JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2012
·
IF 3.07
Lifang Xu,Zhiqing Zhang,Fang Wang,Dongdong Xie,Shan Yang,Tao Wang,Lijuan Feng,Chengchai Chu
Amphiphilic triblock copolymers of PEO–PPO–PCL with various block compositions have been synthesized by ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) initiated by the OH group of methoxy–poly(ethylene oxide)–poly(propylene oxide) (Me–PEO–PPO). Their structures were confirmed by Fourier transform infrared (FT-IR) measurements, and their self-assembly in aqueous solution was studied using fluorescence spectroscopy, transmission electron microscopy (TEM), UV–vis spectra, differential scanning calorimetry (DSC), and surface tension. For the copolymers studied in this paper, the critical aggregation concentrations (CAC) ranged from 5 × 10 3 to 2 mg/L. The critical micelle concentrations (CMC) decreased with increasing PCL block length, and the downtrend was more significant in the short PCL block length. All of the three copolymers were capable of solubilizing hydrophobic molecules (pyrene) in aqueous solution and copolymers with a longer PCL block exhibited a stronger solubilizing ability. The TEM images showed that the size and morphology of the aggregations could be tuned by varying the compositions or the concentration.
研究领域:
高分子化学
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材料科学
·
胶体与界面化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 3
·1-7
·
IF 1.92
Ji Yanfeng,Kang Wanli,Liu Shuren,Yang Runmei,Fan Haiming
An amphiphilic polymer in water could form an aggregate due to its hydrophobic groups. The rheological properties of the three amphiphilic polymers’ solutions are different because of their different hydrophobic groups. By using a rheometer and a rotatory viscometer, the rheological properties and apparent viscosities of three kinds of amphiphilic polymers have been studied. The results show that all of the polymers are Newtonian fluids at a low shearing rate and pseudoplastic fluids at a high shearing rate. In addition, the amphiphilic polymer-P(AM/BHAM/NaA) has the best thickening behavior and the lowest value of critical aggregation concentration (CAC), which was also verified by fluorescence spectroscopy. By combining creep-recovery with cohesive energy calculation, the structural performance and interaction energy of the aggregate is the reason for the above mentioned phenomenon. By increasing the strength of hydrophobic groups, i.e., with an oil–water partition coefficient, then the structural viscoelasticity of the groups could be improved, and the associate is easily formed in the solution.
研究领域:
高分子化学
·
物理化学
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DOI
高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
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2015
·
IF 2.197
Yan-Ling Luo,Yuan Wang,Xuan Wang,Feng Xu,Ya-Shao Chen
Tribrachia star-shaped random copolymers with tunable thermosensitive phase transition temperature were designed and synthesized via a simple one-pot ammonolysis reaction approach with trimesic acid as cores. The self-assembly micellization behavior of the copolymers in aqueous solution was examined by surface tension, UV–vis transmittance, transmission electron microscope, and dynamic light scattering measurements, etc. The results indicated that the resultant copolymers formed thermosensitive micelle aggregates through hydrophobic interactions among the isopropyl groups of poly(N-isopropylacrylamide) PNIPAM chains and inter-star association at a polymer concentration above critical aggregation concentrations from 4.06 to 6.55 mg L−1, with a cloud point range from 36.6℃ to 52.1℃, and homogeneously distributed micelle size below 200 nm. The arm length and the compositional ratios of the two comonomers had effect on physicochemical properties of the polymer micelle aggregates. Particularly, the cloud point values were enhanced as the (N,N-dimethylacrylamide) DMAM monomer was introduced and reached to 36.6℃ and 41.0℃–44.7℃ when the mass ratio of NIPAM to DMAM was 90:10 and 80:20, respectively. The thermo-triggered drug release and cytotoxicity were evaluated to confirm the applicability of the random copolymer micelle aggregates as novel drug targeted release carriers.
研究领域:
材料科学
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药学
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DOI
高影响因子
Journal of Oleo Science
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2020
·
IF 1.304
TianXu Gao,Chi Ma,Na Wang,Zhuo Guo,Ying Shi,Lee Tin Sin
A novel jellyfish-shaped triazine hexamer quaternary ammonium chloride surfactant (TH12QC) was synthesized, which consisted of one triazine spacer group and six long flexible hydrophobic chains. The molecular structure and aggregation behavior of TH12QC was investigated by nuclear magnetic resonance (NMR), surface tension, electrical conductivity, dynamic light scattering (DLS), transmission electron microscope (TEM), etc. The results show that the jellyfish-shaped TH12QC has better surface activity and lower surface tension than traditional ionic and Gemini surfactants in aqueous solution. There are two inflection points in the curve of conductivity versus concentration of the TH12QC aqueous solution, which correspond to the critical aggregation concentration (CAC) and the critical micelle concentration (CMC) respectively. The existence of CAC indicates that there is a pre-aggregation process before TH12QC forms micelles. The results of DLS and TEM show that network pre-aggregation, spherical aggregation and dense spherical aggregation were observed in different concentration of TH12QC aqueous solution, and the electrostatic equilibrium of the system subtly depends on the concentration of the solution. In addition, intramolecular and intermolecular hydrogen bonding is also an important factor. This study provides a method for studying the aggregation behavior and morphology of oligomeric surfactants with rigid spacer groups.
