Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
We present a scaling theory to describe equilibrium conformations of weakly charged polyelectrolyte molecules grafted at one end onto impermeable surfaces of various morphologies (spheres, cylinders) and of arbitrary curvature. We focus on the case of sufficiently densely grafted chains, i.e., on curved polyelectrolyt…
A simple theoretical model describing the effects of pH and salt concentration on the permeability and counterion transport number of variable permeability membranes has been presented and validated experimentally for the case of poly(vinylidene fluoride) membranes graft modified with poly(acrylic acid) chains by radi…
The effect of adding ethylene-propylene copolymer (EPR) into polypropylene (PP), with particular emphasis on the impact fracture characteristics, will be presented in this work. The impact fracture characterization techniques used include the notched Izod impact strength, drop-weight dart impact, and the impact fractu…
Are non‐stick surfaces “the chemical analogue of the perpetual motion machine”, i.e., unattainable? Cheap and simple‐to‐produce systems with ultra‐low surface energy—and so on the way towards this ideal—are polyelectrolyte–surfactant complexes. Polarization micrographs of such systems involving fluorinated surfactants…
This paper sets down in detail the observation, first announced as a note (Romo-Uribe, A.; Windle, A. H. Macromolecules 1993, 26, 7100), of a strident and reversible orientation transition in a specially synthesized series of thermotropic random copolyester melts of the Vectra A900 type. The transition is between the…
The electrohydrodynamic pattern forming instability (EHC) driven by an ac voltage applied to a homeotropically aligned nematic liquid crystal layer is experimentally studied near onset. By controlling an external magnetic field, many different scenarios become accessible. For finite fields various regular convective s…
In this paper the deposition of very thin films of TiO 2 on different substrates (SiO 2, MgO, Ag) is studied by XPS. Shifts in the Ti 2p BE and the Auger parameter of Ti (α‘ = Ti 2p BE + Ti L 3 M 23 V Auger KE) are observed on the three substrates. The magnitude and the sign of the shifts with respect to those of bulk…
The phase behavior of poly(methyl methacrylate) (PMMA)/poly(4-vinylphenol) (PVPh) blends was investigated using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), small-angle X-ray scattering (SAXS), and Fourier transform infrared (FTIR) spectroscopy. Only one glass transition was obs…
Homoleptic copper(I) and silver(I) complexes [M(n)(L-L)(2)(n)()](BF(4))(n)() (M = Cu or Ag; L-L = MeECH(2)EMe; E = S, Se or Te) have been prepared and characterized by analysis, FAB mass spectrometry, and IR and multinuclear NMR spectroscopy ((1)H, (77)Se, (125)Te, (63)Cu and (109)Ag). The single-crystal X-ray structu…
Ab initio DDCI2 (difference-dedicated configuration interaction) calculations are performed on the exchange coupling constant of the doubly-bridged Ni(II) complexes [Ni(en)(2)Cl](2)(2+) and [Ni(terpy)(N(3))](2)(2+), which are modeled by substituting the external ligands with ammonia groups. The variational CI space is…
The effect of copolymer architecture on the phase behavior of a ternary polymer blend containing two homopolymers and a copolymer as well as the interfacial characteristics of this blend in the phase-separated state are examined using Monte Carlo simulation. At low copolymer concentration ( ca . 1%), the phase transit…
The previously unknown heteropolyoxometalates [gamma-SiO(4)W(10)O(32)(OH)Cr(2)(OOCR)(2)(OH(2))(2)](5-) (R = H, CH(3)) have been prepared by the reaction of [gamma-SiO(4)W(10)O(32)](8-) with [Cr(OH(2))(6)](3+) in formate or acetate buffer solution. Isolation of these new Cr(III)-substituted polyoxometalates was accompl…
The effect of ionic aluminate and silicate species on the structure of surfactant aggregates used in the preparation of mesoporous aluminosilicates was investigated using dynamic light scattering and rheological techniques. Aqueous cetyltrimethylammonium chloride (CTAC) solutions saturated with sodium aluminate, sodiu…
This paper is devoted to two new aromatic polyamines derived from p -EFTP (5‘-(4-(bis(4-ethylphenyl)amino)phenyl)- N, N, N ‘, N ‘-tetrakis(4-ethylphenyl)-1,1‘:3‘,1‘‘-terphenyl-4,4‘‘-diamine) and exhibiting meta connections around a central phenylene ring. In p -EFDP (5‘-phenyl-( N, N, N ‘, N ‘-tetrakis(4-ethylphenyl)-…
We have employed extensive configurational searches for numerical characterization of neutral (SiO 2 ) n clusters in their mechanically stable forms, i . e ., at local potential energy minima. These calculations have used additive pair interactions derived by Tsuneyuki et al ., supplemented with small-distance configu…
Abstract
The application of neutron diffraction techniques to aqueous solutions is described, and a framework involving the use of isotopic substitution is set up to illustrate the scope of the method. Specific applications described include a study of glassy electrolytes and aqueous solutions under nonambient conditions.
Contents include : Introduction Negative staining: historical background and technical development Negative staining: preparative procedures Negative staining: some specialized approaches and problems Negative staining: selected applications Unstaine
In this work, the novel reaction mechanism initiated by the fast CH( 2 Π) + C 2 H 2 → C 3 H 2 + H reaction (r13a) and followed by C 3 H 2 + O → C 2 H + HCO (or H + CO) (r25a) was established as the dominant C 2 H formation pathway in low-pressure acetylene/atomic oxygen flames at 600 K. The C 2 H 2 /O/H flames were in…
The influence of substituents with increasing steric demands on the structure of nickel(II) 5,15-disubstituted porphyrins has been investigated with X-ray crystallography, UV−visible absorption spectroscopy, resonance Raman spectroscopy, molecular energy optimization calculations, and INDO/s molecular orbital calculat…