Search results for " NANO"

Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence

2019

Demonstration of similar microstructure is essential for demonstrating the equivalence of generic topical products since the microstructure of semisolids may affect the drug release. The objective of this study was to compare the microstructure-defining physical parameters of different batches of a reference ointment containing calcipotriol and betamethasone (Daivobet 50 &micro

Predicting stiffness and strength of birch pulp:Polylactic acid composites

2016

This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…

Investigation on the stability of dispersion of zirconia nanoparticles prepared by microwave- hydrothermal synthesis

2005

Difficulties in reproducing the performances of nanoparticles dispersions are obstructive for the progress of the nanotechnology. A plausible reason for this variability is the lack of the control of the stability as well as the dimensions of the nanoparticles in the dispersions. In this work we report results of investigations on the stability of zirconia nanoparticles in aqueous medium, monitoring nanoparticles sizes by means of Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS). Nanocrystalline zirconia powders, prepared by microwave-hydrothermal synthesis, were determined to be 6-8 nm in size by TEM observations. By using DLS technique the as-prepared dispersions wit…

Fractal-like Hierarchical CuO Nano/Microstructures for Large-Surface-to-Volume-Ratio Dip Catalysts

2022

Dip catalysts are attracting interest in both academia and industry for catalyzing important chemical reactions. These provide excellent stability, better recoverability, recyclability, and easy scale-up. Using the unique microstructures of leaf skeletons, we present a fractal-like hierarchical surface that can be used as a versatile and efficient dip catalyst. Copper oxide microcactuses with nanoscalar features were fabricated onto the Bauhinia racemosa leaf skeletons via a combination of physical vapor deposition, electroplating, and chemical oxidation methods. The coated leaf skeletons have a very high surface area, and the three-dimensional (3D) morphology allows the reactants to encoun…

Properties-morphology-processing relationships in polymer based clay nanocomposites

2009

Polymorphism and Metallic Behavior in BEDT-TTF Radical Salts with Polycyano Anions

2012

Up to five different crystalline radical salts have been prepared with the organic donor BEDT-TTF and three different polynitrile anions. With the polynitrile dianion tcpd2− (=C[C(CN)2]32−), two closely related radical salts: α'-(ET)4tcpd·THF (1) (THF = tetrahydrofurane) and α'-(ET)4tcpd·H2O (2) have been prepared, depending on the solvent used in the synthesis. With the mono-anion tcnoetOH− (=[(NC)2CC(OCH2CH2OH)C(CN)2]−) two polymorphs with similar physical properties but different crystal packings have been synthesized: θ-(ET)2(tcnoetOH) (3) and β''-(ET)2(tcnoetOH) (4). Finally, with the mono-anion tcnoprOH− (=[(NC)2CC(OCH2CH2CH2OH)C(CN)2]−) we have prepared a metallic…

Monitoring Biological Damage on Paper-based Documents in the Historical Archive of the Palermo Astronomical Observatory

2017

Libraries and archives house a wide variety of documents made of materials of vegetal and animal origin: unbound papers and books, manuscripts and printed books, photographs (negative and positive), prints, maps, available to the public for reading needs, study and information. These materials are often subject to fluctuations in environmental and micro-environmental parameters. For this reason, it is essential to implement constant monitoring and control of environmental conditions and potential deteriogens in order to slow down deterioration processes. The monitoring of the microbial degradation of paper documents in the Historical Archives of Palermo Astronomical Observatory has revealed…

A magnetic look into the protecting layer of Au25 clusters

2016

The field of molecular metal clusters protected by organothiolates is experiencing a very rapid growth. So far, however, a clear understanding of the fine interactions between the cluster core and the capping monolayer has remained elusive, despite the importance of the latter in interfacing the former to the surrounding medium. Here, we describe a very sensitive methodology that enables comprehensive assessment of these interactions. Pulse electron nuclear double resonance (ENDOR) was employed to study the interaction of the unpaired electron with the protons of the alkanethiolate ligands in four structurally related paramagnetic Au25(SR)0 18 clusters (R ¼ ethyl, propyl, butyl, 2-methylpro…

Enhancing Light Emission in Interface Engineered Spin-OLEDs through Spin-Polarized Injection at High Voltages

2019

The quest for a spin-polarized organic light-emitting diode (spin-OLED) is a common goal in the emerging fields of molecular electronics and spintronics. In this device, two ferromagnetic (FM) electrodes are used to enhance the electroluminescence intensity of the OLED through a magnetic control of the spin polarization of the injected carriers. The major difficulty is that the driving voltage of an OLED device exceeds a few volts, while spin injection in organic materials is only efficient at low voltages. The fabrication of a spin-OLED that uses a conjugated polymer as bipolar spin collector layer and ferromagnetic electrodes is reported here. Through a careful engineering of the organic/…

Pārejas metālu halkogenīdu 1D un 2D nanostruktūru sintēze un raksturošana

2016

Darbā tiek aplūkotas divdimensiju (2D) pārejas metālu halkogenīdu - volframa un molibdēna disulfīdu - īpašības un iegūšanas metodes. Ir demonstrēta šo 2D mikrokristālu sintēzes metode no gāzveida reaģentiem, kā arī izstrādātas jaunas metodes viendimensiju (1D) metālu oksīdu nanovadu core-shell heterostruktūru izgatavošanai, veidojot plānus disulfīdu pārklājumus uz ZnO nanovadiem, izmantojot ar reaktīvo magnetrona izputināšanu iegūtu pārklājuma sulfurēšanu vai attiecīgo pārejas metālu amonija sāļu pārklājuma termolīzi gāzveida sēra klātbūtnē. Iegūtās nanostruktūras tika izgatavotas un raksturotas, izmantojot LU CFI pieejamās zinātniskās iekārtas. Darbs sastāv no literatūras apskata un eksper…