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The edible film of chitosan-alginate in this study showed characteristics of the physical and mechanical properties when various plasticizers of polyethylene glycol/PEG, polyvinyl alcohol/PVA, and glycerol were added into the origin film. It was also found that chitosan content in the edible film contributed to the change in the physical properties and the conductivity of the film. The general effect on the film because of the addition of plasticizers was the decrease of the tensile strength, the increase of the films' elongation, and the increase of the water vapor permeability (WVP). Among other plasticizers, PEG attracted the most attention in which it affected the most significant change on the properties. Meanwhile, the higher chitosan content in the chitosan-alginate film affected the increase of the tensile strength and the decrease of the elongation value, and the decrease of the WVP on the film. Characterization using FT-IR spectrophotometer showed that no chemical interaction was formed due to the mixing of alginate-chitosan in the film. Instead, only the physical blending of chitosan-alginate was formed in the edible film.

Electrocatalytic parameters of a Pt/C standard and a sample of terbium(III) monoporphyrinato were investigated in different solutions. N electron transfer, Tafel slope, Eonset, and overpotential of the catalyst of Pt/C in different solutions were calculated and analyzed using a rotating ring disk electrode (RRDE) in 0.5 M H2SO4, 0.1 M HClO4 and 0.1 M NaOH. In the RRDE measurements, a bipotentiostat at a potential range of 1.03 to 0.05 V vs RHE (Ering = 1.2 V vs RHE) with a scan rate of 5 mV/s and rotation rates of 200, 400, 900, 1600 and 2500 rpm was used. Hereafter, the test of terbium(III) monoporphyrinato compound formulated in [Tb(TPP)(cyclen)]Cl (TPP = 5,10,15,20-tetraphenylporphyrinato; cyclen = 1,4,7,10-tetraazacyclododecane) as a candidate material for ORR electrocatalyst was also done. The results showed that the measurement of Pt/C standards was satisfactory according to the literature for all parameters with the n electron transfer close to 4 in all electrolytes media. [Tb(TPP)(cyclen)]Cl had an n electron transfer value of 2.38, suggesting that the [Tb(TPP)(cyclen)]Cl compound has less potential for ORR catalysts.

Penelitian ini bertujuan untuk memodifikasi kitosan dan digunakan sebagai sensor ion logam Cu(II). Modifikasi dilakukan dengan penaut silang kitosan menggunakan tripolifosfat dan dibentuk menjadi membran. Membran yang dihasilkan dianalisis dengan spektrofotometer UV-Vis, Fourier Transform InfraRed (FTIR), dan Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX). Hasil analisis menunjukkan keberhasilan sintesis membran kitosan/tripolifosfat (CTS/TPP). Membran CTS/TPP dapat mendeteksi ion logam Cu(II) ditandai adanya perubahan warna membran dari bening menjadi biru. Keberhasilan deteksi ion logam Cu(II) oleh membran dikonfirmasi oleh pengujian UV-Vis, FTIR dan SEM-EDX. Pengujian spektrofotometer UV-Vis pada membran setelah dikontakkan dengan ion logam Cu(II) menunjukkan terjadinya pergeseran panjang gelombang maksimum akibat interaksi yang terjadi antara membran dengan ion logam Cu(II). Pada penentuan kondisi optimum pH, membran CTS/TPP optimum bekerja pada pH 7 dalam waktu 15 menit. Pada rentang konsentrasi ion Cu(II) 1‒10 ppm, nilai koefisien korelasi (R2) untuk membran CTS/TPP diperoleh sebesar 0,9917. Modification of Tripolyphosphate Cross-Linked Chitosan Membrane for Cu(II) Ion Sensor. This study aims to modify chitosan and use it as a sensor for Cu(II) metal ions. The modification was carried out by cross-linking chitosan using tripolyphosphate and forming it into a membrane. The resulting membranes were analyzed by UV-Vis, FTIR spectrophotometer, and SEM-EDX. The analysis results show the successful synthesis of the chitosan/tripolyphosphate (CTS/TPP) membrane. The CTS/TPP membrane can detect Cu(II) metal ions, as indicated by a change in the color of the membrane from clear to blue. The successful detection of Cu(II) metal ions by the membrane was confirmed by UV-Vis, FTIR spectrophotometer, and SEM-EDX. UV-Vis spectrophotometer testing on the membrane after contact with Cu(II) metal ions showed that the maximum wavelength was shifted due to the interaction that occurred between the membrane and Cu(II) metal ions. In the determination of the optimum pH condition, the CTS/TPP membrane optimally works at pH 7 for 15 minutes. In the Cu(II) concentration range of 1‒10 ppm, the correlation coefficient (R2) value for the CTS/TPP membrane was 0.9917.

