Nanostructured liquid crystalline particles as an alternative delivery vehicle for plant agrochemicals

Agrochemical spray formulations applied to plants are often mixed with surfactants that facilitate delivery of the active ingredient. However, surfactants cause phytotoxicity and off-target effects in the environment. We propose the use of nanostructured liquid crystalline particles (NLCP) as an alternative to surfactant-based agrochemical delivery. For this, we have compared the application of commercial surfactants, di (2-ethylhexyl) sulfosuccinate and alkyl dimethyl betaine, with NLCP made from phytantriol, at concentrations of 0.1%, 1% and 5% on the adaxial surface of leaves of four plant species Ttriticum aestivum (wheat), Zea mays (maize), Lupinus angustifolius (lupin), and Arabidopsis thaliana. In comparison with the application of surfactants there was less phytotoxicity on leaves of each species following treatment with NLCP. Following treatment of leaves with NLCP analysis of cuticular wax micromorphology revealed less wax solubilization in the monocot species. The results clearly show that there are advantages in the use of NLCP rather than surfactants for agrochemical delivery.

On the low temperature strain aging of bainite in the TRIP steel

The aging behavior of a thermomechanically processed Mo-Al-Nb transformation-induced plasticity steel with ultrafine microstructure was investigated using transmission electron microscopy and atom probe tomography (APT). Strain aging at 73 K (200 °C) for 1800 seconds led to a significant bake-hardening response (up to 222 MPa). Moreover, aging for 1800 seconds at room temperature after 4 pct pre-strain also revealed a bake-hardening response (~60 MPa). The experimental results showed the formation of carbon Cottrell atmospheres around dislocations and the formation of carbon clusters/fine carbides in the bainitic ferrite during aging. It is proposed that this is associated with the high dislocation density of bainitic ferrite with formation of a complex dislocation substructure after pre-straining and its high average carbon content (~0.35 at. pct). The segregation of carbon and substitutional elements such as Mn and Mo to the retained austenite/bainitic ferrite interface during aging was observed by APT. This segregation is likely to be the preliminary stage for Mo-C particles’ formation. The aging after pre-straining also induced the decomposition of retained austenite with formation of ferrite and carbides.

Preparation of hemicyanine dye encapsulated silica particles and their application in cotton fabrics

Trans-4- [p- (N, N-Die (2-hydroxyethyl)) styryl] -N- ethyl pyridinium bromide (DHEASPBr-C2), a hemicyanine fluorescent dye, was encapsulated into silica nanoparticles by co-hydrolysis and co-condensation of organosilanes in the presence of the dye. The dye containing silica nanoparticles were applied onto cotton fabrics. Scanning electron microscopy (SEM), UV–vis spectra, single-photon emission fluorescence spectra and reflectance spectra of the samples were characterized. The SEM results showed that the particle size (ranging from 100-200 nm) and dye encapsulating (1.5-8.1 mg dye per g silica matrix) could be adjusted by the concentration of fluorescent dye and organosilanes. The reflectance of the treated cotton fabrics showed that there were obvious adsorption spectra in 410 - 540 nm and emission spectra in 560 - 700 nm.

Improving thermal conductivity of cotton fabrics using composite coatings containing graphene, multiwall carbon nanotube or boron nitride fine particles

Graphene, multi-wall carbon nanotube (MWCNT) and fine boron nitride (BN) particles were separately applied with a resin onto a cotton fabric, and the effect of the thin composite coatings on the thermal conductive property, air permeability, wettability and color appearance of the cotton fabric was examined. The existence of the fillers within the coating layer increased the thermal conductivity of the coated cotton fabric. At the same coating content, the increase in fabric thermal conductivity was in the order of graphene > BN > MWCNT, ranging from 132 % to 842 % (based on pure cotton fabric). The coating led to 73 %, 69 % and 64 % reduction in air permeability when it respectively contained 50.0 wt% graphene, BN and MWCNTs. The graphene and MWCNT treated fabrics had a black appearance, but the coating had almost no influence on the fabric hydrophilicity. The BN coating made cotton fabric surface hydrophobic, with little change in fabric color.