Stabilizing Capability of Gum arabic on the Synthesis of Poly(Styrene-Methylmethacrylate-Acrylic Acid) Latex for the Generation of Colloidal Crystal Films

This article describes the generation and characterization of colloidal crystals from particles of gum arabic (GA) and sodium dodecylbenzene sulfate (SDBS) emulsified poly(styrene methylmethacrylate-acrylic acid) (P(St-MMA-AA) latex. The colloidal latex was synthesized using GA and SDBS as the emulsifying agents and then used to generate colloidal crystal films via the vertical deposition technique. Dynamic light scattering analysis placed the average particle diameter, polydispersity and Zeta potential at about 122 nm, 0.014 and –36.20 mV for the as-synthesized GA emulsified terpolymer latex and 213 nm, 0.006, –35.60 mV for the SDBS emulsified terpolymer latex, respectively. Thermo-gravimetric analysis and differential scanning calorimetry showed comparable thermal stability for both prepared terpolymer samples. Microscopic analysis showed that the latex particles possess a core-shell morphology which readily assembles into a well ordered hexagonal arrangement of spherical particles with manifold layers. This study, therefore, shows comparable properties of terpolymer prepared using gum arabic as emulsifier with terpolymer synthesized using SDBS which is a conventional emulsifier. Keywords: Gum Arabic; sodium dodecylbenzene sulphate; colloidal crystal films; morphology; emulsifie

Effect of Digestate from Rubber Processing Effluent on Soil Properties

Anaerobic digestion of rubber processing effluent (RPE) was conducted at 1:1 Effluent to Inoculums ratio to obtain biogas at a 40–day retention time. The physicochemical properties of the RPE were determined before and after anaerobic digestion. Digestate obtained thereof was used as soil amendment to investigate its bio-fertility potential. To study the effects, three kilograms (3Kg) of soil samples were separately treated with 0, 200, 400, 600 of the digested RPE. The effluent applied were thoroughly mixed with the soil, watered regularly and left for eight weeks for adequate mineralisation and equilibration. The soil physicochemical properties were determined before and after the amendment. The results from the amended soils showed that application of the digestate enhanced soil quality (as soil organic carbon, N, P, K, Ca, Na and % base saturation were significantly higher than in the control). However, the soil pH remained in the acidic region and the soil exchangeable acidity reduced. Keywords: Digestate, soil properties, biogas, RPE