Multi-walled carbon nanotubes (MWCNTs) have been known as an innovative carrier for drug support and delivery applications. Herein, the modification of MWCNTs was carried out to improve dispersibility and biocompatibility levels. MWCNTs were functionalized by an aqua regia of concentrated nitric acid (HNO3) and sulfuric acid (H2SO4) to produce functionalized MWCNTs (f-MWCNTs). Meanwhile, the salicylic acid was loaded on the f-MWCNTs by sonication technique and the resultant was coded as SA-MWCNTs. Dissolution analysis was carried out in the different medium of simulated body fluid (SBF), simulated gastric fluid (SIF) and simulated gastric fluid (SGF) to evaluate the profile of drug release of SA-MWCNTs. It was found that the release profile of aspirin displayed 2-stage of releases; (1) fast release within 1 to 5-hours followed by (2) sustainable release for up to 12-hours. Thus, showing the compatibility of the f-MWCNTs for salicylic acid controlled released system.
Demand for diesel continues to increase due to rapid population growth, which could contribute to fossil fuel exhaustion. Biodiesel has been widely developed as a replacement for conventional diesel to resolve the issue. Biodiesel production from waste cooking oil (WCO) was carried out via the transesterification process using two types of bentonite catalysts, which are raw bentonite and NaOH/bentonite. By using the impregnation method, the NaOH/bentonite catalyst was synthesized at 60°C for 12 hours. The transesterification was conducted with 0.5wt% of catalyst, at 15:1 (methanol- to-oil), for 2 hours at different reaction temperatures. The characterization of both raw bentonite and NaOH/bentonite was done using X-ray Diffraction (XRD) and Brunauer, Emmett, Teller (BET) surface characterization. A high yield of FAMEs (72%) was found to be obtained in continuous stirring at 55ºC for 2 hours and 15:1 methanol/oil molar ratio with 0.5wt.% (0.15g) of NaOH/bentonite catalyst.