Preparation of Ta2O5 nanoparticles by using cathode glow discharge electrolysis

Tantalum pentoxide nanoparticles (Ta2O5 NPs) were fabricated by cathode glow discharge electrolysis (CGDE) generated between a needle-like platinum wire cathode and a tantalum foil anode in 6 g L−1 Na2SO4 electrolyte solution containing 5 mL hydrofluoric acid (HF) and 0.075 g cetyltrimethyl ammonium bromide (CTAB). The chemical structure, composition and morphology of the obtained powder were analyzed by using XRD, FT-IR, SEM/EDS, XPS and UV-vis DRS. The results found that Ta2O5 NPs with orthorhombic structure and wide band gap (3.6 eV) are successfully fabricated at 500 V discharge voltage in about 3 h. CTAB as a stabilizing agent can reduce the agglomeration due to forming CTA+ and attaching the surface of the synthetic products. A possible preparation mechanism of Ta2O5 NPs is proposed. Firstly, the tantalum foil anode is oxidized to form a compact Ta2O5 layer. Then, Ta2O5 surface is etched to form soluble [TaF7]2− complexes in the presence of HF. After that, soluble [TaF7]2− complexes can react with H2O to form Ta(OH)5. Finally, Ta(OH)5 is further converted to Ta2O5 from plasma-liquid interface into solution.

OPTIMALISASI TEKNIK ISOLASI DAN PURIFIKASI DNA MENGGUNAKAN BUFFER CTAB (CETYLTRIMETHYL AMMONIUM BROMIDE) PADA TANAMAN MARKISA (Passiflora sp.) DATARAN RENDAH KABUPATEN JENEPONTO

Penelitian ini bertujuan untuk mendapatkan prosedur metode CTAB dan metode purifikasi DNA yang tepat untuk menghasilkan kuantitas dan kualitas DNA yang baik yang berasal dari tanaman markisa dataran rendah. Penelitian ini dilaksanakan di dua tempat, yaitu kabupaten Jeneponto untuk pengambilan sampel tanaman markisa dan untuk pengisolasian dan pengujian DNA dilakukan di Laboratorium Biosains dan Sumber Daya Hayati Tanaman Program Studi Agroteknologi Jurusan Budidaya Pertanian Fakultas Pertanian Universitas Hasanuddin Makassar. Penelitian ini berlangsung dari bulan September 2013 hingga Desember 2013. Penelitian dilaksanakan dalam enam metode isolasi DNA dengan menggunakan larutan CTAB, pengujian kualitas serta kuantitas DNA, pemurnian (purifikasi) DNA pada hasil isolasi terbaik, dan pengujian kualitas serta kuantitas pada hasil pemurnian. Berdasarkan uji kualitas dan kuantitas, berat sampel sebesar 0,200 g, suhu inkubasi hasil ekstraksi pada suhu 65oC selama 30 menit, dan kecepatan sentrifugasi sebesar 12.000 rpm selama 10 menit dapat menghasilkan DNA yang memiliki kemurnian yang cukup baik dan tampak pita DNA yang cukup tebal berkisar 1500 – 5000 kb setelah hasil isolasi DNA dielektroforesis. Sedangkan pemurnian kembali menggunakan kloroform : isoamylalkohol, isopropanol, dan ethanol 70% menunjukkan kualitas dan kuantitas DNA yang baik.

INTERACTIONS BETWEEN CETYLTRIMETHYLAMMONIUM OR TETRAMETYLAMMMONIUM BROMIDE AND MCl2 OR MCl5 (M = Hg, Cu, Zn, Co, Ni, Cd and Nb) IN MONONUCLEAR COMPLEXES: SYNTHESIS AND INFRARED STUDY

On allowing cetyltrimethyl ammonium bromide (C19H42NBr) and HgCl2, CuCl2.2H2O, CoCl2.6H2O, ZnCl2, NiCl2.6H2O or NbCl5 in specific ratio in methanol, new mononuclear have been obtained and studied by infrared. The suggested structures are discrete, of infinite chain with octahedral or tetrahedral environments around the metallic centres. The MX2 behaves as discrete chains. For most of the structures, when intermolecular hydrogen bonds are considered, supramolecular architectures may be obtained.

A KINETIC STUDY ON THE OXIDATION OF MALIC ACID BY CHLORAMINES - T IN MICELLAR SYSTEM

The oxidation of malic acid by chloramine –T with the presence of cationic surfactant e.g.,cetyltrimethyl ammonium bromide (CTAB) in acetic acid medium has been studied. Thereaction shows first order with respect to [CAT] and fractional order with respect to[Substrate]. The reaction rate decraeses with increase in concentration of acetic acid. Thereaction has retarding effect on the addition on product (P-Toluene Sulphonamide). Theactivation parameters evaluation has been on the basis of temperature variations studied.A literature survey reveals that very limited information have been available on the oxidationof malic acid by CAT in micellar system1. This has prompted us to undertake a kinetic studyon this reaction.

Effects of Bentonite Nanoclay and Cetyltrimethyl Ammonium Bromide Modified Bentonite Nanoclay on Phase Inversion of Water-in-Oil Emulsions

The effects of unmodified and modified bentonite nanoclays (with various degrees of surfactant modification) on the catastrophic phase inversion from water-in-oil (W/O) emulsion to oil-in-water (O/W) emulsion were determined experimentally. The bentonite nanoclay (NC-Bt) was suspended in the aqueous phase, and the critical volume fraction of water where phase inversion from W/O to O/W emulsion took place was determined through conductivity measurements. Cetyltrimethyl ammonium bromide (CTAB) was used as a surfactant to modify the nanoclay. The adsorption of CTAB onto nanoclay had a strong influence on the contact angle and the critical volume fraction of water where phase inversion took place. The modification of the nanoclay brought about by the adsorption of CTAB increased the three-phase contact angle (measured through the aqueous phase), thereby making it more hydrophobic, and prolonged the phase inversion point. CTAB alone and CTAB-modified nanoclay delayed the phase inversion process in a similar manner, showing a strong dependence on the CTAB concentration.

Gold nanorods–trypsin biocorona: a novel nano composite for in vitro cytotoxic activity towards MCF-7 and A-549 cancer cells

In the present work, we have synthesized cetyltrimethyl ammonium bromide (CTAB) capped gold nanorods (Au NRs) to evaluate apparent binding affinities for the adsorption of trypsin (TRP).