Search results for "solid-state chemistry"

2020

Worldwide, tons of lignin is produced annually in pulping plants and it is mainly considered as a waste material. Usually lignin is burned to produce energy for the pulping reactors. The production of value-added materials from renewable materials like lignin, has proved to be challenging. In this study, the effects of addition of three different types of lignin in the production of tannin/furanic foams is investigated. The foams were matured, first at 373 K and finally carbonized at 1073 K and the properties of them including mechanical strength, specific surface area and pore development are investigated before and after thermal treatment. According to the results, higher mechanical stren…

ChemInform Abstract: “Supramolecular” Solid-State Chemistry: Interpenetrating Diamond-Type Frameworks of U4+ Ions Linked by S,S′-Bidentate P2S2-6 Mol…

2010

Spintronics: a challenge for materials science and solid-state chemistry.

2007

Spintronics is a multidisciplinary field involving physics, chemistry, and engineering, and is a new research area for solid-state scientists. A variety of new materials must be found to satisfy different demands. The search for ferromagnetic semiconductors and stable half-metallic ferromagnets with Curie temperatures higher than room temperature remains a priority for solid-state chemistry. A general understanding of structure-property relationships is a necessary prerequisite for the design of new materials. In this Review, the most important developments in the field of spintronics are described from the point of view of materials science.

Modeling the acid-base properties of molybdate(VI) in different ionic media, ionic strengths and temperatures, by EDH, SIT and Pitzer equations

2017

This paper reports the results of a study on the determination of the protonation constants of MoO42 −, in NaClaq, NaNO3aq, KClaq, at different ionic strengths (0 < I/mol dm− 3 ≤ 5.0 in NaClaq, 0 < I/mol dm− 3 ≤ 3.0 in NaNO3aq and KClaq) and temperatures (278.15 ≤ T/K ≤ 318.15 in NaClaq, only 298.15 K in NaNO3aq and KClaq), by potentiometric (ISE-H+ glass electrode) and spectrophotometric (UV/Vis) titrations. After a critical analysis of results and literature findings, the proposed speciation model takes into account the formation of two monomeric and four heptameric species, namely: MoO4H−, MoO4H2, (MoO4)7H86 −, (MoO4)7H95 −, (MoO4)7H104 − and (MoO4)7H113 −. Due to the complexity of…

In vitro corrosion and biocompatibility of brushite/hydroxyapatite coatings obtained by galvanic deposition on 316LSS

2018

Corrosion behavior and cytotoxicity was reported for mixed brushite (BS)/hydroxyapatite (HA) coatings deposited on 316LSS substrate through a displacement reaction. Corrosion tests, carried out in a simulated body fluid, showed that in comparison with bare 316L, coating shifts Ecorrto anodic values and reduces icorreven if oscillations were observed, which were explained in terms of the chemical interactions at the solid/liquid interface. Cell biocompatibility of the coating was investigated through osteoblastic cell line MC3T3-E1, evidencing the absence of any cytotoxicity Taken together, the results show that galvanic deposition is a simple and cost-effective method for producing bioactiv…

“Supramolecular” Solid-State Chemistry: Interpenetrating Diamond-Type Frameworks of U4+ Ions Linked byS,S′-Bidentate P2S62− Molecular Rods in UP4S12

2001

Inseparably interwoven are three independent polymeric diamond-type U(P2 S6 )2 frameworks in the structure of the title compound. The linear P2 S6 units act as molecular rods linking the pseudotetrahedral U4+ centers. U(P2 S6 )2 may be viewed as a coordination polymer which is formed from U/P/S melts by the solid-state equivalent of the self-assembly reactions in solution.

Production and properties of doped PSN electro-optical ceramics

1997

Due to multifunctionality the transparent ferroelectric ceramics is attractive to solid state chemistry and physics as a promising material for active electro-optic elements. To study doping effects on the technological processing and properties, ceramic samples of Pb1-xZxSc1/2Nb1/2O3, have been prepared, where Z: (1) Ba (0 less than or equal to x less than or equal to 1), (2) rare-earth elements: Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu (x equals 0.1), (3) PbSc1/2Nb1/2O3 doped with 5 wt.% of rare-earth oxides. Ceramic characteristics, dielectric and electro-optical parameters have been measured. Differential thermal analysis (DTA), and x-ray diffraction are used to study the infl…

ortho -Fluorination of azophenols increases the mesophase stability of photoresponsive hydrogen-bonded liquid crystals

2018

Photoresponsive liquid crystals (LCs) whose alignment can be controlled with UV-Visible light are appealing for a range of photonic applications. From the perspective of exploring the interplay between the light response and the self-assembly of the molecular components, supramolecular liquid crystals are of particular interest. They allow elaborating the structure-property relationships that govern the optical performance of LC materials by subtle variation of the chemical structures of the building blocks. Herein we present a supramolecular system comprising azophenols and stilbazoles as hydrogen-bond donors and acceptors, respectively, and show that ortho-fluorination of the azophenol dr…

Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization

2014

Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100-200 nm thickness and with a pore diameter of 10nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that con…

Improvement of the photo-stability of polystyrene-block-polybutadiene-block-polystyrene through carbon nanotubes

2015

Abstract The photo-stability of Polystyrene-Polybutadiene-Polystyrene (SBS) based nanocomposites containing bare multi-walled carbon nanotubes (CNTs) and carbon nanotubes bearing carboxylic functional groups (CNTs-COOH) in comparison to that of pristine SBS has been studied. The photo-oxidation of pristine SBS occurs through crosslinking reactions and oxidized species formation and both these processes begin at early stage of exposure. The formation of crosslinking, formerly in polybutadiene phase, assessed by spectroscopical (FTIR), mechanical, dynamic mechanical and rheological analysis, leads to occurrence of internal mechanical stresses in the solid state and the SBS samples become prem…