Ying-Chieh Yen

Miscibility and Hydrogen-Bonding Behavior in Organic/Inorganic Polymer Hybrids Containing Octaphenol Polyhedral Oligomeric Silsesquioxane

In this study, we investigated the miscibility behavior and mechanism of interaction of poly(methyl mechacrylate) (PMMA), poly(vinyl pyrrolidone) PVP, and PMMA- co-PVP blends with octa(phenol)octasilsequioxane (OP-POSS). For the PMMA/OP-POSS binary blend, the value of the association constant ( K A = 29) was smaller than that in the poly(vinyl phenol) (PVPh)/PMMA ( K A = 37.4) and ethyl phenol (EPh)/PMMA ( K A = 101) blend systems, implying that the phenol groups of the OP-POSS units in the PMMA/OP-POSS blends interacted to a lesser degree with the CO groups of PMMA than they did in the other two systems. In addition, the ionic conductivity of a LiClO4/PMMA- co-PVP polymer electrolyte was increased after blending with OP-POSS.

A New Supramolecular Hole Injection/Transport Material on Conducting Polymer for Application in Light-Emitting Diodes

A new DNA-mimetic π-conjugated polymer poly(triphenylamine-carbazole) (PTC-U) has been prepared which exhibits high thermal stability, non-corrosion, excellent hole injection and electron-blocking abilities in the solid state owing to the uracil induced physical cross-linking. In addition, a trilayer device with PTC-U as a hole injection/transport layer is approximately 1.6 times higher than that of the commercial product PEDOT:PSS-based devices.

A new supramolecular POSS electroluminescent material

A new polyhedral oligomeric silsesquioxane (POSS) core star-like supramolecular blue-light electroluminescent material, 4-uracilbutyl-1-methylpyrene ether (U-PY)/octakis[dimethyl(N-(6-acetamidopyridin-2 yl))siloxy] silsesquioxane (ODAP-POSS) has been synthesized. This U-PY/ODAP-POSS contains eight pyrene chromophore arms formed through complementary uracil-diamidopyridine (U-DAP) pairs and exhibits high quantum efficiencies and good solution processing properties. The photoluminescence spectra of U-PY/ODAP-POSS (50/50) reveal that the color is stable after heating the sample at 150 °C for 1 h, in contrast, the pyrene/ODAP-POSS (50/50) shows significant thermal quenching. An electroluminescence (EL) device based on U-PY/ODAP-POSS exhibits higher maximum brightness and higher luminance efficiency relative to that of the U-PY. In addition, U-PY/ODAP-POSS also behaves as an effective dopant that enhances energy transfer from itself to MEH-PPV. The U-PY/ODAP-POSS-doped MEH-PPV blends exhibit high luminance efficiency, 1.45 times greater than MEH-PPV.

Self-supporting Polymer from a POSS Derivative

A new polyhedral oligomeric silsesquioxane macromer, octakis[N-(6-aminopyridin-2-yl)undecanamide-10-dimethyl-siloxy]silsesquioxane (POSS-C11-Py), containing eight diaminopyridine arms, is able to self-assemble to form a physically crosslinked polymer-like structure with good mechanical properties (tensile strength = 46.1 MPa, tensile modulus = 0.58 GPa, elongation = 49.3%) through quadruple hydrogen bonding interactions between these arms. POSS-C11-Py is the first organic/inorganic supermolecule possessing polymer-like mechanical properties as a result of self-complementary interactions, providing a potential route toward the design and fabrication of polymer-like supramolecular materials.

Bioinspired hole-conducting polymers for application in organic light-emitting diodes

A novel uracil-functionalized poly(3-thiophene) as a hole-injecting/transporting layer in an organic light-emitting device is able to form physical crosslinkages resulting in high thermal stability, non-corrosion, excellent hole injection/transport and electron-blocking capabilities in the solid state, and it achieves up to 10 times higher performance than that of conventional poly(3-thiophene)s under similar experimental conditions.

A new supramolecular film formed from a silsesquioxane derivative for application in proton exchange membranes

A new polyhedral oligomeric silsesquioxane ionomer (HCl-doped POSS-C11-Py) has been investigated. This new ionomer is able to self-assemble through macromers by quadruple hydrogen bonding interactions into a physically crosslinked polymer-like material that can be easily fabricated into films with micro-phase separation. This HCl-doped POSS-C11-Py membrane exhibits higher proton conductivity than a typical Nafion® membrane at high temperature, which is extremely rare for a non-sulfonic acid system. This newly developed material may provide an alternative route toward design and fabrication of a new type of proton exchange membranes.

A new benzoxazine containing uracil, complementary functionality

A new benzoxazine, uracil containing benzoxazine (UBz), has been successfully synthesized. The FTIR and DSC measurement of the poly(UBz)/poly(BA-a) blends indicated that hydrogen bonding interactions between uracil groups would result in a decrease in the exothermic peak temperature. In addition, the PL measurement confirmed that the poly(UBz)/poly(BA-a) blend possessed complementary behavior.

Hierarchical structures formed from self-complementary sextuple hydrogen-bonding arrays

A new self-complementary supramolecule based on U-DPy possesses an extremely high association constant, far exceeding those of existing systems (Kdimer > 107 M−1). In addition, its sextuple hydrogen bonding interaction and π-packing can be further promoted through annealing, resulting in a flat ribbon structure.

New self-assembled supramolecular polymers formed by self-complementary sextuple hydrogen bond motifs

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 (Ka >107 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.

Block-copolymer-like supramolecules confined in nanolamellae

This paper describes the development of a new concept in supramolecular assembly of existing functional polypeptides to form diblock-like molecular clusters through complementary hydrogen-bonding interactions, providing a potential route toward design and fabrication of block copolymer-like supramolecular materials.