Muhammad Rahimi Yusop

Development of a New Binary Solvent System Using Ionic Liquids as Additives to Improve Rotenone Extraction Yield from Malaysia Derris sp.

Rotenone is one of the prominent insecticidal isoflavonoid compounds which can be isolated from the extract of Derris sp. plant. Despite being an effective compound in exterminating pests in a minute concentration, procuring a significant amount of rotenone in the extracts for commercialized biopesticides purposes is a challenge to be attained. Therefore, the objective of this study was to determine the best ionic liquid (IL) which gives the highest yield of rotenone. The normal soaking extraction (NSE) method was carried out for 24 hrs using five different types of binary solvent systems comprising a combination of acetone and five respective ionic liquids (ILs) of (1) [BMIM] Cl; (2) [BMIM] OAc; (3) [BMIM] NTf2; (4) [BMIM] OTf; and (5) [BMPy] Cl. Next, the yield of rotenone, % (w/w), and its concentration (mg/mL) in dried roots were quantitatively determined by means of RP-HPLC and TLC. The results showed that a binary solvent system of [BMIM] OTf + acetone was the best solvent system combination as compared to other solvent systems ( ). It contributed to the highest rotenone content of 2.69 ± 0.21% (w/w) (4.04 ± 0.34 mg/mL) at 14 hrs of exhaustive extraction time. In conclusion, a combination of the ILs with a selective organic solvent has been proven to increase a significant amount of bioactive constituents in the phytochemical extraction process.

Separation of free fatty acids from high free fatty acid crude palm oil using short-path distillation

The separation of free fatty acids (FFAs) was done by using short-path distillation (SPD). The separation parameters was at their boiling points, a feed amount of 2.3 mL/min, an operating pressure of 10 Torr, a condenser temperature of 60°C, and a rotor speed of 300 rpm. The physicochemical characteristics of oil before and after SPD were determined. The results showed that FFA % of 8.7 ± 0.3 and 0.9 ± 0.1 %, iodine value of 53.1 ± 0.4 and 52.7 ± 0.5 g I2/100 g, hydroxyl value of 32.5 ± 0.6 and 13.9 ± 1.1 mg KOH/g, unsaponifiable value of 0.31 ± 0.01 and 0.20 ± 0.15%, moisture content of 0.31 ± 0.01 and 0.24 ± 0.01 % for high free fatty acid crude palm oil before and after distillation, respectively. Gas chromatography (GC) results showed that the major fatty acids in crude palm oil (CPO) were palmitic acid (44.4% - 45%) followed by oleic acid (39.6% - 39.8%). In general, high free fatty acid crude palm oil after molecular distillation (HFFA-CPOAM) showed admirably physicochemical properties.

Controlled Release Electrochemical Synthesis and Cytotoxicity Study of Copper(II) Nanoparticles in Copper(II) Decanoate Complex

In the present study, a controlled release electrochemical (CRE) technique based on the controlled release of Cu2+ ion from Cu anode in the presence of decanoic acid (HDe) has been used to synthesize Cu(II) decanoate (CuDe2) complex. The effect of applied voltages (1–10V) and electrolyte concentrations (0.1–2.0M CH3COONH4) during the electrolysis on the nanoparticles obtained was studied using TEM. The results reveal that small-sized nanoparticles (2±1nm) were obtained by using lowest applied voltage and CH3COONH4 concentration (1V and 0.1M, respectively). The smallest nanoparticle obtained was then used in the cytotoxicity study against A549 and HeLa cells. The synthesized complex gives moderate cytotoxic effect on the selected cells (IC50=15.85μM and 20.89μM, respectively) and low cytotoxic effect on normal cells (IMR90). Apoptosis is the mode of cell death based on the apoptosis assay that has been conducted.

Effect of Applied Voltage on Slow-Release of Cu(II) Ions on the Synthesis of Copper(II) Stearate Complex by Electrochemical Technique

ion from electrochemical oxidation of a Cu anode in the presence of stearic acid (HSt) and an aqueous solution of ammonium acetate (CH 3 COONH 4 ) (0.1 mol L-1) as supporting electrolyte has been used to synthesize Cu(II) stearate (Cu(II)St) complex. Different values of applied voltages (1, 5 and 10 V) were used during the synthesis to study the effect of applied voltage on the particle size of the Cu nanoparticles and morphology of the synthesized Cu(II)St complex. By using 1 V of applied voltage, small Cu nanoparticle was produced with an average particle size of 2.49 ± 0.82 nm, followed by 5 V (3.61 ± 1.18 nm) and 10 V (6.64 ± 2.72 nm). Another advantage of using 1 V of the applied voltage is the formation of well-shaped petal-like structures of the Cu(II)St complex compared to the synthesis using 5 V and 10 V which inhibit the formation of well-shaped petal-like structure. This proves that the slow-release electrochemical synthesis using lower value of applied voltage has successfully resulted in the formation of small size Cu nanoparticles.

Carbon Dioxide Adsorption and Desorption Study Using Bimetallic Calcium Oxide Impregnated on Iron (III) Oxide

Bimetal adsorbent system of calcium oxide impregnated on iron (III) oxide were evaluated as a potential source of basic sites for CO2 capture. The adsorbents were prepared by impregnation method were calcined at 200 until 600 °C. Several characterizations were carried out using XRD, BET and CO2-TPD analysis. The CaO loading increased the basicity of the adsorbent significantly enhance the CO2 chemisorption. Furthermore, it drastically reduced the desorption temperature to 310-490 °C, which is important in chemisorption aspect. The CaO/Fe2O3200 which calcined at 200 °C was found to be most efficient. The CO2 chemisorption (81.29 mg CO2/g adsorbent) was contributed most compared to physisorption (4.64 mg CO2/g adsorbent).

