Browsing by Author "Liao, Chun-Syong"

Now showing 1 - 6 of 6

Fabrication of Patterned Superhydrophobic Polybenzoxazine Hybrid Surfaces
(2009-03-17)
Liao, Chun-Syong
;
Wang, Chih-Feng
;
Lin, Han-Ching
;
Chou, Hsin-Yi
;
Chang, Feng-Chih
The hydrophilicity of bis(3-allyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane(B-ala) polybenzoxazine film and superhydrophobic polybenzoxazine-hybrid surface can be controlled through UV exposure to change the ratio of intra to intermolecular hydrogen bonds. A fraction of the intramolecular hydrogen bonding of the as-cured sample will convert into intermolecular hydrogen bonding upon UV exposure and thus results in an increase of hydrophilicity. This simple method allows for manipulating the hydrophilicity at selected regions on a superhydrophobic polybenzoxazine hybrid surface to create a patterned surface with superhydrophobic and superhydrophilic regions. Additionally, we have found that the superhydrophobic polybenzoxazine-silica hybrid surface exhibits good adhesion of water droplets after UV exposure, which can be served as a "mechanical hand" to transfer water droplets from a superhydrophobic surface to a hydrophilic one.
Modification of polymer substrates with low surface free energy material by low-temperature cured polybenzoxazine
(2008-01-02)
Liao, Chun-Syong
;
Wu, Jiann-Shing
;
Wang, Chih-Feng
;
Chang, Feng-Chih
;
應用化學系
The B-ala/AIBN PBZ system has a high extent of ring-opening of oxazine because phenol-containing oligomers are formed at the early stage of the curing process. As a result, the B-ala/AIBN PBZ system possesses a relatively stronger intramolecular hydrogen bonding and lower surface energy than the pure B-ala system at low temperature curing. In this context, poly(4-vinyl pyridine), poly(4-vinyl phenol) thin films and polycarbonate substrates, which lack liquid resistance, possess low surface free energy after modification with B-ala/AIBN = 5/1 PBZ.
New approach to fabricate an extremely super-amphiphobic surface based on fluorinated silica nanoparticles
(2008-09-15)
Sheen, Yuung-Ching
;
Huang, Yuan-Chang
;
Liao, Chun-Syong
;
Chou, Hisn-Yi
;
Chang, Feng-Chih
Superoleophobic surfaces possessing static contact angles greater than 140 degrees with organic liquids are extremely rare. A simple approach has been developed to fabricate an extremely superamphiphobic coating material based on fluorinated silica nanoparticles resulting contact angles of water and diiodomethane at 167.5 degrees and 158.6 degrees, respectively. The contact angle of diiodomethane at 158.6 degrees is substantially higher than the highest literature reported value we know of at 110 degrees. In addition, this developed film also possesses extremely high contact angles with other organic liquids such as soybean oil (146.6 degrees), decahysronaphthalene (142.5 degrees), diesel fuel (140.4 degrees), and xylene (140.5 degrees). This developed superamphiphobic organic-inorganic hybrid film possesses unique liquid repellency for both water and organic liquids that can be used as functional coatings on numerous substrates by a simple coating process. (C) 2008 Wiley Periodicals, Inc.
Self-assembly behavior of A-B diblock and C-D random copolymer mixtures in the solution state through mediated hydrogen bonding
(2008-08-05)
Hsu, Chih-Hao
;
Kuo, Shiao-Wei
;
Chen, Jem-Kun
;
Ko, Fu-Hsiang
;
Liao, Chun-Syong
We have synthesized poly(methyl methacrylate-b-4-vinylpyridine) (PMMA-b-P4VP) and poly (styrene-r-vinylphenol) (PS-r-PVPh) copolymers by using anionic and free radical polymerizations, respectively. Well-defined micelles through hydrogen bonding have been prepared by mixing PMMA-b-P4VP diblock copolymer and PS-r-PVPh random copolymer in a single solvent. Block copolymers were mixed with random copolymers, with various [N]/[OH] ratios (4/1, 2/1, 1/1, and 1/4) in which "[N]/[OH]" represents the molar ratio of pyridine groups on P4VP to hydroxyl groups on PVPh. The presence distribution of PVPh/P4VP and PVPh/PMMA hydrogen bonding depends on the feeding ratio of PVPh to P4VP. When the PVPh content is lower than that of P4VP, hydrogen bonding occurs only between PVPh and P4VP; with excess PVPh, additional hydrogen bonding between PVPh and PMMA would occur. Furthermore, the effect of the solvent quality on the self-assembly behavior of PMMA-b-P4VP/PS-r-PVPh blends is investigated by considering tetrahydrofuran (THF) and dimethylformamide (DMF) as common solvents. We can mediate the strength of hydrogen bonding in blend systems by adopting different solvents and inducing different morphology transitions.
Syntheses, Specific Interactions, and pH-Sensitive Micellization Behavior of Poly [vinylphenol-b-2-(dimethylamino)ethyl methacrylate] Diblock Copolymers
(2008-11-25)
Chen, Shih-Chien
;
Kuo, Shiao-Wei
;
Liao, Chun-Syong
;
Chang, Feng-Chih
;
應用化學系
We have used anionic polymerization to prepare a series of poly [vinylphenol-b-2(dimethylamino)ethyl methacrylate] (PVPh-b-PDMAEMA) block copolymers. These block copolymers are miscible, with strong specific interactions occurring between the OH groups of the PVPh segments and the tertiary ammonium groups of the PDMAEMA segments. These PVPh-b-PDMAEMA diblock copolymers exhibit higher glass transition temperatures than do the corresponding PVPh/partially protonated PDMAEMA blends obtained from DMSO solution, which we suspect exist in the form of separate coils. The blocks of the PVPh-b-PDMAEMA diblock copolymers interact strongly, resulting in polymer complex aggregation similar to the behavior of PVPh/partially protonated PDMAEMA blend complexes obtained from methanol solution. The spin-lattice relaxation times in the rotating frame, determined through solid state NMR spectroscopic analysis, provided clear evidence that the polymer complex aggregates formed from the diblock copolymers have shorter values of TV, than do the corresponding separated coils in the miscible blends. In addition, these PVPh-b-PDMAEMA diblock copolymers exhibit a novel type of pH sensitivity: at low pH, compact spherical micelles are formed possessing PDMAEMA coronas and PVPh cores; at medium pH, vesicles are observed, consisting of partially protonated hydrophilic PDMAEMA shells and hydrophobic PVPh cores; at high pH, the spherical micelles that formed comprised ionized PVPh coronas and deprotonated hydrated-PDMAEMA cores, i.e., phase inversion of the micelles formed at pH 2.
Tuning the Surface Free Energy of Polybenzoxazine Thin Films
(2008-10-01)
Liao, Chun-Syong
;
Wang, Chih-Feng
;
Lin, Han-Ching
;
Chou, Hsin-Yi
;
Chang, Feng-Chih
A novel approach to manipulate the surface free energy and wettability on polybenzoxazine thin films can be achieved simply by varying the time of thermal treatment or UV exposure. A fraction of the intramolecular hydrogen bonding of the as-cured sample will convert into intermolecular hydrogen bonding upon thermal treatment or UV exposure and, thus, results in an increase in the hydrophilicity and wettability. This UV approach provides a simple method to generate wettability patterns or wettability gradients on the surface of a polybenzoxazine film. In addition, we have applied this technique to the preparation of a large-area periodic array of CdTe colloidal nanocrystals on polybenzoxazine thin films.