Simple Non-aqueous Fabrication Route for Oleic Acid Capped Luminescent Cadmium Sulphide Quantum Dots at Relatively Low Temperature

In this communication, we report a simplistic non-aqueous fabrication route for oleic-acid capped luminescent cadmium sulphide quantum dots at low temperature. The resulting quantum dots, obtained without using any complicated reagents, are cubic in phase, monodispersed and have excellent optical properties. The simplicity of this fabrication route is also promising to develop other oleic acid-capped metal sulphide quantum dots at relatively low temperature.

Study of the Crosslinking of PVA with Glyoxal in LbL Nanocomposites

Crosslinking is a common practice to improve the barrier properties of polymers. In this study, Montmorillonite (MMT) was used with Polyvinyl alcohol (PVA) to deposit nanocomposite coatings which were crosslinked with glyoxal (Gly) by Layer by Layer (LbL) on a PET substrate. Two crosslinking conditions were studied, under mild condition and with an acidic environment. Mild condition was useful to identify the reversibility steps and the optimum crosslinking times while the acidic environment was essential to investigate the crosslinking mechanism, by determining the permeability for different crosslinking times. PVA and PVA-MMT coatings showed a strong correlation between the permeability coefficients for different crosslinking times and the FTIR results.

Room Temperature Synthesis of Aminocaproic Acid-Capped Lead Sulphide Nanoparticles

Aminocaproic acid (ACA) mixed methanolic lead acetate-thiourea (PbAc-TU) complex as precursor for fabrication of lead sulphide (PbS) nanoparticles (NPs) has been explained. The size, structure and morphology of as-prepared ACA-capped PbS NPs were systematically characterized by scanning electron microscopy (SEM), Transmission electron mi-croscopy (TEM), X-ray diffraction (XRD), Uv-vis spectroscopy and Brunauer-Emmett-Teller (BET) techniques. The obtained results show that the synthesized PbS NPs are nanocrystalline, size quantized and their agglomeration shows a mesoporous network of 8.7 nm in pore size. The binding nature of ACA molecules on PbS surface was studied by thermo gravimetric analysis (TGA), Fourier transform infrared (FTIR) and X-ray photoelectron (XPS) techniques. Results indicate that ACA acts as a soft template that restricts the growth of PbS NPs through its binding to Pb surface via nitrogen lone pair.

Fabrication of Microporous Membranes from Melt Extruded Polypropylene Precursor Films via Stretching: Effect of Annealing

In this work, the effects of annealing conditions on the microstructure of polypropylene（PP） precursor films and further on the porous structure and permeability of stretched membranes were investigated. Combinations of WAXD, FTIR, DSC and DMA results clearly showed the crystalline orientation and crystallinity of the precursor film increased with annealing temperature, while the molecular chain entanglements in the amorphous phase decreased. Changes in the deformation behavior suggested more lamellar separation occurred for the films annealed at higher temperatures. Surface morphologies of the membranes examined by SEM revealed more pore number and uniform porous structure as the annealing temperature increased. In accordance with the SEM results, the permeability of the membranes increased with annealing temperature. On the other hand, it was found that 10 min was almost enough for the annealing process to obtain the microporous membranes with an optimal permeability.