Electrochemical synthesis and in vitro cytotoxicity study of copper(II) carboxylates with different fatty acid alkyl chain lengths

In the present study, an electrochemical technique based on the release of Cu2+ ions from a Cu anode in the presence of unsaturated fatty acids with different alkyl chain lengths has been used to synthesize Cu(II) carboxylates. The fatty acids used in this study are lauric acid (C12 : 0) and stearic acid (C18 : 0). Optimum electrolysis conditions for the synthesis of Cu(II) laurate (CuLa2) and Cu(II) stearate (CuSt2) have been determined to maximize percentage yield and minimize energy consumption and loss of the Cu anode. We observe that both compounds (99.21%) are produced with lower energy consumption (∼21.01 W h L−1) and anode loss (∼0.57 mg L−1) by using the same optimum conditions of 10 V of applied voltage for 4 hours of electrolysis time in 0.1 M CH3COONH4 electrolyte solution. The cytotoxicity study on selected tumor cells (A549 and HeLa) shows that the synthesized compounds have moderate cytotoxic effects with IC50 in the range from 19.50 to 44.67 μM. CuLa2 with C12 alkyl chains provides better cytotoxicity effect on the selected tumor cells due to lower IC50 than CuSt2 with C18 alkyl chains. This shows that the length of alkyl chain also affects the compound toxicity towards selected tumor cells.

Effect of metals compatibility on fluorine-doped tin oxide catalyst for glycerol conversion to 1,2-propanediol

The effect of metals on support material fluorine-doped tin oxide (FTO), were studied. A series of metals such as ruthenium (Ru), osmium (Os), palladium (Pd), and copper (Cu) on FTO support were prepared by a simple wet mixture method, and attempted as a heterogeneous catalyst to enhance the hydrogenolysis of glycerol converted to 1,2-propanediol (1,2-PDO). The physicochemical properties of the catalysts were characterized by XRD, XPS, BET, FESEM, TEM, TPR, and TPD techniques. In particular, the catalyst of Ru-FTO was recorded as a good catalyst with an optimum glycerol conversion of 100% and 1,2-PDO selectivity of 94% respectively. It was suggesting that the acid an basic properties of the catalyst could achieved the C-O and C-H bond dissociation by formation of different intermediates of acetol and acetaldehyde to become 1,2-PDO. Despite that, some reaction parameters were evaluated and optimized reaction condition were established

Development of α-Fe2O3 as Adsorbent and its Effect on CO2 Capture

Iron oxide (α-Fe2O3) as adsorbent was no longer new in CO2 adsorption studies. However, its contributions in the industry still in limited wherein lack of convincing results of quantifying of adsorbed CO2. This work presents an analysis for α-Fe2O3 was prepared by simple mixing method with identified the adsorption capacity that applied in CO2 capture. The synthesized α-Fe2O3 from different concentrations of precursor were analyzed using XRD, N2 adsorption-desorption isotherms with BET and BJH method, TEM, FTIR, CO2 adsorption at 298 K, CO2-TPD and TGA-DTG. It was noted that 2M concentration of precursor (s2M) with highest crystallite peaks shows highest surface area among all samples which indicative of well generated pores. The different concentration of precursor was found generated more porosity rather than particle size according to TEM micrograph. The sphere shape crystallite particle with high surface area (50.5 m2/g) and porosity were desirable properties in CO2 adsorption. Consequently, physically adsorbed CO2 with adsorption at 298 K was highest with adsorption capacity of at 17.0 mgCO2/gadsorbent. Finally, chemically adsorbed CO2 was successfully identified from CO2–TPD analysis with adsorption capacity of 0.19 mgCO2/gadsorbent and 1.31 mgCO2/gadsorbent at maximum desorption temperature of 375 °C and 749 °C respectively.

Low frequency sonochemical synthesis of nanoporous amorphous manganese dioxide (MnO2) and adsorption of remazol reactive dye

Nanoporous amorphous-MnO2 was synthesized by sonochemical process (sonication) on the solid manganese (II) acetate tetrahydrate (Mn(CH3COO)2.4H2O) in 0.1 M KMnO4. The product was characterized by X-ray diffraction (XRD), morphology of the material was scanned by Field Emission Scanning Electron Microscopy (FE-SEM) and absorptions of MnO2 bonding was characterized by Fourier Transform Infra-Red Spectrometer (FT-IR). Remazol reactive dye or Red 3BS, was used in the adsorption study using nanoporous amorphous-MnO2. In batch experiment, 10 ppm of Remazol reactive dye was used and experiment was carried out at room temperature. Adsorption of Remazol dye on 0.2g synthesized nanoporous amorphous-MnO2 showed 99 – 100% decolorization.

COD and color removal of reactive orange 16 dye solution by electrochemical oxidation and adsorption method

Degradation of Reactive Orange 16 (RO16) dye was investigated using electrochemical oxidation and adsorption (batch method) using mixture of coconut trunk charcoal-graphite-tin-polyvinyl chloride(PVC). In batch studies for adsorbents pellet and powder form of the charcoal mixture were used. RO16 was chosen as the model dye because of its high resistance towards conventional treatment methods. NaCl and RO16 concentration, treatment duration, weight of electrode and adsorbent and volume of solution were kept constant for both methods. The effectiveness of the treatments were compared and evaluated by percentage of RO16 decolorization and chemical oxygen demand (COD) removal and results indicated that electrochemical oxidation method ables to decolorized RO16 dye up to 98.5% after 20 minutes electrolysis time while pellet and powder in batch method only removed 17.1 and 33.6% of RO16 color respectively. However, only 45.6% of COD can be removed using electrochemical oxidation method while pellet and powder i...