Trimethyl Ammonium Bromide Research Articles

Pencirian Genetik Pepper Yellow Leaf Curl Virus pada Tanaman Cabai Merah (Capsicum annuum) di Bengkulu

Chili is one of the horticultural commodities with increasing demand yearly. Rejang Lebong and Kepahiang regencies are the most significant chili-producing areas in Bengkulu. One of the crucial viruses in chili plants is Pepper yellow leaf curl virus (PYLCV). PYLCV virus infection in the vegetative phase can cause stunted plants and fail to bear fruit. This study aims to detect and genetically characterize PYLCV. Samples of chili plants were taken in these two districts using the purposive sampling method. Virus detection was carried out at the Genetics and Biotechnology Laboratory, Department of Biology. Extraction of viral DNA using the Cetyl Trimethyl Ammonium Bromide (CTAB) method. Rep and Trap gene amplification using universal primers of Bemovirus. SPG1 and SPG2. The PCR product was visualized on a 1.2% agarose gel in TAE.. Furthermore, the PCR products were sequenced in PT Genetics Science Indonesia. Virus gene sequences were aligned using Bioedit and MEGA X software. The results showed that of the 24 chili plants sampled in the study, 21 samples showed an amplicon with a size of ~ 900 bp, which follows the length of the amplicon based on the primer used. Of the 21 amplicon results, 6 of them were sequenced and genetically characterized. The results of the genetic characterization of the 6 samples showed the presence of 552 conservative sites (C) (75.6%), 178 variation sites (Vi) (24.4%), parsimony sites (Pi) (15.9%), and 70 singleton (S) sites (8.5%). The highest nucleotide base composition was thymine (T) with an average value of 30.1%, and the lowest was guanine (G) 21.9%, while the highest nucleotide combined composition was AT with an average value of 55%, the lowest was GC approximately 45%. The average genetic distance between samples was 0.13 (13%). Based on the phylogenetic tree, 6 samples were divided into two groups. Keywords: begomovirus, Bengkulu, Capsicum annuum

GO/ionic surfactant inspired photophysical modulation of rhodamine B in Reline with or without additives

Photophysical behaviour of rhodamine B (RB) in deep eutectic solvents (DES, formed by quaternary ammonium salt and hydrogen bond donor (HBD) in a specific eutectic ratio) with or without graphene oxide (GO) or ionic surfactants, is less known. The nature of Reline (choline chloride (ChCl): urea (HBD), 1:2), a well-known DES, has been designed by adding glycerol or water as the second HBD for sustained movement of RB. Effects of GO, surfactant, or GO + surfactant, in controlling RB movement, at various sites (GO surface, surfactant micelle, DES surface, or background solvent), have been fluorometrically reported. The basic nature of Reline (pH = 10.38) causes modification of GO surface (deprotonated site) and nature of RB (cationic → zwitter ionic). Above Reline-inspired changes have been found to modify interactions of RB with GO and/or sodium dodecyl sulphate (SDS, an anionic surfactant) or cetyl trimethyl ammonium bromide (CTAB, a cationic surfactant). SDS (10 mMdm−3, < critical micelle concentration (CMC) in Reline) shows ∼ 2.6, 1.6, and 1.4 fold fluorescence intensity enhancement of RB (in water, pure Reline, and methanol, respectively). However, GO and/or CTAB shows quenching behaviour. Further, the fluorescence of RB shows weak dependence on changing the second HBD (water or glycerol). DES-controlled cationic vs zwitterionic form of RB is responsible for the interaction and sustained movement towards GO surface, micellar surface, or negatively charged ion-pair formation (with SDS monomers). Findings of the work have implications in searching potential fluorescent levels/sensors for photophysics, photobiology, or wider vehicle means for sustained drug delivery.

Antiviral capacity of polypropylene/(1-Hexadecyl) trimethyl-ammonium bromide composites against COVID-19.

