董金凤
以表面活性剂为典型的双亲分子的物化性能、在界面的吸附、溶液中的有序自组装行为以及双亲分子在现代药物传递和环境科学中的应用。
个性化签名
- 姓名:董金凤
- 目前身份:
- 担任导师情况:
- 学位:
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学术头衔:
博士生导师
- 职称:-
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学科领域:
物理化学
- 研究兴趣:以表面活性剂为典型的双亲分子的物化性能、在界面的吸附、溶液中的有序自组装行为以及双亲分子在现代药物传递和环境科学中的应用。
董金凤
专业方向:化学 物理化学
教育与研究经历
1994. 10 –1995. 9: 访问学者, Bristol University, UK
1995. 10 –1999.3: 博士,Hull University, UK.
1999. 9 –2002. 9: Research Fellow, the University of Greenwich.
2003.3 –: 武汉大学化学与分子科学学院,教授,博士生导师。
研究领域与兴趣
以表面活性剂为典型的双亲分子的物化性能、在界面的吸附、溶液中的有序自组装行为以及双亲分子在现代药物传递和环境科学中的应用
教学情况
2003年至今,讲授化学院物理化学专业研究生课《两亲分子有序自组装体系》;
2003年至今,主讲化学院本科生课程《胶体与界面化学》;
2006 年至今,讲授化学院本科生课程《当代化学之》之《表面活性剂在高技术中的应用》;2006 年至今,讲授化学院物理化学专业研究生课程《物理化学前沿》之《胶体与界面科学》。
承担项目与课题
国家科技部“十一五”科技支撑计划子课题“农药创制工程-农药助剂-替代苯类有机溶剂的绿色溶剂开发”;
国家科技部“十五”科技攻关计划滚动项目课题“自乳化型农药微乳化新剂型及其助剂的开发”;
国家自然科学基金面上项目“自乳化、自转型农药新剂型的形成机理”;
国家自然科学基金面上项目“含吡咯环Gemini表面活性剂聚集行为及聚集体结构转变机理研究”;
湖北省科技攻关项目“新型消毒剂的开发”;
教育部回国留学人员基金“有机污染土壤的物理化学修复”;
中国石油长庆勘探研究院“特低渗透储层岩石、原油、水之间界面微观特性的实验研究”。
学术兼职
1. Colloid and Polymer Science (Springer)中国地区主编;
2. 中国化学会胶体与界面专业委员会委员。
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4
董金凤, J INGFENGDONG, † B ABURCHOWDHRY, ‡AND S TEPHENLEHARNE*, ‡
Environ. Sci. Technol. 2004, 38, 594-602,-0001,():
-1年11月30日
The removal of dense nonaqueous phase liquid mixtures (DNAPLs) from rocks and subsurface soils is an ongoing remedial challenge. Very often the wetting preferences of the system are not altered by exposure to the DNAPL. However, there are systems where the wetting properties of the solid phase have been altered from strongly water wetting by exposure to the DNAPL. In these cases some technique is necessary for reducing the work of adhesion between the DNAPL and the mineral surface. The focus of this report is the problems posed by coal tar in unconsolidated sands. It is shown that coal tar can alter the wetting properties of quartz, the principal component of sands, and is thus capable of adhering to the surface. In this investigation the ability of several members of the poloxamine family of polymeric surfactants to aid in the removal of coal tar from sand was evaluated. The poloxamines are tetrafunctional block copolymeric surfactants, which contain four poly(ethylene oxide)-block-poly(propylene oxide) chains joined to a central ethylenediamine moiety via the nitrogen atoms. Contact angle measurements of coal tar on a quartz surface immersed in aqueous surfactant solution and the interfacial tension between coal tar and aqueous surfactant solution have been measured. Coal tar/water interfacial tensions are reduced to values in the region of 2 mN m-1 at surfactant concentrations of approximately 0.1 w/v %. Poloxamine surfactant impact on the static contact angle is more complex. In some cases the polymeric surfactants alter the wetting behavior from strongly water wetting to weakly water wetting. However, other poloxamines appear to have little if any impact on the contact angle, which remains strongly water wetting. The foregoing measurements have then been used to calculate the work of adhesion of the coal tar to quartz and the results qualitatively compared with the concentration of surfactant solution required to visually demonstrate the complete de-adhesion of coal tar to the quartz. It is shown that at surfactant concentrations below the critical micelle concentration (cmc) of the surfactant, the work of adhesion can be reduced sufficiently to ensure complete removal of coal tar from both quartz and sand.
