The phase behaviour of cetyltrimethylammonium chloride surfactant aqueous solutions at high concentrations: An all-atom molecular dynamics simulation study

We explore the phase behaviour of aqueous solutions of the cetyltrimethyl ammonium chloride (CTAC) surfactant and in particular the transition from the micellar phase (L1) to the hexagonal columnar phase...

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.

Green Synthesis and Biological Study of Pyrimidone derivatives employing Cetyltrimethyl ammonium bromide under solvent free condition

In this study, we are reporting a solvent free Biginelli reaction using aromatic aldehydes, ethyl acetoacetate and urea in presence of cetyl tri-methyl ammonium bromide as a catalyst. The reaction is green and environmentally benign. The yield of three component condensation reaction is excellent. The products were screened for anti-bacterial and anti-fungal activity. The method is simple and convenient. The catalyst is novel and easily available, non-expensive and nontoxic.

Preparation of Barium-Hexaferrite/Gold Janus Nanoplatelets Using the Pickering Emulsion Method

Janus particles, which have two surfaces exhibiting different properties, are promising candidates for various applications. For example, magneto-optic Janus particles could be used for in-vivo cancer imaging, drug delivery, and photothermal therapy. The preparation of such materials on a relatively large scale is challenging, especially if the Janus structure consists of a hard magnetic material like barium hexaferrite nanoplatelets. The focus of this study was to adopt the known Pickering emulsion, i.e., Granick’s method, for the preparation of barium-hexaferrite/gold Janus nanoplatelets. The wax-in-water Pickering emulsions were stabilized with a combination of cetyltrimethyl ammonium bromide and barium hexaferrite nanoplatelets at 80 °C. Colloidosomes of solidified wax covered with the barium hexaferrite nanoplatelets formed after cooling the Pickering emulsions to room temperature. The formation and microstructure of the colloidosomes were thoroughly studied by optical and scanning electron microscopy. The process was optimized by various processing parameters, such as the composition of the emulsion system and the speed and time of emulsification. The colloidosomes with the highest surface coverage were used to prepare the Janus nanoplatelets by decorating the exposed surfaces of the barium hexaferrite nanoplatelets with gold nanospheres using mercaptan chemistry. Transmission electron microscopy was used to inspect the barium-hexaferrite/gold Janus nanoplatelets that were prepared for the first time.

The Effect of Halide Counter Ions and Methanol on the Foaming Behavior of Cationic Surfactants and a Mechanism Study

In this work, four quaternary ammonium cationic surfactants including cetyltrimethyl ammonium fluoride (CTAF), cetyltrimethyl ammonium chloride (CTAC), cetyltrimethyl ammonium bromide (CTAB) and cetyltrimethyl ammonium iodide (CTAI) were investigated to study the effect of halide anions on the surface activity and foaming performance. The result showed that CTAF had superior surface activity, which could reduce the surface tension of water to 33.15 mN/m at a low CMC (critical micelle formation concentration) of 1.65 mmol/L. Based on the calculation of Amin (the minimum occupied area per surfactant molecule), we assumed that this higher surface activity was related to the small ionic radius of the fluorine ion (F–). The foamability and foam stability of CTAF has great advantages over other surfactants studied. On this basis, the factors affecting the formation and stabilization of the CTAF foam were investigated. The results showed that foam formation benefited from high temperatures and low methanol concentration, while high salinity was beneficial for foam stability. When CTAF at a concentration of 0.2% was used as a foaming agent, foaming was excellent at a methanol concentration of 10%, a salinity of 22 ⨯ 104 mg/L, and a temperature of 90°C. With this study, uncertainties that existed in the literature regarding the effect of anion on surface activity and foam performance were explained and the effect of temperature, methanol and salinity on foam generation and stabilization was understood.

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.

Genome Analysis of Mungbean [Vigna radiata (L.) Wilczek] using Simple Sequence Repeats (SSR) Mapping Data

Background: Agricultural research chiefly focuses on the ways to increase productivity of staple food crops like wheat and rice, but still there are crops where research focus is meagre like nutritionally important mungbean crop grown by marginal farmers in crop rotation systems. Mungbean is leguminous crop which is high in protein content thus it offers health benefits at cheaper rates. The present work emphasizes on finding genetic diversity in mungbean germplasm on the basis of chemical and molecular analysis for micronutrients variation (iron and zinc). The identified molecular markers having linkage with high iron and zinc concentrations in the seeds can prove helpful in expansion of biofortification programme.Methods: Fifty-one green gram genotypes viz. varieties released from CCS Haryana Agricultural University (HAU), Hisar, Punjab Agricultural University (PAU), Ludhiana, Indian Institute of Pulse Research (IIPR), Kanpur and some advanced breeding lines were included in the study. Acid digested samples were used for determination of Fe and Zn by Atomic Absorption Spectrophotometer. Young seedlings leaves were used for isolation of genomic DNA using 2% CTAB (cetyltrimethyl ammonium bromide). Result: Total of fifty-one mungbean genotypes were tested using fifty simple sequence repeat (SSR) primers. Out of fifty primers screened, 16 primers generated 35 bands. Iron (Fe) and zinc (Zn) in mungbean lines was 36.90 to 107.1 mg/kg and 14.2 to 53.8 mg/kg respectively. The molecular studies based on SSR markers also indicates existence of ample genetic diversity at molecular level.