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, scientists from different areas are looking for alternatives to fight it. SARS-CoV-2, the cause of the infectious respiratory disease COVID-19, is mainly transmitted through direct or indirect contact with infected respiratory droplets. The integrity of the virus structure is crucial for its viability to attack human cells. Quaternary ammonium salts are characterized by having antiviral capabilities which alter or destroy the structure of the viral capsid. In this work, polypropylene (PP)/(1-Hexadecyl) trimethyl-ammonium bromide (CTAB) composites have been prepared in order to create an antiviral material. The composites were melt processed and blown to produce thin films. The CTAB content on the antiviral effect was evaluated using antibodies and serum from infected patients with the SARS-CoV-2 virus. In addition, the mechanical and thermal properties of blown films were investigated, and CTAB release kinetics from the films was followed by UV-Vis. The results indicate that the virus tends to remain less on the polymer surface by increasing the amount of CTAB in the PP matrix.

Investigation of chromate adsorption efficacy on organo-bentonite as potential in-situ adsorbent for groundwater remediation

As potential in-situ chromate adsorbents for groundwater remediation, two different organo-bentonites having two structurally different surfactants with the same carbon chain length (hexadecyl trimethyl ammonium bromide (HDTMAB) and benzyl dimethyl hexadecyl ammonium chloride (BDMHDAC)) were prepared. The Fourier transformed infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and N2 adsorption-desorption isotherm characterization results of the prepared organoclays reveal that the HDTMAB and BDMHDAC moieties are mainly located on the interlayer and outer surface as HDTMAB-Bt (H-Bt) and BDMHDAC-Bt (B-Bt), respectively. Based on the chromate adsorption efficacy in terms of the amount of surfactant in organoclay, 1.5 times the cation exchange capacity of Bt was selected for further studies. The two different organoclays prepared herein exhibited fast chromate adsorption within 60 min and equilibrated at 240 min at 10 and 100 mg/L of chromate solution concentration. Based on the Langmuir and Freundlich isotherm analyses, H-Bt fitted well to the Langmuir isotherm, and B-Bt followed the Freundlich isotherm model owing to differences in the locations of the modified surfactants. In-situ chromate adsorption utilizing flow-through experiments were performed successfully under simulated soil conditions. The prepared B-Bt exhibited high chromate adsorption efficacy of around 81% at the adsorbent concentration of 3 g/300 mL within 170 min. Therefore, organoclays prepared using natural clay materials can be used as potential in-situ chromate adsorbents for groundwater remediation.

Preparation and properties of modified nano-montmorillonite viscosity reducers

The nanometer sodium montmorillonite (Na-MMT), hexadecyl trimethyl ammonium bromide (CTAB), and octadecyl trimethyl sodium chloride (OTAC) were used as reaction monomers and ethanol as solvent, and two oil soluble viscosity reducers MMT-CTAB and MMT-OTAC were synthesized. Structural characterization experiment of modified montmorillonite were conducted by the infrared spectrometer, thermogravimetric analyzer, contact angle tester, scanning electron microscope, and dispersion observation. 20 wt% wax-containing model oil was chosen as the research object. The properties of two viscosity reducers on the pour point and viscosity of model oil were studied experimentally. The results showed that the two modified montmorillonite viscosity reducers were successfully prepared. And both can reduce the pour point and viscosity of model oil. The performance of MMT-OTAC was better than MMT-CTAB, which can reduce the pour point of model oil by 6 °C and the viscosity by 91.1%.

(Invited, Digital Presentation) Maximizing the Layered Structure and Interlayer Anion Exchange Characteristics of Nico-Based Layered Double Hydroxides for Battery-Type Supercapacitors

