排序方式: 共有31条查询结果,搜索用时 390 毫秒
1.
A new mesoporous silica structure with cubic Iad symmetry has been synthesized. The structure has very large unit cell dimensions, up to 250 A in the as-synthesized form and 222 A after calcination, and the surface area is around 700 m2/g. The syntheses were done according to well-established synthesis conditions with the triblock copolymers Pluronics P103 or P123, except for the addition of NaI to the synthesis mixture. Small-angle X-ray scattering revealed that the sample has Iad symmetry. According to electron micrographs, the structure is similar to that of MCM-48, and we thus propose that the structure lies on the gyroid minimal surface. 相似文献
2.
Ambrosi M Fratini E Alfredsson V Ninham BW Giorgi R Lo Nostro P Baglioni P 《Journal of the American Chemical Society》2006,128(22):7209-7214
A bolaform surfactant, 1,12-diascorbyl dodecanedioate (BOLA12), with ascorbic acid units as the polar headgroups was synthesized for the first time. Once dispersed in water above 0.5% w/w, BOLA12 forms hollow nanotubes as revealed by cryo-TEM experiments. These nanostructures transform into clear micellar solutions on heating. X-ray diffraction and SAXS experiments were performed both on the pure solid and on its aqueous dispersions. The critical aggregation concentration and the phase behavior were determined by conductivity and DSC experiments. The latter technique provided also the amount of strongly bound, solvating water molecules that surround the polar headgroups. BOLA12 shows the same reducing properties of ascorbic acid, as indicated by the antioxidant activity evaluated with the DPPH method. This feature was used for the reduction of Pd(II) ions on the surface of the nanoassemblies, which lead to the formation of large bundles homogeneously coated with palladium as observed in SEM micrographs. 相似文献
3.
Sharada L. N. Sunitha S. N. T. Sabha Maryam Viveka T. L. Aparna Y. Prasad M. 《Research on Chemical Intermediates》2020,46(7):3341-3360
Research on Chemical Intermediates - The present work focused on the assembly of 2-((2-(4-chlorophenylamino)phenylimino)methyl)-6-methoxyphenol as primary ligand (VBL) and bidentate nitrogen... 相似文献
4.
Viveka Alfredsson 《Current Opinion in Colloid & Interface Science》2005,10(5-6):269-273
Studies published between 2001 and 2005 that utilise cryogenic transmission electron microscopy as a tool for investigating solutions containing DNA with or without amphiphiles present are reviewed. DNA or oligonucleotides form complexes with amphiphilic molecules such as lipids, so-called lipoplexes, and the structures and morphologies are excellent objects to study by cryogenic transmission electron microscopy. Recent studies show that this technique is an effective tool for identification of a range of structures such as unilamellar or multilamellar vesicles or dispersed liquid crystalline phases. 相似文献
5.
6.
S. Viveka M. Prabhuswamy Dinesha N. K. Lokanath 《Molecular Crystals and Liquid Crystals》2014,593(1):261-270
The title compound, C30H25FN2O3, was prepared from the four-component one-pot condensation reaction and the product crystallized using dimethylformamide. The structure of the compound was established by elemental analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV-Visible, and single-crystal X-ray diffraction. The compound crystallizes in the triclinic crystal system with the space group Pī, with unit cell parameters a = 10.286(2) Å, b = 11.795(2) Å, c = 21.331(4) Å, α = 100.270(3)°, β = 90.093(3)°, γ = 90.062(3)°, and Z = 4. The crystal and molecular structure of the title molecule is stabilized by intra-molecular interactions of types C–H···N and C–H···O. 相似文献
7.
S. Viveka M. Prabhuswamy Dinesha N. K. Lokanath G. K. Nagaraja 《Molecular Crystals and Liquid Crystals》2014,588(1):83-94
The substituted triarylimidazole, C24H22N2O3, was prepared from the three-component one-pot condensation reaction and the product was crystallized by using dimethylformamide. The structure of the compound was confirmed by elemental analysis, FT-IR, thermogravimetric analysis (TGA), UV-Visible and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic crystal system in the space group P21/c with unit cell parameters a = 10.509(3) Å, b = 18.748(5) Å, c = 22.016(6) Å, β = 90.844(5)°, and Z = 8. The crystal structure of the compound was stabilized by the inter-molecular interactions of types N–H???N, C–H???O, and C–H???N, and intra-molecular interactions of the type C–H???O. The structure also involves C–H???π interactions. 相似文献
8.
Sandeep S. Laxmeshwar S. Viveka D. J. Madhu Kumar Dinesha R. F. Bhajanthri G. K. Nagaraja 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):639-647
In this work, cellulose was modified by using 2-(trifluromethyl)benzoylchloride by base catalyzed reaction. Modification of cellulose was confirmed by IR studies. The biodegradable composite films were developed by a film casting method using modified cellulose with poly(vinyl alcohol) and polypyrrolidone in different compositions. Film composites showed good biodegradability. Better barrier and mechanical properties showed by film composites as the percentage of modified cellulose increased. This indicates the importance of modified cellulose as a reinforcing agent. After analyzing these properties of film composites we came to the conclusion that, these biocomposites can be used for membrane and packaging applications. 相似文献
9.
M. Prabhuswamy S. Viveka M. Ramegowda K. J. Pampa G. K. Nagaraja 《Molecular Crystals and Liquid Crystals》2016,629(1):110-119
The substituted imidazole C28H21ClN2O2, was prepared via multicomponent reactions and the product crystallized using dimethylformamide. The structure of the compound was established by elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-visible, proton nuclear magnetic resonance spectroscopy, and single-crystal X-ray diffraction. The molecule is crystallized in the tetragonal crystal system with the space group P43212 and with unit cell parameters a = 12.246(4) Å, b = 12.246(4) Å, c = 31.781(2) Å, and Z = 8. The molecular and crystal structures of the title molecule are stabilized by the intramolecular interactions, O-H···N and C-H···N, and intermolecular interaction, C-H···O. 相似文献
10.