Jilin Hu

Processing and properties of Cfibre/SiCfillers/SiOC composites using solvent free liquid polysiloxane as matrix source

Abstract Carbon fibre reinforced SiOC composites (denoted as Cfibre/SiCfillers/SiOC) were prepared by slurry coating and polymer infiltration pyrolysis (PIP) process. Low viscosity liquid polysiloxane (PSO) and SiC powder were combined at a 1∶1 weight ratio to produce a blend (S-PSO), which was employed as matrix source. Heat treated carbon fibre fabric was adopted as the reinforcement. The lamination process was determined on the basis of cure and rheology investigations on S-PSO. The effects of PIP cycles and temperature of heat treatment of the carbon fibre on the mechanical properties of Cfibre/SiCfillers/SiOC were examined. The results indicate that composites using carbon fibres annealed at 1700°C as reinforcement reached a maximum flexural strength of 300 MPa after six PIP cycles. The resistance of the Cfibre/SiCfillers/SiOC composite to oxidation was also evaluated. Without any protective coatings, the composite retained 60% of its strength after oxidation at 800°C for 3 h in a static air environment.

Fe3O4@ZnS@Glycine nanoparticle as a novel microwave stimulus controlled drug release system

The stimuli-responsive controlled drug delivery system is highly desirable for an efficient cancer treatment approach. Herein, we have successfully developed a novel multifunctional microwave stimulus controlled anticancer drug release system based on magnetic Fe3O4@ZnS@Glycine nanoparticles. Fe3O4 core has a high magnetization saturation value for drug targeting under foreign magnetic fields. ZnS shells can efficiently convert microwave energy into thermal energy for microwave-triggered drug release. The glycine-modified layer of nanoparticles provides active group (–NH2) for the loading of drug molecules by hydrogen bond. The in vitro studies have clearly demonstrated the feasibility and advantage of the novel nanocarriers for remote-controlled drug release systems.Graphical AbstractWe combined the advantages of ZnS nanoparticles with those of Fe3O4 and glycine to create a new drug delivery system, which is capable of carrying drug molecules and triggered release of the drug by microwave treatment.

Egg albumin-assisted sol–gel synthesis and photo-catalytic activity of SnO 2 micro/nano-structured biscuits

SnO2 micro/nano-structured biscuits had been successfully prepared via egg albumin-assisted sol–gel procedure. The typical sample calcined at 900 °C was pure SnO2 with a tetragonal rutile structure, constructed by the numerous pomegranate seed-like irregular nanoparticles in the range of ~100 to ~400 nm. The complexation of egg albumin and tin ions and the bonding characteristics of functional groups had been confirmed. The band gap energy values of samples were apparently higher than the reference value of bulk matter, which could be assigned to a well-known effect that small particles tended to exhibit increased band gaps. It was revealed that with the increase of the calcined temperature the photoluminescence efficiency increased. The sample at 500 °C had the higher photocatalytic activity and the higher mean photo-degradation rate of MO was 88.1 ± 1.2% as compared to other samples, which could be assigned to the lower value of band gap due to the defect levels in the band gap from the impurities formed during the growth and the lower photoluminescence efficiency, beneficial to electrons transfer and reducing the combination of electron and hole, which resulted in better photocatalytic activity.Graphical abstract

Thermal Stability and Spectral Properties of Tm 3+ -Yb 3+ CO-Doped Tellurite Glasses

Glasses of the system 75TeO2–20ZnO–5La2O3–0.8Tm2O3–xYb2O3 were prepared by high temperature melt cooling method. Results of differential scanning calorimetry indicate that, all glass samples have excellent thermal stability. Judd–Ofelt strength parameters, spontaneous emission probabilities, fluorescence branching rations, fluorescence radiative lifetime of Tm3+ ions in tellurite glass were calculated. The impact of Yb3+ concentration on the fluorescence properties of Tm3+ ions in the S band under the pumping wavelength of 465 nm was investigated in a suggestion that, 3H4 radiative lifetimes will be prolonged and the performance of optical amplifier gain of Tm3+ in tellurite glass co-doped with 0.5 mol % Yb3+ ions will be improved.

Synthesis of TiC–TiB2 composite powders via carbothermal reduction and its reaction mechanism

ABSTRACT Titanium carbide–titanium diboride (TiC–TiB2) composite powders were synthesised through a carbothermal reduction method by using titanium dioxide, boric acid, and different carbon sources (namely, carbon black, sucrose, and glucose) as starting materials. The thermal decomposition behaviour of the precursors was studied by thermogravimetry–differential thermal analyser. Phase compositions and morphologies of the synthesised products were characterised by X-ray diffractometer and scanning electron microscope. When n(Ti):n(B):n(C) = 1.0:2.5:5.0, the blended stock mainly formed TiB2 with sucrose or glucose as a carbon source, whereas the stock produced TiC when carbon black was the source. At an optimum reaction temperature, the particles of the powders synthesised from carbon black as a carbon source were the smallest at approximately 100 nm. With increasing amount of boric acid in the precursor, the morphologies of the samples changed into less spherical particles, and more flaky grains and small particles with irregular structures were observed.

A simple approach for the synthesis of bi-functional Fe3O4@MgO core–shell nanoparticles with magnetic-microwave to heat responsive properties

Core–shell structure nanomaterials have attracted considerable attention owing to their unique structure and promising applications in drug delivery and water treatment. A facile direct precipitation method has been developed for the synthesis of nanoparticles with bi functional magnetic to heat responsive properties with Fe3O4 nanoparticles as the core and MgO as the shell. Transmission electron microscopy (TEM) images revealed that the obtained bi-functional nanoparticles had a core–shell structure and a spherical morphology. The average size of the nanoparticle was ∼350 nm, and the thickness of the shell was ∼20 nm. The X-ray diffraction (XRD) patterns showed a cubic spinel structure of the Fe3O4 core and the MgO shell. The nanoparticles showed both strong magnetic and unique microwave to heat responsive properties, which may lead to development of nanoparticles with great potential for applications in drug targeting, controlled release, chemo- and microwave-thermal combination therapy and water treatment.