The transition metal-based layered double hydroxides (LDHs) have been extensively studied as promising electrode materials for battery-type supercapacitors owing to their excellent electrochemical activity and tunable chemical composition. In our work, we firstly built a novel three-dimensional composite with a core-shell structure by self-assembling NiCo-LDHs nanosheets on dual surface-modified halloysite nanotubes (D-HNTs) via in-situ electrodeposition and hydrothermal method (NiCo-LDH/D-HNTs). HNTs were pretreated by a dual surface modification for the first time including a carbonization process and cobalt doping to enhance electrical conductivity and chemical stability. This multicomponent hierarchical nanocomposite, NiCo-LDH/D-HNTs, has a specific capacity of 1401.4 C g-1 at 1 A g-1, a rate capability of 52.9% increasing the current density to 30 A g-1, and cycling stability of 80.8% after 2000 cycles. Moreover, using acetate anions (Ac-) as intercalating element, the NiCo-LDH nanosheets arraying on Ni Foam were prepared with the optimized amount of Ac- anions expanding the interlayer space of LDH nanosheets from 0.8 to 0.94 nm. An ultrahigh specific capacity of 1200 C g-1 at 1 A g-1 (690 C g-1 without Ac- anions), outstanding rate capability of 72.5% at 30 A g-1 and cycle stability of 79.90% after 4500 cycles were achieved. The enlarged interlayer spacing was beneficial for stabilizing the α-phase of LDH and accelerating the electron transport and electrolyte penetration in the electrochemical reaction. In addition, ionic surfactants like sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) were introduced to regulate the morphology of LDHs and alter the electrochemical performance. The original NiCo-LDHs shows microspheres formed by nanorods, and NiCo-LDHs-CTAB is similar, yet more tangled, while NiCo-LDHs-SDS is like microflowers consisting of interwoven nanosheets. NiCo-LDHs-SDS achieved better electrochemical performance (1003.6 C g-1 at 1 A g-1 and 73.84% after 3500 cycles) than NiCo-LDHs-CTAB (430.54 C g-1, 57.3%), and both higher than original NiCo-LDHs (278.5 C g-1, 54.3%), clearly showing the importance of morphology regulation in the synthesis of nanomaterials. Our work offers a promising strategy to synthesize functional nanomaterials with excellent electrochemical performance via integrating its unique layered structure and interlayer anion exchange characteristics.

Graphene/Waterborne Epoxy Coatings with Dual Functionalities of Barrier and Corrosion Inhibitor

A facile and environmentally-friendly method is developed to prepare graphene/waterborne epoxy (WEP) composite coatings. The graphene nanosheets are produced with electrochemical-exfoliation in the solution containing surfactants, cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The nanosheets containing solution thus formed is subjected to a quick dialysis and then directly used as a diluent for WEP without any further treatment. This preparation method overcomes the commonly identified problems of aggregations and ‘corrosion promotion’ effect associated with graphene, and increases the impedance of the composite coatings by more than two orders of magnitude. The analysis of anticorrosion performance suggested that the presence of surfactants not only improves the dispersibility of graphene nanosheets but also endows the composite coatings with both barrier and corrosion inhibition capabilities. The strategy reported herein may pave the path to the large-scale production of the graphene anticorrosion coatings. Figure 1

Catalytic ozonation mechanisms of Norfloxacin using Cu–CuFe2O4

As an easily recoverable, environmentally friendly and cost-effective catalyst, CuFe2O4 is a promising candidate for the catalytic ozonation of antibiotics in wastewater. However, its catalytic activity is restricted due to its limited active sites and low electron transfer efficiency. In this study, cetyl trimethyl ammonium bromide (CTAB) and Cu0 were doped with CuFe2O4 to introduce more OV, providing more active sites and improving electron transfer efficiency. Experimental results show that the optimum removal efficiency of the catalytic ozonation of Norfloxacin (NOR, a widely used antibiotic) using CTAB doped with Cu–CuFe2O4 as the catalyst is 81.58% with a first-order reaction kinetics constant of 0.03967 min-1. The associated O3 and catalyst dosages are 2.72 mg·L-1 and 0.1 g·L-1, respectively, which are 1.63 times and 2.22 times higher than those in an equivalent O3 system. OV can provide generation sites for surface hydroxyl groups and trigger ·O2− and 1O2 as the main active oxygen species. The synergistic redox cycles of Fe2+/Fe3+ and Cu0/Cu2+ accelerate electron transfer efficiency. The possible degradation pathways of NOR are identified as defluorination, naphthyridine ring-opening and piperazine ring-opening. In summary, this work proposes a new strategy for the modification of CuFe2O4 catalysts and provides new insights into the catalytic ozonation mechanisms for NOR removal.