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【期刊论文】Solubilisation of polyaromatic hydrocarbons in aqueous solutions of poloxamine T803
董金凤, Jinfeng Donga, Babur Z. Chowdhryb, Stephen A. Leharneb, ∗
Colloids and Surfaces A: Physicochem. Eng. Aspects 246 (2004) 91-98,-0001,():
-1年11月30日
The solubilisation of exemplar polyaromatic hydrocarbons (PAHs) in aqueous solutions of the block co-polymeric surfactant T803 has been investigated. The PAHs used were naphthalene, phenanthrene and pyrene. T803 is a tetrafunctional block co-polymer derived by way of the coupling of ethylene oxide and propylene oxide to ethylene diamine. The presence of the ethylene diamine moiety provides the compound with pH functionality. In particular, micellisation in these systems is shown to be pH dependent. As a consequence, solubilisation in T803 solutions is also shown herein to be pH dependent, giving rise to considerable changes in the apparent aqueous solubilities of the PAHs. A switch in pH from 4 to 10.3 changes the apparent aqueous solubility of naphthalene, phenanthrene and pyrene by one, two and three orders of magnitude, respectively. Likewise, changes in temperature from 25 to 40 ◦C also produce changes of similar orders of magnitude in the apparent aqueous solubilities of phenanthrene and pyrene at a pH of 5.6 and T803 concentration of 5 mM.
Ethylene oxide-propylene oxide block copolymers, Solubilisation, Poly aromatic hydrocarbons, pH and temperature effects, Poloxamines
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董金凤, Jingfeng Donga, Jonathan Armstrong b, Babur Z. Chowdhry c, d, Stephen A. Leharne d, e, ∗
Thermochimica Acta 417 (2004) 201-206,-0001,():
-1年11月30日
Differential scanning calorimetry has been used to investigate the effect of pH upon the temperature interval over which aggregation occurs in aqueous solutions of the ethylene oxide (EO)/propylene oxide (PO) block co-polymeric compound tetronic T701 (molecular formula EO4PO13)2NCH2CH2N(PO13EO4)2). Self association, in this system, occurs at elevated temperatures because the PO blocks become increasingly non-polar and, as a consequence, self associate because of the hydrophobic effect. pH titration shows that the central ethylene diamine moiety is di-basic with pKa values of 3.8 and 8. Thus, in aqueous solution when the pH value is below 8 a necessary pre-condition for self association is deprotonation. A theoretical model is developed-based upon this hypothesis-which attempts to replicate, with some success, the effect of pH upon the calorimetrically observed T701 self association process.
Poloxamine, Co-polymer, Calorimetry, pH titration, pKa, Self association
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【期刊论文】Surface activity of poloxamines at the interfaces betweenair-water and hexane-water
董金凤, Jingfeng Dong a, Babur Z. Chowdhry b, c, Stephen A. Leharne a,
Colloids and Surfaces A: Physicochem. Eng. Aspects 212 (2003) 9-17,-0001,():
-1年11月30日
Poloxamines are tetra functional block copolymers, which contain four polyethylene oxide (PEO)-polypropylene oxide (PPO) chains joined to a central ethylene diamine moiety by way of the nitrogen atoms. Surface and interfacial tensions at the air-water and hexane-water interfaces have been determined over a wide concentration range for several of these block copolymeric amphiphiles. Titration data indicates that these molecules are dibasic. Two pKa values-corresponding to proton loss from the central nitrogen atoms of the molecule-have been determined by fitting titrimetric data to a thermodynamic model of the titration process. The values obtained are fairly constant for different poloxamines, which suggests that varying the block size has little impact upon these pKa values. However, the values obtained are lower than those observed for ethylene diamine and indicate that the attachment of the PEO-PPO chains to the nitrogen atoms does reduce their basicity. The Gibbs adsorption isotherm at the air-water interface is similar to the adsorption pattern reported for the poloxamers-linear PEO-PPO-PEO block copolymers [Langmuir 10 (1994) 2604] and shows that the highly branched poloxamines have similar interfacial properties as the poloxamers. Data is also reported on adsorption of poloxamines at the hexane-water interface. In the main it is concluded that those block copolymers with high PPO to PEO ratios and which are, therefore, relatively hydrophobic are more effective in reducing surface and interfacial tensions. These effects are, however, attenuated by changes in aqueous phase pH, which alters the charged nature of the poloxamine molecule.
Poloxamines, Adsorption, Surface tension, Hexane-water interfacial tension, Effectiveness of surface tension reduction
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