研究领域:
化学
·
材料科学
·
界面化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2020
·
IF 5.065
Shupeng Zhang,Xiaodong Yang,Zhenbei Tu,Wendong Hua,Penghui He,Haihui Li,Bo Zhang,Tianrui Ren
Polymeric surfactant has explored as an efficient dispersant for improving the physical stability of pesticide suspension concentrate. However, the influence of the hydrophilic monomer on the surface-active property of polymeric surfactant and its application performance in pesticide formulation is rare investigated. Herein, three kinds of random polymers were designed and synthesized via polymerization reaction of styrene (St), methacrylic acid (MAA) with 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HPA) and vinyl sulfonate sodium (VS), respectively. A series of surface-active parameters, including critical aggregation concentration (CMC), saturation surface excess concentration (Γ max ), minimum area per molecule (A min ) and standard Gibbs free energy ΔG m 0 values were obtained from surface tension measurement. The results showed that CMC increased and ΔG m 0 decreased with the increase of the hydrophilicity of the third monomer. The results of foamability measurement indicated that the polymeric surfactant with VS as the third monomer had the best foam producing ability and foam stability. When HPA served as the third monomer, the surfactant had the lowest hydrophile lipophile balance (HLB) value and the O/W emulsion prepared by it had the worst stability. Besides, the influence of synthesized polymeric surfactants as dispersant on zeta potential , viscosity and suspension rate of 430 g/L tebuconazole suspension concentrate were investigated. The results showed that poly(styrene-co-methacrylic acid-co-2-hydroxypropyl acrylate) performed best in improving the physical stability of the formulations. From SEM imagines of tebuconazole particle, it was found the increase of particle size in tebuconazole suspension concentrate were caused by aggregation or Ostwald ripening after thermal storage.
研究领域:
化学工程
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材料科学
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农药科学
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产品关联
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
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2016
·Vol. 69
·期 11
·1254-1260
·
IF 1.427
Jiequn Wu,Tianxiang Yin,Shaoxiong Shi,Weiguo Shen
The systematic investigation of the aggregation behaviours of newly synthesised surface-active ionic liquids 1-alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate ([Cnmim][AOT], n = 2, 3, 5, 6, 7) by various techniques is reported. The critical aggregation concentrations (CACs) and the standard Gibbs free energies of aggregation () were determined from measurements on conductivity, fluorescence, and surface tension, which suggested a stronger self-assembly ability in the bulk solution for [Cnmim][AOT] surfactants with longer alkyl chain cations. An interesting structure transition driven by the penetration of the imidazolium cation into the aggregate when n > 4 was found by analysis of the variations of the values of CAC, , the degree of counter ion binding (β), and the micropolarity (I1/I3) immediately after the CAC with changing alkyl chain length of the imidazolium cation, which was further confirmed by 1H NMR measurements.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Yanyun Bai,Huijun Liu,Xiaoyuan Ma,Xiumei Tai,Wanxu Wang,Zhiping Du,Guoyong Wang
Four glycosyl-modified polysiloxane (GPSO) biosurfactants were designed and synthesized via two-step reactions using green materials. The physicochemical properties: surface activity and aggregation behaviors in aqueous solution were systematically investigated. Investigation of the surface tension indicates that GPSO have relatively low critical aggregation concentrations (CAC) and surface tensions at CAC (γ CAC ) compared with hydrocarbon surfactant. Adsorption at the air-water interface and the formation of micelles in aqueous are spontaneity and the tendencies of adsorption are favored over the process of micellization . Dynamic surface tension results indicate that D-glucoheptono-1, 4-lactone modified polysiloxanes (GHL@Si) have good diffusion ability than that of glucono-δ-lactone modified polysiloxanes (GL@Si). Transmission electron microscopy (TEM) and Dynamic light scattering (DLS) results indicate that part of biosurfactants can form spherical aggregates.
研究领域:
材料科学
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物理化学
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界面科学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2013
·
IF 3.479
Jinlong Yang,Chunmei Gao,Shaoyu Lü,Xinjie Zhang,Chuanming Yu,Mingzhu Liu
Novel amphiphilic polymers (starch–deoxycholic acid, St–DCA) were firstly synthesized on the basis of starch (St) as a hydrophilic segment and deoxycholic acid (DCA) as a hydrophobic segment. Hydrophobically modified starch contained 5.4–8.9 deoxycholic acid groups per 100 anhydroglucose units of starch. Self-aggregates of St–DCA conjugates were formed in the PBS media. Physicochemical characterizations of St–DCA conjugates were investigated. The mean sizes of self-aggregates decreased with the degree of substitution (DS) and pH increasing. Zeta potential indicated that nanoparticles were covered with negatively charged starch shells from −5.4 to −23 mV. TEM images demonstrated that nanoparticles were of spherical shape. The critical aggregation concentrations (cac) were dependent on the DS and pH in the range of 0.0185–0.0441 mg/mL. Thus, the study suggested that self-aggregated nanoparticles of St–DCA conjugates could have good pH-responsive and potential application in pharmaceutical and biomedical fields as the delivery of anti-tumor drugs.
