New phase-pure nanohybrids of dichlorprop[2(2,4-dichlorophenoxy)propionate]-intercalated Zn/Al-LDH were successfully prepared using either co-precipitation or ion exchange methods. The basal spacing expansion from 8.9 Å in the layered double hydroxide (LDH) to 18.7 and 21.7 Å of the nanohybrids was observed. This together with FTIR, DTG/TGA and compositional studies show that dichlorprop was successfully intercalated into the Zn/Al-layered double hydroxides interlayer. Release study of dichlorprop showed that it is dependent on the concentration of the incoming ionic species and governed by the pseudo-second order kinetic. This study suggests that the layered double hydroxide might be used as a matrix for controlled release formulation for a herbicide, dichlorprop and the release of the herbicide can be tuned using parameters such as method of synthesis and the concentration of the incoming ionic species to be ion exchange with. This is towards new generation of agrochemicals which are safer as well as user- and environmentally-friendly.
Poly(lactic acid) (PLA)-based nanocomposites filled with graphene nanoplatelets (xGnP) that contains epoxidized palm oil (EPO) as plasticizer were prepared by melt blending method. PLA was first plasticized by EPO to improve its flexibility and thereby overcome its problem of brittleness. Then, xGnP was incoporated into plasticized PLA to enhance its mechanical properties. Plasticized and nanofilled PLA nanocomposites (PLA/EPO/xGnP) showed improvement in the elongation at break by 3322% and 61% compared to pristine PLA and PLA/EPO, respectively. The use of EPO and xGnP increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The nanocomposites also resulted in an increase of up to 26.5% in the tensile strength compared with PLA/EPO blend. XRD pattern showed the presence of peak around 26.5° in PLA/EPO/xGnP nanocomposites which corresponds to characteristic peak of graphene nanoplatelets. Plasticized PLA reinforced with xGnP showed that increasing the xGnP content triggers a substantial increase in thermal stability. Crystallinity of the nanocomposites as well as cold crystallization and melting temperature did not show any significant changes upon addition of xGnP. However, there was a significant decrease of glass transition temperature up to 0.3wt% of xGnP incorporation. The TEM micrograph of PLA/EPO/xGnP shows that the xGnP was uniformly dispersed in the PLA matrix and no obvious aggregation was observed.
ZnO/γ-Fe2O3 catalysts were fabricated via a simple precipitation route using zinc acetate and iron acetate as the precursors and ammonia as the precipitant. The resulted nanocatalysts were subjected to heat treatment at 450°C for 2 h. The characteristics of the nanocomposite were investigated by various characterization techniques. The synthesized nanocomposite has an average particle size of 13 nm and a surface area of 17 m2/g. The photocatalytic activity of ZnO/γ- Fe2O3 nanocomposite was evaluated by photodegrading 2,4-dichlorophenoxyacetic acid (2,4-D) under UV irradiation. The results showed that ZnO/γ-Fe2O3 nanocomposite exhibited enhanced photoactivity compared to pure ZnO with almost 20% increment within 4 h of reaction time. The result indicated the applicability of ZnO/γ-Fe2O3 nanocomposite to be used as photocatalyst in removing organic pollutants in wastewater.