Browsing by Author "Lin, I-Hong"

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Molecular recognition within a poly(amide urethane) system
(1970-01-01)
Yen, Ying-Chieh
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Cheng, Chih-Chia
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Tsai, Jia-You
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Lin, I-Hong
;
Wang, Yeh-Sheng
"The heterodimer recognition within a poly(amide urethane) (PAU) has been achieved through the incorporation of the amphiphilic alkylated nucleobase, 1-hexadecyluracil (U16). The heterodimer recognition led the poly(amide urethane) to exhibit the ""plug and play"" behavior even the heterodimer recognition coincided with several other hydrogen bonding motifs. In addition, the PAU/U16 blends possess nano-scale lamellar structure of U16 phase within lamellar structure of PAU phase. The nano-scale lamellar structure of the packed U16 gradually transforms from one to the other with the change in the U16 content in the blends. (C) 2012 Elsevier Ltd. All rights reserved."
New self-assembled supramolecular polymers formed by self-complementary sextuple hydrogen bond motifs
(2012)
Cheng, Chih-Chia
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Lin, I-Hong
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Yen, Ying-Chieh
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Chu, Chih-Wei
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Ko, Fu-Hsiang
A new supramolecular material, N-(6-(3-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl) propanamido)pyridin-2-yl)undec-10-enamide (U-DPy) possesses an extremely high association constant (K-a > 10(7) M-1), which is able to dimerize through a self-complementary sextuple hydrogen-bonding array. As the end groups of an oligomer, U-DPy forms a self-assembling polymer system. These new mono- and difunctional telechelic supramolecular polymers have highly prominent properties, leading to a substantial increase in viscosity, thermal stability and unique morphology changes in the solid state. More surprisingly, they can self-organize into lamellar crystallization and a spherical structure. In addition, upon increasing the concentration in the solution state, the size of the resulting spherical structure is gradually increased. These spherical structures are constructed from supramolecular polymers with a high degree of polymerization.
Nucleobase-Functionalized Supramolecular Micelles with Tunable Physical Properties for Efficient Controlled Drug Release
(2016-10)
Cheng, Chih-Chia
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Lin, I-Hong
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Chen, Jem-Kun
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Liao, Zhi-Sheng
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Huang, Jyun-Jie
Complementary nucleobase-functionalized polymeric micelles, a combination of adenine-thymine (A-U) base pairs and a blend of hydrophilic-hydrophobic polymer pairs, can be used to construct 3D supramolecular polymer networks; these micelles exhibit excellent self-assembly ability in aqueous solution, rapid pH-responsiveness, high drug loading capacity, and triggerable drug release. In this study, a multi-uracil functionalized poly(epsilon-caprolactone) (U-PCL) and adenine end-capped difunctional oligomeric poly(ethylene glycol) (BA-PEG) are successfully developed and show high affinity and specific recognition in solution owing to dynamically reversible A-U-induced formation of physical cross-links. The U-PCL/BA-PEG blend system produces supramolecular micelles that can be readily adjusted to provide the desired critical micellization concentration, particle size, and stability. Importantly, in vitro release studies show that doxorubicin (DOX)-loaded micelles exhibit excellent DOX-encapsulated stability under physiological conditions. When the pH value of the solution is reduced from 7.4 to 5.0, DOX-loaded micelles can be rapidly triggered to release encapsulated DOX, suggesting these polymeric micelles represent promising candidate pH-responsive nanocarriers for controlled-release drug delivery and pharmaceutical applications.
Self-Assembly structures through competitive interactions of miscible crystalline-amorphous diblock copolymer/homopolymer blends
(2009-10-20)
Lin, I-Hong
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Kuo, Shiao-Wei
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Chang, Feng-Chih
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應用化學系
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Department of Applied Chemistry
A series of miscible crystalline-amorphous diblock copolymers, (poly(epsilon-caprolactone)-b-(vinyl phenol), PCL-b-PVPh) were prepared through sequential ring-opening and controlled living free radical (nitroxide-mediated) polymerizations and then blended with poly(vinyl pyrrolidone) (PVP) homopolymer. Specific interactions, miscibility, and self-assembly morphologies mediated by hydrogen bonding interactions of this new A-B/C type blend, were investigated in detail. Micro-phase separation of these miscible PCL-b-PVPh diblock copolymers occurs by blending with PVP through competitive hydrogen bonding interaction in this A-B/C blend. FTIR, XRD, and DSC analyses provide positive evidences that the carbonyl group of PVP is a significantly stronger hydrogen bond acceptor than PCL, thus the PCL block is excluded from the PVPh/PVP miscible phase to form self-assembly structure. (13)C CP/MAS solid-state NMR spectra provide additional evidence confirming that micro-phase separation occurs in the blend system because of the presence of more than two T(1p)(H) values for this A-B/C blend system. According to the result of the FTIR and SAXS results, the smaller molecular weight system contains a greater fraction of the hydrogen-bonded carbonyl group, cause indirectly the high degree of phase separation among these blends. In addition, the SAXS profiles possess a sharp primary peak and highly long range ordered reflections q/q* ratios of 1:2:3 at lower PVP content, an indication of the lamellar structure in the blend which is consistent with TEM image. The phase behavior and morphology shifts from lamellar to cylinder structure with further increase in the PVP content. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis and Assembly Behavior of Heteronucleobase-Functionalized Poly(epsilon-caprolactone)
(2010-02-09)
Lin, I-Hong
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Cheng, Chih-Chia
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Yen, Ying-Chieh
;
Chang, Feng-Chih
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應用化學系
The heteronucleobase (adenine and uracil)-functionalized poly(epsilon-caprolactone) (A-PCL-U) possessing supramolecular structure has been successfully synthesized through the combination of ring-opening polymerization and Michael addition reaction. Attachment of multiple hydrogen-bonding units to chain ends of PCL results in phase separation and substantial increase in the viscosity. The association constant (K(a)) between adenine and uracil groups of A-PCL-U calculated from NMR measurement is 18.9 M(-1). XRD and DSC analyses indicate that the crystalline structure of the A-PCL-U is changed to some extent due to phase segregation as compared to the PCL homopolymer. The AFM micrograph demonstrates that phase segregation is formed from the hard nucleobase chain ends and soft poly(epsilon-caprolactone) chains of the supramolecular complex.