Ridzuan Ramli

Facile synthesis of copper nanoparticles in glycerol at room temperature: formation mechanism

A copper sol is usually synthesized by the reduction of a copper precursor with a suitable reducing agent in the presence of a stabilizer. There are few reports regarding the preparation of copper nanoparticles in glycerol without using a stabilizing agent, but at elevated temperatures. The formation of reduced copper (Cu0) is usually verified by a UV-vis spectrophotometer where a ‘red copper sol’ was formed. In the present paper we synthesized the copper sol at room temperature in a glycerol medium using hydrazine as a reducing agent. The chemical states of copper in the sol and their composition were analyzed by X-ray absorption near edge structure spectroscopy (XANES) with the linear composition fitting method. A series-parallel mechanism of the reaction was proposed. An average particle size of 5 ± 1 nm was visualized via transmission electron microscopy (TEM).

Synthesis of Copper Nanoparticles at Room Temperature Using Hydrazine in Glycerol

Copper nanoparticles (CuNPs) have been prepared by the reduction of copper chloride in glycerol using hydrazine at ambient conditions. The reduction process takes place under vigorous stirring for 8 h. The formation of CuNPs and size were confirmed by UV/Vis analysis and TEM imaging respectively. The experiment result showed that, 7.062 mM of hydrazine solution and 0.0147 mM of Cu2+ solution were needed to synthesize narrow size monodisperseCuNPs.The presence of nanoparticle was found after an induction period of 4 h and further reaction time, complete Cu0 state nanoparticle was obtained as deep red wine colour was observed. Stability study of CuNPs showed that the nanoparticles were stable up to 4 days. The particle size of the nanoparticles have been analysed by transmission electron microscopy (TEM) and the average size of CuNPs was in the range 2 to 10 nm.

Tailoring base catalyzed synthesis of palm oil based alkyd resin through CuO nanoparticles

Palm oil based alkyd resin was synthesized by an alcoholysis–polyesterification process over a base catalyst tailored by copper oxide (CuO) nanoparticles. In the present paper we synthesized CuO sol in glycerol and subsequently used it in alkyd resin synthesis. The formation of the alkyd resin was confirmed by FTIR, Raman, 1H-NMR and 13C-NMR methods and its molecular weight was determined by gel permeation chromatography (GPC). The antimicrobial activity of the pseudo-homogeneous additive was determined via the Kirby–Bauer method and the stability of the CuO was determined by X-ray absorption near edge structure spectroscopy (XANES). The addition of CuO nano-sol to the conventional homogeneous base catalyzed system explored a new catalytic route for the preparation of bioresin from vegetable oil, reducing the reaction time as well as adding antimicrobial properties to the resin.

Spherical Nanocrystalline Cellulose (NCC) from Oil Palm Empty Fruit Bunch Pulp via Ultrasound Assisted Hydrolysis

Nanocrystalline cellulose (NCC) was isolated from oil palm empty fruit bunch pulp (EFBP) using ultrasound assisted acid hydrolysis. The obtained NCC was analysed using FESEM, XRD, FTIR, and TGA, and compared with raw empty fruit bunch fibre (REFB), empty fruit bunch pulp (EFBP), and treated empty fruit bunch pulp (TEFBP). Based on FESEM analysis, it was found that NCC has a spherical shaped after acid hydrolysis with the assistance of ultrasound. This situation was different compared to previous studies that obtained rod-like shaped of NCC. Furthermore, the crystallinity of NCC is higher compared to REFB and EFBP. According to thermal stability, the NCC obtained shows remarkable sign of high thermal stability compared to REFB and EFBP.

Glycerolysis of palm oil using copper oxide nanoparticles combined with homogeneous base catalyst

In the present work, a new catalyst system composed of copper oxide nanoparticles (CuO-nano) along with a conventional homogeneous base catalyst (NaOH) for the glycerolysis of palm oil to produce monoglycerides (MG) was proposed. CuO-nano was synthesized in glycerol and directly used in the glycerolysis reactions, which formed a pseudo-homogeneous system. The production of MG and diglycerides (DG) from oil was monitored by using 1H-NMR, 13C-NMR and HPLC. When compared with the conventional NaOH catalyst, CuO-nano used alone showed less activity, but adding NaOH to the CuO-nano exhibited a synergistic effect by increasing the MG yield significantly. The oil conversion, MG and DG yield were achieved at 95, 71 and 24%, respectively, for the new catalyst system composed of CuO-nano and NaOH. The mechanism of the glycerolysis reaction over CuO-nano and NaOH was elucidated.