Materials Literature
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To explore the potential of the coordination chemistry of Pd and Pt halides with phosphinoacetylene ligands for the generation of novel, highly metallated organometallic coordination polymers, investigations on model compounds [MX2(PPh2 C identical to CPh)2] that exhibit trans-configured Pd centers and cis-configured…
A new triacid scaffold is described based on the cone-shaped cyclotriveratrylene (CTV) molecule that facilitates the triple helical folding of peptides containing either a unique blood platelet binding collagen sequence or collagen peptides composed of Pro-Hyp-Gly repeats. The latter were synthesized by segment conden…
High Curie temperature and high Q m piezoelectric materials were developed in (0.9- x )BiScO 3 – x PbTiO 3 –0.1Pb(Mn 1/3 Nb 2/3 )O 3 (BS–PT–PMnN). A morphotrophic phase boundary (MPB), separating the rhombohedral and tetragonal phase was found at x ∼0.6, where highest piezoelectric constant ( d 33 ) and electromechani…
In order to investigate the relevance of the equilibrium crystal shape of a nickel particle during carbon nanotube growth, we have performed self-consistent pseudopotential density-functional calculations. The nickel particle's equilibrium shape is obtained from the Wulff construction using the calculated surface ener…
A polycrystal plasticity model, embedded in a finite element framework, is used to describe the Portevin–Le Chatelier effect in a velocity controlled tension test. The transition from continuous to discontinuous band propagation is captured as the applied strain rate is decreased. Statistical analysis of the stress dr…
A small library of dendrimers based on triazines was prepared by varying the surface and interior linking groups to study the relationship between structure and the ability of some of these dendrimers to gel in acidified organic solvents including chloroform, methylene chloride, and benzene. Convergent, divergent, and…
Gallium-doped zinc oxide (GZO) films were deposited at RT by dc planar magnetron sputtering under various total gas pressures ( P tot ) ranging from 0.25 Pa to 2.5 Pa using Ar as the sputtering gas and a GZO ceramic oxide target. The GZO films showed highest crystallinity at P tot = 2.0 Pa and showed clear degradation…
The adsorption behavior of 4-cyanobiphenyl (CNBP) has been investigated by means of surface-enhanced Raman scattering (SERS). CNBP appeared to assume a tilted orientation on silver and gold. The presence of the ring C−H band denoted a rather vertical orientation of the biphenyl ring on Ag and Au. On the other hand, co…
The photodissociation of Cr(CO) 6 has been studied using direct dynamics including trajectory surface hopping. The dissociation takes place on a steep excited-state potential surface leading to ejection of a CO ligand within 100 fs in reasonable agreement with time-resolved studies by Fuβ et al. 1-3 Our dynamics studi…
The surface structure of monolayer graphite (MG) on a Ni(111) surface has been investigated using Li + -impact collision ion scattering spectroscopy (ICISS) and reflection high-energy electron diffraction (RHEED). The RHEED pattern showed a 1 ×1 structure for MG formed on the Ni(111) surface, and the ICISS measurement…
The properties of the softening “glass to rubber” dispersion of two archetypal amorphous polymers, polystyrene and polyisobutylene, appear to differ greatly. Previously, these differences have been explained by the larger intermolecular coupling between the repeat units in executing the local segmental motions in poly…
Novel R3TTF-sigma-A compounds 14, 16 and 19 (R3TTF = trial-kyletrathiafulvalene, sigma = saturated spacer, A = polynitrofluoren-9-dicyano-methylene acceptor) incorporating very strong donor and acceptor moieties have been synthesized by condensation of the corresponding R3TTF-sigma-fluoren-9-one diads with malononitri…
Poly(vinyl alcohol), PVA, is amenable to several structural modifications because of the presence of the hydroxyl moiety in the backbone. The chemical versatility of this polymer can be used for the obtainment of new wall-to-wall pH-responsive PVA chemical hydrogels and for the preparation of air-filled microspheres,…
An X-ray diffractometer connected with a molecular-beam epitaxy (MBE) system has been constructed for in situ studies on the growing surfaces of III–V compound semiconductors. This diffractometer is based on the (4+2) type, which has four axes for orienting the sample and two axes for positioning the detector. In addi…
In cubic PbZrO 3 , which undergoes an antiferroelectric phase transition, the distinct disorder of Pb at twelve sites toward the neighboring O is detected for the first time by analyzing high-energy X-ray powder diffraction data. In the charge density distributions, the covalent nature of the Pb–O bond is also reveale…
The triple-helix is a unique secondary structural motif found primarily within the collagens. In collagen, it is a homo- or hetero-tripeptide with a repeating primary sequence of (Gly-X-Y)(n), displaying characteristic peptide backbone dihedral angles. Studies of bulk collagen fibrils indicate that the triple-helix mu…
Block copolymers are known to generate nanoscale microdomains by microphase separation, if they are annealed at a temperature lower than their order-disorder transition temperatures. We attempted to transfer the microdomains onto substrates by only using the reactive-ion etching (RIE) method, which is widely used in s…
Experiments show that the impurities can drastically change grain boundary mobilities in a non-trivial manner. The most widely used type of theoretical model for impurity effects on boundary migration is a one-dimensional, continuum model, based upon several simplifying assumptions. Although several of these assumptio…
In situ Raman spectroscopy was used to determine the rate of polymorph turnover for MK-A, a multipolymorphic compound in development at Merck Research Laboratories. The known crystal forms of MK-A include four anhydrous polymorphs, two hydrates, and numerous solvates. The penultimate and pure steps of this process inv…
Four new isophorone and combined isophorone and thiophene bridged chromophores have been synthesized. All of these new high μβ chromophores possess our newly synthesized tricyanovinyldihydrofuran acceptors. Because of our unique acceptor design, all of our chromophores show high solubility in all organic solvents due…