Organic-skinned inorganic nanoparticles: surface-confined polymerization of 6-(3-thienyl)hexanoic acid bound to nanocrystalline TiO2

There are many practical difficulties in direct adsorption of polymers onto nanocrystalline inorganic oxide surface such as Al2O3 and TiO2 mainly due to the insolubility of polymers in solvents or polymer agglomeration during adsorption process. As an alternative approach to the direct polymer adsorption, we propose surface-bound polymerization of pre-adsorbed monomers. 6-(3-Thienyl)hexanoic acid (THA) was used as a monomer for poly[3-(5-carboxypentyl)thiophene-2,5-diyl] (PTHA). PTHA-coated nanocrystalline TiO2/FTO glass electrodes were prepared by immersing THA-adsorbed electrodes in FeCl3 oxidant solution. Characterization by ultraviolet/visible/infrared spectroscopy and thermal analysis showed that the monolayer of regiorandom-structured PTHA was successfully formed from intermolecular bonding between neighbored THA surface-bound to TiO2. The anchoring functional groups (-COOH) of the surface-crawling PTHA were completely utilized for strong bonding to the surface of TiO2

LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 ?? 2H2O) by Hydrothermal Method

Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Liion batteries. Many of the reported works on LiFePO4, synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4, shows promise.The present study reports LiFePO4, nanostructures prepared from iron (III) phosphate (FePO4 center dot 2H(2)O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz, bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4, resulted at pH >= 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.close

Corrosion protection and control using nanomaterials /

"Corrosion is an expensive and potentially dangerous problem in many industries. The potential application of different nanostructured materials in corrosion protection, prevention and control is a subject of increasing interest. This book explores the potential use of nanotechnology in corrosion control and is divided into two parts. Part one looks at the fundamentals of corrosion behavior and the manufacture of nanocrystalline materials. Chapters discuss the impact of nanotechnology in reducing corrosion cost, and investigate the influence of various factors including thermodynamics, kinetics and grain size on corrosion behavior. Part two provides a series of case studies that review oxidation protection using nanocrystalline structures at various temperatures, sol- gel and self-healing nanocoatings and the use of nanoreservoirs and polymer nanocomposites in corrosion control."--Includes bibliographical references and index.PART 1 CORROSION BEHAVIOUR AND MANUFACTURE OF NANOCRYSTALLINE MATERIALS: The impact of nanotechnology in reducing corrosion cost; Corrosion and nanomaterials: thermodynamic and kinetic factors; Understanding the corrosion resistance of nanocrystalline materials: the influence of grain size; Understanding the corrosion resistance of nanocrystalline materials: electrochemical influences; Electrodeposition: the versatile technique for nanomaterials -- PART 2 THE USE OF NANOMATERIALS IN CORROSION CONTROL: Moderate temperature oxidation protection using nanocrystalline structures; High temperature oxidation protection using nanocrystalline coatings; Nanocoatings to improve the tribocorrosion performance of materials; Self-healing nanocoatings for corrosion control; The use of nanoreservoirs in corrosion protection coatings; Nanoparticle-based corrosion inhibitors and self-assembled monolayers; Sol-gel nanocoatings for corrosion protection; Polymer nanocomposites in corrosion control; Nanocoatings for corrosion protection of aerospace alloys; Nanoscience and biomaterial corrosion control."Corrosion is an expensive and potentially dangerous problem in many industries. The potential application of different nanostructured materials in corrosion protection, prevention and control is a subject of increasing interest. This book explores the potential use of nanotechnology in corrosion control and is divided into two parts. Part one looks at the fundamentals of corrosion behavior and the manufacture of nanocrystalline materials. Chapters discuss the impact of nanotechnology in reducing corrosion cost, and investigate the influence of various factors including thermodynamics, kinetics and grain size on corrosion behavior. Part two provides a series of case studies that review oxidation protection using nanocrystalline structures at various temperatures, sol- gel and self-healing nanocoatings and the use of nanoreservoirs and polymer nanocomposites in corrosion control."--Print version record.Elsevie

Internal displacement reactions in multicomponent oxides: Part I. Line compounds with narrow homogeneity range

