverged clade. Moreover,the phylogentic relationships of seven specieses in Drosophila nasuta subgroup was investigated.展开更多
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.
文摘The effect of flexible spacer length on the liquid crystalline property of ABA-type triblock copolymers containing azobenzene groups was investigated. For the study, the monomers, n-[4-(4-ethoxyphenylazo)phenoxy]alkyl methacrylates with varying methylene groups (n = 0, 2, 6) were used to synthesize a series of azobenzene-containing amphiphilic triblock copolymers PAnC–PEG–PAnC by atom transfer radical polymerization (ATRP). Differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and one-dimensional X-ray diffraction (1D WAXD) have shown that the glass transition temperatures of these copolymers decreased with increasing n, PA0C–PEG–PA0C has no mesophase, while both PA2C–PEG–PA2C and PA6C–PEG–PA6C have a nematic mesophase. These differences derive from the length of spacer groups between the polymer backbone and side-chain LC monomers.
基金The authors are grateful to the financial support by the Postdoctoral Science Foundation of China(No.2003034330)the Science Foundation for mid-youth elite of Shangdong Province+1 种基金the Natural Science Foundation of Shangdong Province(No.Q99B15)the National Natural Science Foundation of China(No.2906008)
文摘A series of new chelating resins with incorporating heterocyclic functional groups： pyridine, thiadizole, benzothizole into macroporous chloromethylated polystyrene were synthesized via hydrophilic spacer arm of polyethylene glycol containing sulfur. These chelating resins were found to show high adsorption capacities for Ag^＋, Hg^2＋, Au^3＋ and Pd^2＋, and the presence of spacer arm can enhance adsorption ability due to increase the hydrophilicity of the chelating resins.
文摘In order to investigate molecular phylogenetic relationships of Drosophila immigransspecies group,nucleotide sequences of H2a-H2b spacer regions and partial nucleotide sequences of Cytochrome b gene for five specieses subgroup in Drosophila immigrans species group and D.hydei which was selected as outgroup were acquired. Phylogenetic trees were reconstructed using maximum parsimony,maximum likelihood,neighbor joining and Bayesian methods based on H2a-H2b and Cyt b DNA sequences. The results indicated that Drosophila curviceps species subgroup is located at the base of molecular trees, diverged first in this group; the second clade is Drosophila quadrilineata species subgroup; the third is Drosophila hypocausta species subgroup; the fourth is Drosophila immigrans species subgroup; Drosophila nasuta species subgroup is the last diverged clade. Moreover,the phylogentic relationships of seven specieses in Drosophila nasuta subgroup was investigated.
