Влияние полимерных добавок на процесс электроформования и структуру нановолокнистых материалов

The effect of addition of polymeric blends to spinning solution on fiber diameter and on structure of the electrospun nanofibrous materials is investigated.В работе рассмотрено влияние полимерных добавок в прядильные растворы, оказываемое на диаметр волокон и структуру нановолокнистых материалов, получаемых методом электроформования

ИССЛЕДОВАНИЕ ПРОЦЕССА ЭЛЕКТРОФОРМОВАНИЯ СОПОЛИМЕРНОГО ПОЛИАМИДА-6/66 В СПИРТОВОДНОЙ СМЕСИ

In this work the electrospinning of copolymeric polyamide-6/66 in ethanol-water solution is studied and the properties of the obtained fibrous materials are investigated. The principal possibility of obtaining fibrous materials in ethanol-water spinning solutions via electrospinning is shown. The optimal ratio of these solvents in spinning solution is determined. The investigated properties of the obtained fibrous materials include fiber diameters, fiber size distribution and packing density.В работе исследован процесс электроформования спиртоводных растворов сополимерного полиамида-6/66 и изучена структура получаемых волокнистых материалов

Electronic structure and magnetic properties of the spin-1/2 Heisenberg system CuSe2O5

A microscopic magnetic model for the spin-1/2 Heisenberg chain compound CuSe2O5 is developed based on the results of a joint experimental and theoretical study. Magnetic susceptibility and specific heat data give evidence for quasi-1D magnetism with leading antiferromagnetic (AFM) couplings and an AFM ordering temperature of 17 K. For microscopic insight, full-potential DFT calculations within the local density approximation (LDA) were performed. Using the resulting band structure, a consistent set of transfer integrals for an effective one-band tight-binding model was obtained. Electronic correlations were treated on a mean-field level starting from LDA (LSDA+U method) and on a model level (Hubbard model). In excellent agreement of experiment and theory, we find that only two couplings in CuSe2O5 are relevant: the nearest-neighbour intra-chain interaction of 165 K and a non-frustrated inter-chain coupling of 20 K. From a comparison with structurally related systems (Sr2Cu(PO4)2, Bi2CuO4), general implications for a magnetic ordering in presence of inter-chain frustration are made.Comment: 20 pages, 8 figures, 3 table