This paper reports the synthesis of Fe(II)/Co(II) fused triphenyl porphyrin dimers as candidate of hybrid organic metal electrocatalyst. The synthesis was conducted in five-step reactions using the starting materials pyrrole and benzaldehyde. The fuse oxidative reaction was done via free-base form of triphenyl porphyrin to omit metal insertions/removals of intermediate products. This strategy is very beneficial for the synthesis of metal fused triphenyl porphyrin that needs less reactions where phenyliodine(III) bis(trifluoroacetate) (PIFA) was successfully deployed in the oxidative reaction of two free-base triphenyl porphyrins. Here, the comparisons of NMR spectra were presented to see the changes of the starting material to the product. Initial electrochemical tests showed that reduction current of planar structure of Fe/Co fused triphenyl porphyrin dimer was on the potential range at -1.10 V to 0.45 V vs Au. Fe-fused triphenyl porphyrin dimer with 7.58 × 10–4 A (-1.05 V) showed slightly better performance than Co-fused triphenyl porphyrin dimer with 5.67 × 10–4 A (-0.97 V).

Banyaknya pencemaran ion logam dalam perairan menjadi perhatian yang serius para peneliti, terutama untuk mengurangi keberadaan ion logam Cd yang terkandung dalam perairan dengan menggunakan adsorben. Oleh karena itu, penelitian ini bertujuan untuk membuat adsorben berbasis silika dengan kapasitas dan selektifitas tinggi terhadap ion Cd(II). Dalam penelitian ini, sintesis material imprinted ionic Cd(II) (SiO2-TMPDT-Cd-Imp) telah berhasil dilakukan menggunakan prekursor natrium silikat dari abu sekam padi. Proses sintesis diawali dengan pembuatan natrium silikat. Selanjutnya, trimetoksisililpropildietilentriamin (TMPDT), ion logam Cd(II) dan HCl ditambahkan hingga terbentuk gel. Gel dielusi dengan etilenadiaminatetraasetat (EDTA) untuk membentuk cetakan (template). Hasil karakterisasi dengan FTIR menunjukkan TMPDT terikat pada silika ditandai dengan munculnya vibrasi ulur dari C-H alkana pada 2908 cm-1 dan vibrasi tekuk gugus N-H pada 1471 cm-1. Karakterisasi dengan Surface Area Analyzers (SAA) menunjukkan bahwa material tersebut memiliki luas permukaan sebesar 12,674 m2/g, volume pori total sebesar 0,017 cc/g, dan jari-jari pori rerata sebesar 18,783 Å. Karakterisasi dengan SEM-EDX memperlihatkan adanya unsur C dan N pada SiO2-TMPDT-Cd-Imp. Kondisi optimum adsorpsi ion logam Cd(II) oleh SiO2-TMPDT-Cd-Imp terjadi pada pH 6, waktu kontak 10 menit dan konsentrasi awal sebesar 10 ppm. Model kinetika adsorpsi ion logam Cd(II) pada SiO2-TMPDT-Cd-Imp mengikuti pseudo orde 2. Proses adsorpsi SiO2-TMPDT-Cd-Imp cenderung mengikuti isoterm Freundlich dengan nilai faktor heterogenitas (n) sebesar 1,617 dan konstanta Freundlich (KF) sebesar 2,768. Kapasitas adsorpsi maksimum untuk Langmuir (qm) sebesar 19,16 mg/g. Urutan selektifitas (K) ion logam Cd(II) terhadap ion logam lain pada SiO2-TMPDT-Cd-Imp adalah Cd-Pb

The objective of this study is to develop and test hybrid generators harvesting both solar and mechanical energy. The hybrid generators work using photovoltaic- and piezoelectric-principles, where the active semiconductors were ZnO nanofibres synthesized by electrospinning at various feed rates of precursor. The results show that the crystallinity, crystalline size, fibre size, and fibre uniformity examined by X-ray diffraction and scanning electron microscopy were strongly affected by changing the solution flow rate among 2, 4, 6, and 8 μL/min. Meanwhile, the voltage and power generated from the hybrid generators were influenced by the crystalline quality and morphology of the ZnO fibres. The highest voltages of photovoltaic- and piezoelectric-based hybrid generators were 507 and 36.3 mV, respectively. In addition, the maximum power values of photovoltaic- and piezoelectric-based generators were 706.72 μW/cm² and 49.6 nW/cm², respectively. Therefore, hybrid generators are of interest for fabrication into self-power devices.

