Materials Literature
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Two novel star molecules functionalized with 7-azaindolyl and 2,2'-dipyridylamino groups have been synthesized. Both molecules possess a sixfold rotation symmetry. Molecule L1 is based on the hexaphenylbenzene core with the formula of hexa[p-(7-azaindolyl)phenyl]benzene, while molecule L2 is based on the hexakis(biphe…
Samples of colloidal chitin and chitosans with deacetylation degrees (DD) of 50, 65, 75 and 95% (DD50, DD65, DD75 and DD95, respectively) were prepared from shrimp chitin. The hydrolytic activity of cellulase on these samples increased with the increasing DD of chitosan, with DD95 being the most easily hydrolyzed. Col…
The reactions of [MeAl(2-py)3Li.thf] (1) with FeCl2 or Cp2Mn in toluene-thf give simple access to the Group 13-transition metal heterometallic complexes [{MeAl(2-py)3}2M][M = Fe (2), Mn (3)]; complex has been shown to be a highly selective styrene epoxidation catalyst in air.
Abstract Bulk mineralogical and chemical properties of a weathering profile derived from serpentinite were studied using classical pedological methods (Munsell soil colors, particle-size distribution, density, cation exchange capacity, exchangeable bases, among others) and inductively coupled plasma-atomic emission sp…
The solubilities of 1,3-benzenedicarboxylic acid (isophthalic acid) in water, acetic acid, and acetic acid + water solutions with mass fractions of acetic acid on a solute-free basis of 0.2056, 0.4083, and 0.6082, respectively, were measured. The concentration of the solution was determined by a gravimetrical method.…
Pulsed field gradient NMR (PFG-NMR) spectroscopy is introduced to probe the distribution and dynamics of long dextran sugars (77 kDa) in heterogeneous solutions containing submicron hollow polymeric capsules. The capsules are made using the layer-by-layer (LBL) self-assembly method of strong polyelectrolytes onto sili…
Charge dependence of surface plasma resonance (SPR) was investigated on 2 nm octanethiol-protected Au nanoparticles. Remarkably, if assuming that each Au-thiol bond localizes one free electron, the observed variations in peak position of the SPR bands as a function of charge can be precisely calculated by simple Mie t…
Abstract DIFFaX simulations show that the 3 R 1 and 3 R 2 polytypes of hydrotalcites (HT) have distinctly different X-ray powder diffraction (XRPD) patterns. The HT samples obtained by coprecipitation as well as those subjected to a subsequent hydrothermal treatment exhibit non-uniform broadening of lines in their XRP…
The mobility of poly(methyl methacrylate) [PMMA] in a blend with 20 wt % poly(ethylene oxide) [PEO] is assessed using quasi-elastic neutron scattering (QENS) and compared to pure PMMA. The primary conclusion is that the change in dynamics of PMMA, upon blending with PEO, is solely a result of the shift in T g . Althou…
Copper(II) complexes (1-3) of a sterically constrained phenol-based tetradentate N(2)O(2) ligand 1,4-bis(2-hydroxy-3,5-dimethylbenzyl)piperazine (H(2)L) have been reported. The associated anions of the copper(II) ion precursors have profound influence on the stoichiometry of the products. Thus, with perchlorate ion, t…
Benzene emissions from a relevant proportion of today's gasoline-driven passenger cars and light-duty vehicles can increase by up to 2 orders of magnitude when driving at high engine load (e.g., on highways). Under such conditions, post-catalyst benzene levels exceeded those found pre-catalyst. As a consequence, forma…
The paper presents results of FE-calculations on shear localizations in quasi-brittle materials during both an uniaxial plane strain compression and uniaxial plane strain extension. An elasto-plastic model with a linear Drucker-Prager type criterion using isotropic hardening and softening and non-associated flow rule…
Mesostructured silica−titania mixed oxide monoliths, in which the nanocrystalline titania is well dispersed inside the silicate framework, have been synthesized by a liquid crystalline templating approach in combination with sol−gel processing. Control over the different hydrolysis and condensation rates of silicon an…
We report a novel approach that uses block copolymer micelles as a means to create large area arrays of iron-containing nanoclusters capable of catalyzing the growth of carbon nanotubes (CNTs). The amphiphilic block copolymer poly(styrene- block -acrylic acid) (PS- b -PAA) forms micelles in solution which are capable…
The free energy barriers and a mechanism of the oxidation of the amino acid methionine in water and in granulocyte colony-stimulating factor (G-CSF) are analyzed via combined quantum mechanical and molecular mechanical (QM/MM) methods, constrained molecular dynamics, and committor probability calculations. The compute…
Understanding and controlling precipitation reactions is a major challenge for industrial crystallization. Calcium carbonate is a widely studied system: more than 3000 papers have been devoted to the subject over the past 10 years. The first step of the precipitation of calcium carbonate, from relatively concentrated…
The bow-shaped molecule 1 bearing a self-complementary DAAD-ADDA (D=donor A=acceptor) hydrogen-bonding array generates, in hydrocarbon solvents, highly ordered supramolecular sheet aggregates that subsequently give rise to gels by formation of an entangled network. The process of hierarchical self-assembly of compound…
The development of new methods for fabricating thin films that provide precise control of the three-dimensional topography and cell adhesion could lead to significant advances in the fields of tissue engineering and biosensors. This Communication describes the successful attachment and spreading of primary hepatocytes…
A photochromic polymer film containing three different diarylethene derivatives, that is, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (3) was prepared. Upon UV irradiation, the three de…
This paper describes the use of atomic force microscopy to directly image surface-attached 3-5 nm diameter gold nanoparticle seeds before and after seed-mediated growth into gold nanorods (Au NRs) and other shapes (spheres, triangles, and hexagons). Results show that Au NRs form from seeds growing in either one or two…