Materials Literature
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Diblock copolymers of poly( N -isopropylacrylamide- co - N -(2-hydroxypropyl)methacrylamide lactate) (poly(NIPAAm- co -HPMAm-lactate)) as a thermosensitive block and poly(ethylene glycol) (PEG) as a hydrophilic block form polymeric micelles above the cloud point (CP) of the temperature-sensitive block. Destabilization…
The square-planar structure of a diamagnetic Cu(III) complex of tetrakis(pentafluorophenyl)-substituted N-confused porphyrin was elucidated by X-ray diffraction analysis. The facile interconversion between Cu(II) (1) and Cu(III) (2) complexes was achieved by chemical oxidation/reduction, and the Cu(III)/Cu(II) redox p…
The onset and kinetics of martensitic transformations are controlled by impurities trapped during the transformation. For the alpha to omega transformation in Ti, ab initio methods yield the changes in both the relative stability of and energy barrier between the phases. Using the recently discovered transformation pa…
A variety of porphyrin arrays connected by diverse linkers have been envisaged and prepared for the applications in molecular photonics and electronics. From a viewpoint of operational requirements, the porphyrin arrays should have the very regular pigment arrangements which allow a facile light energy or charge flow…
We demonstrate that highly crystalline, monodisperse maghemite (γ-Fe 2 O 3 ) nanoparticles, synthesized in organic solvents, can be effectively transferred into an aqueous medium using an ammonium salt and stabilized at neutral pH. The nanoparticles remain monodisperse, as characterized by TEM and XRD, as well as supe…
A small de novo designed peptide (MAX3) is described that exhibits complete thermoreversible self-assembly into a hydrogel network. Importantly, a prerequisite to hydrogelation is that the peptide must first fold into a conformation conducive to self-assembly. At ambient temperature, MAX3 is unfolded, resulting in a l…
The use of supercritical carbon dioxide as a processing solvent for the physical processing of polymeric materials is reviewed. Fundamental properties of CO 2 /polymer systems are discussed with an emphasis on available data and measurement techniques, the development of theory or models for a particular property, and…
Hybride auf Kieselgelbasis mit lamellaren oder hexagonalen Strukturen entstehen direkt aus neuartigen Alkylsiloxan-Oligomeren 1. Diese Selbstorganisations-Strategie öffnet einen Zugang zu geordnetem mikroporösem Kieselgel und mesostrukturierten kieselgelbasierten Hybridmaterialien (siehe Schema: 1. Hydrolyse und Polyk…
We have used a variety of microscopy and spectroscopy techniques to study the crystal interior of l -glutamic acid ( l -Glu) during a solvent-mediated polymorphic transformation process. Remarkably, we have found the encapsulation of the stable form of l -Glu within the metastable form. In particular, we have verified…
We report B-LYP/6-31G* and B3-LYP/6-31G* density functional theory calculations on a set of polycyclic hydrocarbons, ranging in size from C 19 H 22 to C 36 H 32 , combining aromatic (unsaturated) and aliphatic (saturated, sp 3 -hybridized carbon) ring systems. These locally aromatic polycyclic hydrocarbons (LAPHs), ge…
Complex permittivity measurements were performed on sorbitol, xylitol, and sorbitol-xylitol mixture in the supercooled liquid state in an extremely wide frequency range from 10 microHz to 500 MHz at temperatures near and above the glass transition temperature. We determined detailed behavior of the relaxation paramete…
We investigated the electronic structures of chemically modified carbon nanotube tips under electric fields using density functional calculations. Hydrogen, oxygen, and hydroxyl group-terminated nanotubes have been considered as field emitters or probe tips. In the case of the open-ended tubes, the field emission orig…
Continuum theory is used to demonstrate that the presence of flexoelectricity significantly alters the response to an applied voltage of a homogeneous nematic liquid crystal cell above the ac Fréedericksz threshold voltage. In such a system there is a fitting degeneracy: we obtain very good fits between theory and exp…
Water-soluble chitooligosaccharides have been reported to have specific biological activities. In this study, the chitosan samples with different degree of acetylation were used separately to prepare chitooligosaccharide (COS) and highly deacetylated chitooligosaccharide (HDCOS) through the nitrous acid depolymerizati…
The structural and electronic properties of ${\mathrm{BaTiO}}_{3}$ (001) slabs in paraelectric (PE) phase and ferroelectric (FE) phases with a [001] FE distortion are investigated by first-principles calculations to explore a possible scenario for the surface conduction recently observed in the FE phase. Both ${\mathr…
Dendritic polymer-modified porous silica particles prepared by a poly(amidoamine) (PAMAM) dendrimer synthesis reaction were characterized by elementary analysis (EA) and size exclusion chromatography (SEC). EA demonstrated the successful alternate growth of dendritic layers on the particles. The phased growth of polym…
Conducting polymers are important materials for several applications, among them, newly developed sensors that are based on changes in the conductivity of polyaniline (PANI). These sensors usually have pH limitations related to PANI characteristics (need for positive charge on the nitrogen atoms to get high conductivi…
In searching for new and efficient mechanisms for moving or propelling nano-sized objects across a flat surface, we discuss the idea of using the periodically switchable topography of a certain class of polymer substrates. In this paper, we exploit the peculiar properties of diblock-copolymer and mixed brushes that ca…
We present a 13 C labelling method for revealing the growth model of the carbon nanotubes and monitoring the detailed growth process of a multi-walled carbon nanotube (MWNT) array. 13 C ethylene and 12 C ethylene are fed into the chemical vapour deposition (CVD) reactor with pre-designed time sequences to growth MWNT…
By performing extensive angle-resolved photoemission measurements using tunable linearly polarized synchrotron radiation with photon energies from 15 to 31 eV on high quality cleaved samples we have succeeded in experimentally mapping the occupied electronic bands of GaSe(0001) along all key symmetry directions. The e…