Abu Masykur

Zinc/Itaconate Coordination Polymers as First Examples with Long-Lasting Phosphorescence Based on Acyclic Ligands

Two novel coordination polymers (CPs) based on zinc(II) and acyclic dicarboxylate linkers, i.e. [Zn2(μ3-IA)2(H2O)4]n (1-W) and {[Zn2(μ-IA)2(DMF)]·H2O}n (2-DMF) (where IA2− = itaconate) have been obtained as a result of a systematic study of some synthetic factors such as pH and solvents, which has allowed optimizing the conditions that render the best yields. 1-W is obtained as X-ray quality single crystals upon which diffraction analysis has been conducted, showing that it consists of a neutral 2D layered structure. Some structural details have been elucidated for 2-DMF based on a comparison of PXRD data with 1-W and in view of the similar composition of both crystalline phases. Photoluminescence (PL) measurements confirm that 2-DMF presents slightly different spectra from those of 1-W. Time-dependent density functional theory (TD-DFT) calculations of 1-W reveal that electronic transitions arise from both first excited singlet and triplet states involving ligand-centred emissions. Moreover, both compounds exhibit blue fluorescence and green phosphorescence that involves less frequent long-lasting phosphorescence (LLP) at 10 K. Exhaustive characterization of long-lasting phosphorescence by means of time-resolved spectroscopy reveals remarkably long lifetimes (τ) of ca. 352 ms (λem ≈ 550 nm) for 1-W and 547 ms (λem ≈ 500 nm) for 2-DMF.

Silylation and characterization of microcrystalline cellulose isolated from indonesian native oil palm empty fruit bunch

Silylation of microcrystalline cellulose (MCC), isolated from Indonesian native oil palm empty fruit bunch (OPEFB), using aminosilane compound synthesized through aminolysis of 3-glycidoxypropyltrimethoxysilane (GPTMS) with ethylenediamine (EDA) has been conducted in this study. Generally, there are three steps performed to isolate MCC before silylation process, i.e. bleaching, alkaline treatment and acid hydrolysis. All products resulted from bleaching, alkaline and acid hydrolysis treatments were characterized using Fourier Transform Infrared (FTIR) spectroscopy. Two conditions were optimized in this study which they were an acid concentration in hydrolysis process and aminosilane ratio in silylation process. The preliminary study regarding optimizing acid hydrolysis process by varying sulfuric acid concentration was obtained an optimum sulfuric acid concentration by 45% having highest crystallinity index (CI) measured using x-ray diffraction (XRD) data. The morphological structure of MCC was rod-like crystalline structure confirmed by transmission electron microscopy (TEM). The silylating agent was varied in this study with the ratio to MCC by 1:1, 3:1 and 5:1 mmol g-1. Based on loading analysis, the aminosilane with ratio 1:1 mmol g-1 was noted as optimum concentration having high loading yield by 79.2%. Effect of silylation on MCC properties was, on the one hand, it decreased the CI and crystallite size, however, on the other hand, it increased the surface area and pore volume.

Cross-linking of succinate-grafted chitosan and its effect on the capability to adsorb Pb(II) ion

The aim of this research was to improve the adsorption capacity of chitosan by modification of the chitosan using various cross-linking agents and followed by grafting using succinate anhydride. Succinate anhydride was grafted into chitosan that had been cross-linked using ethylene glycol di-glycidyl ether (EGDE), diethylene glycol diglycidyl ether (DEGDE) andbisphenolAdiglycidyl ether (BADGE) on the hydroxyl group of chitosan to yield Chit- EGDE-Suc, Chit-DEGDE-Suc, and Chit-BADGE-Suc, respectively. Modified chitosans were analyzed using FTIR and TG-DTA and then applied as adsorbents for Pb(II) ion. Adsorption was carried out in batch condition with a variation of solution pH, contact time, and concentration of Pb(II) in the solution. Adsorption ofPb(II) ion reached optimum condition at pH 5 and contact time of 120 minutes. Adsorption of Pb(II) ion on all of the adsorbents fit well the pseudo-second order kinetic equation. Adsorption capacities of Pb(II) on Chit-EGDE-Suc, Chit-DEGDE-SucdanChit-BADGE-Suc were 0.333, 0.388 and 0.898 mmolg-1, respectively, which mean that the adsorption of Chit-BADGE-Suc was the highest and followed by Chit- DEGDE-Suc and Chit-EGDE-Suc.

Preliminary Study of Bio-Impedance Based Sensor Using Organic Polymer Membrane for Identification of Pork and Beef

Bio-impedance based sensor using organic polymer-membrane was presented in this paper. The Ca-alginate with glycerol as plasticizer used in the experiments was fabricated by slip casting method on a glass substrates. After atmospheric heating treatment of edible films at 60°C for 24 hours, the films-membranes of 50 mm were obtained. Bio-impedance characterizations were carried out by LCR meter at room temperature. The experiment results showed that the sensor finely operated at low frequency i.e. less than 40 kHz. Response of the sensor increased with the increase of samples mass and became constant after a critical mass. Finally, bio-impedance responses of beef and pork were clearly indicated by a different magnitude that it is possible to apply the films-membranes as bio-sensor applications.

SYNTHESIS AND CHARACTERIZATION OF TRIAQUATRISULFISOKSAZOL COBALT(II)SULPHATE.nHYDRATE COMPLEX

Complex of cobalt(II) with sulfisoxazole (slfs) has been synthesized in 1 : 4 mole ratio of metal to ligands in methanol, the complex formula is [Co(slfs)3(H2O)3]SO4.nH2O. The electric conductivity of the complex in methanol correspond to 1:1 electrolyte. The thermal analysis indicates that complex contain some hydrates. Magnetic Susceptibility measurements show that the complex is paramagnetic with eff = 4,60(9) BM. Infra red spectra indicates that the primary N-H group coordinated to the center ion, it is signed by a shift of primary N-H group absorption. UV-Vis spectrum appears one peak at = 515,5 nm (19.342 cm) due to transition peak of 4T1g (F)  4 T2g (P) (3) overlay to transition peak of 4T1g(F)  4A2g(F) (2) . The value of 10 Dq (o) that corresponds to transition 4 T1g  4 T2g (1) is 95,29 kJ.mol -1 . Cyclic voltammograms have revealed quasi reversible. The complex probably is octahedral.