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This research prepared a TiO2, ZnS, and ZnS-TiO2 film on a carbon fiber, to produce TiO2/C-fiber, ZnS-C-fiber, and ZnS-TiO2/C-fiber by Chemical Bath Deposition (CBD). Results show that TiO2/C-fiber consist of anatase at 2θ 25.3 o and 54.6 o, rutile at 2θ 43.5 o and a carbon characteristic peak at 2θ of 24.5 o. Meanwhile, the characteristic peaks of ZnS on ZnS-TiO2/C-fiber present at 2θ of 27.91 o and 54.58 o. TiO2/C-fiber has a band gap energy of 3.60 eV, the ZnS/C-fiber of 3.73 eV; when those two catalyst combine, the gap energy is 3.15 eV indicating the interface charge transfer between ZnS-TiO2. Photocatalytic treatment of an isopropanol solution with TiO2/C-fiber as a catalyst and under UV light radiation present results peaks at 222- 224 nm and 265 nm, indicating the electronic transition of acetone. Meanwhile, the isopropanol degradation with ZnS-TiO2/C-fiber produced a new peak at 234-237 nm. The Quantum Yield, QY, of ZnS-TiO2/C-fiber is 6.96 x 10-4, higher than TiO2/C-fiber, i.e., 0.42 x 10-4. It indicates that ZnS provides a significant role in the photocatalytic activity through a red shift of light response and decreasing electron-hole recombination.

This study aims to fabricate bio-composites of hydroxyapatite/shellac/sorghum as bone scaffold material in biomedical applications. Hydroxyapatite is made from bovine bone powder, while shellac is the end product from processing lice with adhesive properties, which are biodegradable and non-toxic. Furthermore, sorghum was used as a pore-forming material. The production of the materials was carried out using dry method which was sintered at a temperature of 1000°C. Subsequently, characterization of the bio-composites was carried out through X-Ray Diffraction, Scanning Electron Microscopy and Fourier Transform Infrared. The results of hardness and compression test were compared using pure hydroxyapatite and human bone as gold standard material. Furthermore, the biodegradation rate of these materials was also reported.

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.

The modification of carbon-based nanomaterials with metals is widely studied due to its unique properties. Here, the modification of carbon nanomaterial with iron oxide has been successfully carried out. This modification was achieved using arc discharge in 50% ethanol liquid media. The anode used in the arc discharge was prepared from a mixture of carbon and iron oxide that was synthesized in electrolysis and was then calcined at 250°C with silicon binder with a mass ratio of 3:1:1, and the cathode used was graphite rod. Both electrodes were set in the nearest gap that could provide an arc during arc-discharging, leading to carbon-based nanoparticle formation. The diffractogram pattern of the X-ray diffraction of the fabricated nanoparticles confirmed the typical peak of carbon, iron oxide and iron. The magnetization value of the result analysis of the vibrating sample magnetometer was 9.9 emu/g. The bandgap energy measurement using diffuse reflectance ultra violet was estimated to be 2.18 eV. Using the transmission electron microscopy, the structure of the nanomaterial produced was observed as carbon-encapsulated iron compound nanoparticles.

A Research on CdS synthesis in reverse microemulsion of Igepal CO-720 system has been conducted at various weight ratio of water to surfactant. Igepal CO-720 naturally forms oil in water (o/w) emulsion type due to its high HLB (Hydrophilic -Lipophilic Balance) value. Therefore, in this research the Igepal CO-720 system was inversed into water in oil (w/o) system before it was used as microreactor for CdS synthesis. As comparison, a system of AOT (Aerosol OT; sodium bis (2-ethylhexyl) sulfosuccinate) which is naturally w/o system was also used as microreactor for CdS synthesis. The prepared CdS was analyzed by X-ray diffraction for crystal identification, scanning electron microscope for morphological analysis, UV-Vis for absorption edge determination and photoelectrochemical testing for photoactivity. The results show that the Igepal CO -720 system can be inverted into w/o system and can be used as microreactor for CdS synthesis. The prepared CdS is in nanosize with the average diameter of 2.517 ± 0.014 nm and the average gap energy of 3.805 ± 0.178 eV. The prepared CdS in Igepal CO-720 system has less regular form in comparison with morphology of the prepared CdS in AOT system. As the ω values decreases the particle diameter decreases, the gap energy increases and the % IPCE increases. It indicates that high surfactant concentration allows small size micelles formation and produced smaller CdS particle that has high surface area and therefore provide higher photocatalytic activity which was indicated by high value of its % IPCE.

Study on chitosan modification by swelling and crosslinking and its application as a selective adsorbent for heavy metals Cr (VI) in batik industry wastes was done. Swelling is intended to improve chitosan porosity, whereas crosslinking is to increase the resistance of chitosan against acid. Natural samples are generally acidic, thus limiting chitosan application as an adsorbent. Modification of chitosan by combining swelling and crosslinking is expected to increase its adsorption capacity in binding heavy metal ions in water. The modified chitosan was later contacted with Cr (VI) to test its adsorption capacity with a variation of pH and contact time. Finally, application of modified chitosan was done in batik industry waste containing Cr (IV). Based on the results, chitosan-ECH 25% (v/v) was the optimum concentration of crosslinker to adsorb Cr (VI) ions. Modified chitosan has a solubility resistance to acids, even though a strong acid. Modification of chitosan also improved its adsorption capacity to Cr (VI) from 74% (pure chitosan) to 89% with contact time 30 min at pH 3. On the application to the batik wastes, the modified chitosan were able to adsorb Cr (IV) up to the level of 5 ppm. Thus, the modified chitosan has a potential to be applied to as an adsorbent of Cr (VI) in batik industry wastes.

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.