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。
Poly( N -vinylcaprolactam) (PVCL) is a synthetic analogue of biomolecules (enzymes, proteins). It demonstrates a specific hydration and undergoes a coil–globule transition. The PVCL–D 2 O system (PVCL mass M = 10 6 ) has been investigated by small-angle neutron scattering (SANS) at T = 296–316 K to identify the struct…
[reaction: see text] The redox chemistry of pi-extended squaraines is investigated using cyclic voltammetry, in-situ spectroelectrochemistry and quantum chemical calculations. Squaraine 1 is reversibly oxidized to the radical cation and dication whereas reduction shows limited electrochemical but fully chemical revers…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSuspension Polymerization of l-Lactide in Supercritical Carbon Dioxide in the Presence of a Triblock Copolymer StabilizerDaniel Bratton, Malcolm Brown, and Steven M. HowdleView Author Information School of Chemistry, University of N…
A reconstruction method is presented for the generation of three-dimensional maps of the grain boundaries within powders or polycrystals. The grains are assumed to have a mosaic spread below 1°. They are mapped layer by layer in a non-destructive way by diffraction with hard X-rays. First the diffraction spots are sor…
[Tris(hexamethyldisilyl)amide] yttrium is a catalyst for the controlled ring-opening polymerization of ε-caprolactone when reacted with an excess of alcohol. Up to an alcohol-to-yttrium molar ratio of 50, the chain transfer to the alcohol is quantitative, and the molecular weight of the chains can be predicted from th…
We report a method to prepare hydrophilic poly(dimethylsiloxane) (PDMS) stamps that could transfer patterns of polar molecules homogeneously in soft lithography. In this method, we demonstrated a two-step procedure by using a mixed gas of argon (Ar) and hydrogen (H 2 )-based microwave plasma pretreatment to activate P…
The ground- and excited-state metal-ligand dynamics of nonplanar nickel(II) 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrin (NiDPP) and two fluorinated analogues (NiF(20)DPP and NiF(28)DPP) have been investigated using static and time-resolved absorption spectroscopy in toluene and in ligating media that differ i…
A series of photochemically active, “axial-bonding” type phosphorus(V) porphyrin−azoarene (P−A) conjugates, viz., [(TTP)P V ( - O-AZM) 2 ] +, [(TTP)P V ( - O-AZT) 2 ] +, [(TTP)P V ( - O-AZB) 2 ] +, and [(TTP)P V ( - O-AZN) 2 ] + ( TTP is 5,10,15,20-tetra(4-methylphenyl)porphyrinato dianion and O-AZM, O-AZT, O-AZB, and…
Electrodeposition is a low cost method for WO 3 thin film preparation. The starting dissolved tungsten precursor is a peroxo-compound which can be prepared by an equimolar mixing of sodium tungstate and hydrogen peroxide. The precursor preparation as well as the electrodeposition and precursor solution aging processes…
The effects of the choice of oxygen scattering curves with different ionization levels and of the number of spherical harmonics terms used to correct for preferred orientation are discussed in the case of the Rietveld refinement of MgAl 2 O 4 spinel. Results indicate that Rietveld refinements, and not only single-crys…
Polyelectrolyte-layered films containing α- and β-cyclodextrin were prepared by a layer-by-layer deposition of sulfonated α- or β-cyclodextrin (s-α-CyD or s-β-CyD) and cationic poly(allylamine hydrochloride) (PAH) on a solid surface. The deposition of the films from water solutions (no salt added) afforded thin films…
A polystyrene- block -poly(1,2-butadiene)- block -poly( tert -butyl methacrylate) (SBT) triblock copolymer and its analogues with different degrees of saponification, SB(T/A) with A being poly(methacrylic acid) are characterized in terms of their morphologies and infrared spectroscopic features. The chemical modificat…
Chitosan-dendrimer hybrids having various functional groups such as carboxyl, ester, and poly(ethylene glycol) groups were prepared successfully using dendrimer acetal by reductive N-alkylation. The synthetic procedure could be accomplished by one-step reaction without organic solvent. The degree of substitution of de…
Amorphous mesoporous AlPO 4 materials were prepared by a gel precipitation method using different phosphate precursors [H 3 PO 4, (NH 4 )H 2 PO 4, and (NH 4 ) 2 HPO 4 ], both in the presence and absence of an aluminum-complexing assisted gel agent (1,2-ethanediol, 1,2- and 1,3-propanediol, and 2-methyl-2,4-pentanediol…
The reaction of Ln(NO(3))(3).aq with K(3)[Fe(CN)(6)] or K(3)[Co(CN)(6)] and 2,2'-bipyridine in water led to five one-dimensional complexes: trans-[M(CN)(4)(mu-CN)(2)Ln(H(2)O)(4) (bpy)](n)().XnH(2)O.1.5nbpy (M = Fe(3+) or Co(3+); Ln = Sm(3+), Gd(3+), or Yb(3+); X = 4 or 5). The structures for [Fe(3)(+)-Sm(3+)] (1), [Fe…
The wide availability of X-ray area detectors provides an opportunity for using synchrotron radiation based X-ray diffraction for the determination of preferred crystallite orientation in polycrystalline materials. These measurements are very fast compared to other techniques. Texture is immediately recognized as inte…
A Michael reaction of chitosan was conducted in water containing acetic acid with various acryl reagents. The degree of substitution could be controlled by temperature, reaction time, and the amount of acryl reagents. Although the modified chitosan derivatives with acrylic acid esters showed water-solubility, that wit…
Four cubic compounds are reported that contain the supertetrahedral cluster [M(4)Sn(4)S(17)](10)(-) where M = Mn, Fe, Co, Zn. The cluster features a central quadruply bridging sulfide ion (mu(4)-S) that holds together four divalent M atoms in a tetrahedral arrangement. This core is capped with four tridentate [SnS(4)]…
The lattice parameters of α-Al 2 O 3 have been measured in a temperature range from 4.5 to 250 K with a relative accuracy of better than 6 × 10 −6 . The experimental method uses Bragg backscattering and the recently proposed Mössbauer wavelength standard, i.e. the wavelength λ M = 86.025474 (16) pm of the nuclear reso…
The frequency-dependent shear moduli were measured over a range of temperature for polyisoprene (PI, M = 22 000 and 78 000), poly(vinylethylene) (PVE, M = 10 000 and 120 000), and their blends. The longest relaxation times of each component in the blends were extracted by a modified Tsenoglou mixing rule, and converte…