研究领域:
生物材料学
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药剂学
·
生物医学工程
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2015
·
IF 2.515
Yajie Jiang,Tao Geng,Qiuxiao Li,Guojin Li,Hongbin Ju
The equilibrium and dynamic surface tension properties of a series of 1:1 salt-free catanionic surfactants (alkyltrimethylammonium decanoate) were investigated; and, the influence of the length of hydrocarbon chain of cationic part (carbon number of 10, 12, 14, 16, 18, respectively) on the surface properties was discussed. The plot of the logarithm of the critical aggregation concentration (cac) against the carbon number showed a linear decrease with an increase in chain length. On the basis of the slope of this plot, it was found that the variation of cac with the chain length is smaller for salt-free catanionic surfactants (C + n –C − 10 ) than that for single anionic or cationic surfactants. The surface tension at the cac was quite low, much lower than that of single cationic or anionic surfactants at cmc. At dilute surfactant concentration, the adsorption process is diffusion-controlled adsorption; at higher concentration (above cac), it became the mixed diffusion-kinetic mechanism. The diffusion rate of the monomer for the salt-free catanionic surfactants was lower than that of conventional cationic or anionic surfactants, due to a larger molecular size. Furthermore, it was confirmed that the kinetic energy of adsorption at the gas/solution interface decreased with an increase in the hydrocarbon chain length.
研究领域:
物理化学
·
表面科学
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2018
·Vol. 296
·期 2
·335-340
·
IF 1.967
Hu Chang,Du Zhiping,Tai Xiumei,Mao Xuebin,Liu Xiaoying
In this paper, the physicochemical properties between sodium dodecylbenzenesulfonate (SDBS) and polyvinylpyrrolidone (PVP) in aqueous solutions were studied at 25 °C by Ubbelohde viscometer, conductivity analyzer, and fluorescence spectrophotometer. It was found that viscosity, conductivity, steady-state fluorescence, and Rayleigh scattering curve for SDBS-PVP system could be divided into three regions by two characteristic concentrations: the critical aggregation concentration (cac) and the polymer saturation point (psp). The results revealed that interactions between SDBS and PVP molecules in aqueous solutions could be explained by “necklace and bead” model. Micelle-like surfactant aggregates, formed by SDBS-free molecules, associated with PVP chains mainly by hydrophobic interaction.
研究领域:
物理化学
·
表面活性剂科学
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 18
·15175-15179
·
IF 3.289
Rui-Juan Shi,Yong Chen,Xiao-Fang Hou,Yu Liu
The molecular induced aggregation behaviors of a polycationic cyclodextrin, i.e. per-6-deoxy-6-(1-methylimidazol-3-ium-3-yl)-β-cyclodextrin (1), towards five anionic surfactants, i.e. sodium decyl sulfonate (SDES), sodium undecyl sulfonate (SUS), sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS) and sodium dodecyl benzene sulfonate (SDBS), were comprehensively investigated in aqueous solution. The results showed that the introduction of 1 could efficiently decrease the critical aggregation concentrations (CAC) of the selected surfactants by a factor of 14–467, leading to the formation of nanoscale spherical particles with a diameter of 200–400 nm and nearly neutral or moderate positive zeta potential. Significantly, the resultant 1/SLS and 1/SDBS aggregates exhibited the ability of loading both anionic and neutral model substrates.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 90
·87461-87468
·
IF 3.289
Qing Ge,Dingshuo Lou,Shui Lu,Wei Zhang,Li Zhang,Xinping Wang
Poly(ionic liquid)s (PILs) have promising potential to form assemblies with ordered structures in organic media, but experimental investigation on the detailed aggregation behavior of PILs has seldom been involved. In this study, a series of N-alkyl imidazolium-based PILs with different chemical composition in their n-propanol solution was investigated by conductivity measurements. TEM images indicate that PILs with long alkyl chains exhibit onion-like multilamellar structures. The thermodynamic parameters suggest that aggregation of PILs in their good solvents (n-PrOH) is spontaneous, driven by entropy change associated with a hydrophobic effect. As increasing alkyl chain length from 8 to 16, the contribution of per alkyl chain to ΔGθm for PIL aggregation is found to decrease by more than 2 times. The nonsolvent (H2O) contribution to change of Gibbs free energy as well as critical aggregation concentration (CAC) decrease linearly with the volume fraction of water in mixed solvents, implying that PIL aggregation becomes more favorable with the addition of nonsolvent. The results mentioned above play an important role in understanding the aggregation process of PIL in an organic solvent and developing functional materials with well-ordered structures.
研究领域:
高分子化学
·
胶体与界面化学
·
物理化学
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）