Endrin residues are still remain in the land field these compounds are no longer used by farmers and have been banned by the government. This residue can stay in the soil longer and persistant. Microbial enrichment is expected to accelerate the degradation of pesticide residues. Microbes stretcher are Bacillus substillis, Heliothrix oregonensis, Catenococcus thiocycli, and Achoromobacter sp obtained from the preliminary research results from soil isolation of idegenus in LIPI Cibinong Microbiology Laboratory. Soil for the planting medium obtained from the village of Karawang, Regency Cilamaya Wetan, Cilamaya District. The experiment was conducted in the field by using lysimeter at the Experiment Jakenan station from July 2013 to December 2013. The objective of the was to obtain technology of activated carbon-coated urea and biochar which enriched microbial indegenus. The experiment was used randomized block design (RCBD) with 3 replications. Plant used are rice. Insecticide residue analysis was carried out in the laboratory in Bogor Balingtan using gas wchromatography (GC), with the SNI method 06-6991.1-2004. The purpose of this study knowing the capabilities of urea coating with activated carbon enrichment microbia in reducing the concentration of residues endrin. The objective were urrea coated activated carbon from coconut shell were enriched with microbes on paddy field can lower pesticide residues of endrin until 33.65%. This carbon as the preferred home. Enrichmentwith microbial indegenuscan improve theeffectivenessof ureacoating biochar andureacoatingactivated carbon coconut shell todecrease concentration of endrin.

Polybutylene itaconate (PBI) for modification with divinyl benzene (DVB) and glycerol has been synthesized at 180 °C for 3 h via polycondensation of itaconic acid (IA) and butanediols using catalyst of Ti(OBu)4. Modification on PBI was done with addition of 15%, 20% and 25% DVB (w/w) using benzoyl peroxide. With glycerol, weight variations of glycerol:1,4-butanediol (BDO) in the synthesis were 10%, 30%, and 50% (mole/mole). PBI and PBI modified with DVB and glycerol were characterized with FTIR and TG-DTA. PBI showed a wavenumber shift from 1703 cm-1 to 1728 cm-1 of the C=O functional group from acid to esther. The DVB modification on PBI also showed that the intensity decrease of C=C stretching was due to the formation of crosslinking on the double bond. In the modification with glycerol, three dimensional networking on the polyester occurred through bonding between hydroxyl of glycerol and acid group of IA. Constant intensity of C=C stretching on polyester was seen. The thermal stability of PBI modified with DVB increased, accompanied by rigidity change of the structure. The thermal stability of PBI modified with glycerol decreased, caused by the decrease of regularity degree and the elasticity increase of the three dimensional structure of polyester.

A study of batch fermentation of green algae (Spirogyra majuscula Kuetz) from Pengging Lake, Boyolali, Central Java for bioethanol source using immobilization technique of Ca-alginate for Saccaromyces cerevisiae entrapment has been done. The scope of the study emphasized on the best condition for the processes of hydrolysis and fermentation. Concentration of sulfuric acid and hydrolysis time were varied with 0.1, 0.2, 0.3, 0.4 and 0.5 M for 30, 90, 150, 210, 270, 330, 360, 390, 420, and 450 min to obtain the maximum glucose content of UV analysis. Na-alginate : yeast ratio and fermentation time were varied with 1:5, 2:4, 3:3, 4:2 and 5:1 (w/w) for 1, 2, 3, 4, 5, 6 and 7 days. Distillation at 70-80 °C was deployed to purify the fermentation product. The ethanol content in the product was analyzed using gas chromatography-flame ionization detector (GC-FID). The result of study showed that maximum glucose content was obtained 2.1% from 0.2 M sulfuric acid for 6 h of hydrolysis. Maximum ethanol content was obtained 54.1% from 2:4 ratio of Na-alginate : yeast (w/w) for 4 days of fermentation. The study also concludes that immobilization technique of Ca-alginate increase alcohol content compared to without immobilization of green-algae fermentation.