Structure and phase transition of LaO1−xF1+2x, prepared by solid-state reaction of La2O3 and LaF3, was investigated by X-ray powder diffraction and differential scanning calorimetry for both positive and negative values of the nonstoichiometric parameter x. The electrical conductivity was investigated as a function of temperature and oxygen partial pressure using AC impedance spectroscopy. Fluoride ion was identified as the migrating species in LaOF by coulometric titration and transport number determined by Tubandt technique and EMF measurements. Activation energy for conduction in LaOF was 58.5 (±0.8) kJ/mol. Conductivity increased with increasing fluorine concentration in the oxyfluoride phase, suggesting that interstitial fluoride ions are more mobile than vacancies. Although the values of ionic conductivity of cubic LaOF are lower, the oxygen partial pressure range for predominantly ionic conduction is larger than that for the commonly used stabilized-zirconia electrolytes. Thermodynamic analysis shows that the oxyfluoride is stable in atmospheres containing diatomic oxygen. However, the oxyfluoride phase can degrade with time at high temperatures in atmospheres containing water vapor, because of the higher stability of HF compared with H2O

One-dimensional (1D) nanostructured and nanocomposited LiFePO4: its perspective advantages for cathode materials of lithium ion batteries

Nanostructured materials have attracted recent research interest as battery materials due to their expected enhancement of properties. The characteristic nanoscale dimension and its structuring guarantees improved charge and mass transfer during charge/discharge processes. Among the potential cathode materials investigated as a substitute to LiCoO2, one of the most promising materials is LiFePO4 with olivine structure (LFP). In this perspective article, the current research and development in the synthesis and electrochemical studies of nanostructured LFP are reviewed with a special emphasis on one-dimensional (1D) nanostructures and nanocompositing with 1D conductive materials. In addition to various examples of 1D LFP with detailed synthetic methods, why 1D nanostructures could be meaningful is discussed in terms of a geometric point of view and the anisotropic lithiation/de-lithiation mechanism of LFP.close121

Localized drug delivery of selenium (Se) using nanoporous anodic aluminium oxide for bone implants

Electrochemically engineered nanoporous anodized aluminium oxide (AAO) prepared on aluminium (Al) foil by anodization process was employed as a platform for loading different forms of selenium (Se) in order to investigate their release behaviour and potential application for localized drug delivery targeting bone cancer. Several forms of Se including inorganic Se (HSeO), organic Se ((CH)Se), metallic Se, their chitosan composites, electrodeposited (ED) and chemical vapour deposited (CVD) Se were explored and combined with another model drug (indomethacin). Structural, drug-loading and in vitro drug-releasing characteristics of prepared Se-based drug delivery carriers were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and UV-visible spectroscopy (UV-Vis), respectively. Sustained and controlled release of Se was demonstrated through chitosan-composites of inorganic, organic or metallic forms of Se loaded into nanoporous AAO carriers. Cell viability studies showed decreasing toxicity to cancer cells in the order: inorganic Se > ED Se > CVD Se > metallic Se > organic Se. The study suggests new alternatives for localized drug treatment based on low-cost nano-engineered carriers loaded with Se having anti-cancer properties

Regulating the Anode Corrosion by a Tryptophan Derivative for Alkaline Al–Air Batteries

Screening a green corrosion inhibitor that can prevent Al anode corrosion and enhance the battery performance is highly significant for developing next-generation Al–air batteries. This work explores the non-toxic, environmentally safe, and nitrogen-rich amino acid derivative, N(α)-Boc-l-tryptophan (BCTO), as a green corrosion inhibitor for Al anodes. Our results confirm that BCTO has an excellent corrosion inhibition effect for the Al-5052 alloy in 4 M NaOH solution. An optimum inhibitor addition (2 mM) has increased the Al–air battery performance; the corrosion inhibition efficiency was 68.2%, and the anode utilization efficiency reached 92.0%. The capacity and energy density values increased from 990.10 mA h g–1 and 1317.23 W h kg–1 of the uninhibited system to 2739.70 mA h g–1 and 3723.53 W h kg–1 for the 2 mM BCTO added system. The adsorption behavior of BCTO on the Al-5052 surface was further explored by theoretical calculations. This work paves the way for constructing durable Al–air batteries through an electrolyte regulation strategy