Research Topic

Wetting Transition in Surfactant Systems

We are interested in the interfacial behaviors in the region of three coexisting liquid phases of the system water + oil + surfactant. We have found a particular surfactant system for which the middle phase exhibits a sequence of wetting transition: nonwetting → partial wetting → complete wetting, at the interface between the upper and lower phases by simply varying temperature. We are currently trying to understand the molecular mechanism responsible for this remarkable phenomenon by using density functional theory. Application of this research can be widely found in detergency, cosmetics, enhanced oil recovery, food industry, pharmaceutics, fabrics, etc.  

Molecular Simulations

Molecular dynamics, a technique of molecular simulations, involves solving Newton's equations of motion for hundreds up to million molecules to gain the trajectories of molecules moving in an imaginary box. These trajectories provide information about the thermodynamic and structural properties microscopically that cannot be obtained experimentally for realistic fluids. We apply this technique to understand the hydrogen bonding effects on the phase behaviors and to calculate the diffusivity of small molecules in silicalite.

Recent Research Topic

Honor

The Representative Publication All Publication

1. Ming-Chih Yeh, Ping-Chang Lin, and Li-Jen Chen, 2004, “Effect of Molecular Structure on Wetting Behavior at the Air-Liquid Interface of Water + Alcohol Mixtures,” J. Phys. Chem. B 108, 9955-9961. (SCI, EI)

2. Ming-Chih Yeh, Chia-Ming Chen, and Li-Jen Chen, 2004, “Effect of Hydrophobicity of Amphiphile on Wetting Behaviors of Ternary Water + Oil + Amphiphile Mixtures: A Density Functional Theory Approach,” J. Phys. Chem. B 108, 7271-7279. (SCI, EI)

3. Da-Ren Chiou and Li-Jen Chen, 2004, “Liquid-liquid equilibria for the ternary system water + diethylene glycol monohexyl ether + 2-methyl-2-butanol,” Fluid Phase Equilibria, 218, 229-234. (SCI, EI)

4. Bo-Jiun Lin and Li-Jen Chen, 2004, “Liquid-liquid equilibria for the ternary system water + tetradecane + 2-butyloxyethanol,” Fluid Phase Equilibria 216, 13-20. (SCI, EI)

5. Li-Jen Chen, Yih-Heh Sheu, and Pei-Juian Li, 2004, “Heat Capacity Changes Accompanying Micelle Formation upon Burial of Hydrophobic Tail of Non-ionic Surfactants,” J. Phys. Chem. B, 108, 19096-19098. (SCI, EI)

6. Chih-Kang Wu and Li-Jen Chen, 2005, “Observation of a sequence of wetting transitions in the binary water + ethylene glycol monobutyl ether mixture,” J. Chem. Phys. 123(8), 084506. (SCI, EI)

7. Chih-Kang Wu and Li-Jen Chen, 2005, “Wetting Behavior of Water + CiEj Mixtures: an Experimental Study,” Langmuir 21, 6883-6890. (SCI, EI)

8. Su, I.-F., L.-J. Chen and S.-Y. Suen, 2005, “Adsorption Separation of Terpene Lactones from Ginkgo Biloba L. Extract Using Glass Fiber Membranes Modified with Octadecyltrichlorosilane,” Journal of Separation Science 28, 1211-1220. (SCI)

9. Chih-Kang Wu and Li-Jen Chen, 2006, “The pressure- and temperature induced wetting transitions in the binary water + ethylene glycol monoisobutyl ether mixture,“ J. Phys. Chem. B, 110, 11907-11911. (SCI, EI)

10. Bo-Jiun Lin and Li-Jen Chen, 2006, “Phase transitions in two-dimensional colloidal particle system observed in Langmuir trough,” Colloids and Surfaces A, Vol 284-285C, pp 239-245. (SCI, EI)

11. Da-Ren Chiou, Kuan-Yu Yeh, and Li-Jen Chen, 2006, “Adjustable pretilt angle of nematic 4-n-pentyl-4'-cyanobiphenyl on self-assembled monolayers formed from organosilanes on square-wave grating silica surfaces,“ Applied Physics Letters 88, 133123. (SCI, EI)

12. Chia-Ming Chen, Ming-Chih Yeh, and Li-Jen Chen, 2006, "Bulk and Interfacial Wetting Behavior of Binary Mixtures Induced by Associating Between Unlike Pair Molecules," J. Phys. Chem. B 110, 3294-3301. (SCI, EI)

13. Da-Ren Chiou, Li-Jen Chen, and Chein-Dhau Lee, 2006, “Liquid crystal alignment and pretilt angle of liquid crystals on micro-grooved polyimide surfaces fabricated by soft embossing method,” Langmuir, 22, 9403-9408. (SCI, EI)Bo-Jiun Lin and Li-Jen Chen, 2007, “Phase transitions in two-dimensional colloidal particles at oil/water interfaces,” Journal of Chemical Physics 126, 034706. (SCI, EI)

14. Chih-Hao Hsu, Ming-Chih Yeh, Kung-Lung Lo and Li-Jen Chen, 2007, “Application of Microcontact Printing to Electroless Plating for the Fabrication of Microscale Silver Patterns on Glass,” Langmuir 23, 12111-12118. (SCI, EI)

15. Kuan-Yu Yeh, Li-Jen Chen and Jeng-Yang Chang, 2008, “Contact angle hysteresis on regular pillar-like hydrophobic surfaces,” Langmuir 24, 245-251. (SCI, EI)

16. Hung-Wei Tsui, Ya-Huei Hsu, Jing-Han Wang, and Li-Jen Chen, 2008, “Novel behavior of heat of micellization of Pluronics F68 and F88 in aqueous solutions,” Langmuir 24, 13858-13862. (SCI, EI)

17. Ming-Chih Yeh, Chia-Ming Chen and Li-Jen Chen, 2008, “Effect of molecular structure on wetting behavior of water + amphiphile mixtures:  A density functional approach,” Journal of Chemical Physics 128(4), 044719. (SCI, EI)

18. Wei-Fan Kuan and Li-Jen Chen, 2009, “Preparation of superhydrophobic surfaces of a hierarchical silicon nanowire structure,” Nanotechnology, 20, 035605. (SCI, EI)