An amphiphilic polymer as shale inhibitor in water-based drilling fluid

Shale hydration inhibitor in water-based drilling fluids (WBDFs) is the key to solve the problem of shale wellbore instability during drilling. In this study, a new amphoteric polymer was studied as a shale inhibitor. The amphiphilic copolymer ADL was synthesized by using acrylamide (AM), diallyl dimethyl ammonium chloride (DMDAAC) and dodecyl acrylate (LA) as monomers, benzoyl peroxide as initiator and hexadecyl trimethyl ammonium bromide (CTAB) as an emulsifier in aqueous solution. Infrared spectra indicated that the target product was synthesized successfully. TGA showed that the copolymers had good temperature resistance and the decomposition temperature was 240°C. The performance of ADL was evaluated by linear expansion experiment, rolling recovery rate experiment. The inhibition mechanism of the ADL was analyzed by particle size distribution experiment, zeta potential experiment and contact angle experiment. The experimental results show that ADL can adsorb on the surface of shale to change its wettability and increase the repulsive force between shale particles, thus inhibiting the hydration of shale. Because of its excellent shale inhibition performance, ADL has a potential application prospect as a shale inhibitor in WBDF.

Comparative interaction of an anionic dye, ponceau 4R with triple viz., anionic, non-ionic and cationic micellar systems: Spectral and conductometric analysis

In this work, the interaction of ponceau 4R dye (P4R) with triple viz., anionic, nonionic and cationic micellar systems has been studied. The three surfactants employed were nonionic pluronic L-64 (PL-64), anionic sodium dodecyl sulphate (SDS) and cationic cetyl trimethyl ammonium bromide (CTAB). All the three dye - surfactants systems were investigated through UV - visible spectroscopy, conductivity, FT-IR, pH effect and SEM studies. There was short and strong bonding between the dye and all the three types of micelles as observed from FT-IR studies. The conductivity studies displayed greater interaction with CTAB than with SDS. The free energy of micellization, ∆G was observed to be -16.07 kJ mol−1 for P4R+ CTAB and -13.83 kJ mol−1 for P4R + SDS, demonstrating greater spontaneity and stability of the former combination. This can be explained due to strong electrostatic attraction between negatively charged P4R dye and positively charged micelle of CTAB. Overall, the anionic ponceau 4R dye has been successfully incorporated into the nonionic, anionic and cationic micellar systems. This is probably the first report of interaction of a similarly charged dye and surfactant system.

Highly Zn2+-conductive and robust modified montmorillonite protective layer of electrodes toward high-performance rechargeable zinc-ion batteries

• A protective layer of electrodes with expanded and robust interlayer. • Protective layer is prepared from organic montmorillonite and ZnSO 4 /MnSO 4 solution. • Protective layer with low-cost, high ionic conductivity and Zn 2+ transfer number. • Alleviate Zn corrosion, MnO 2 dissolution, side-reaction and Zn dendrite generation. • Improved rate capability and cyclability of the battery with the protective layer. The corrosion, parasitic side-reaction and dendrite of Zn anode as well as the dissolution of MnO 2 cathode limit the commercial application of zinc-ion batteries (ZIBs). Herein, a novel coating layer on Zn anode and MnO 2 cathode of rechargeable ZIBs is rationally designed by mixing hexadecyl trimethyl ammonium bromide(CTAB)-pillared organic montmorillonite with ZnSO 4 /MnSO 4 solution (ZnOMMT). ZnOMMT can serve as the protective layer to alleviate Zn corrosion and MnO 2 dissolution while the unique interlayer structure of ZnOMMT can also offer a selective pathway for fast Zn 2+ transfer and uniform Zn 2+ diffusion to inhibit the side-reaction and Zn dendrite generation. Notably, by the powerful pillaring of CTAB cations, the expanded and robust nanoscale interlayer tunnels of ZnOMMT for Zn 2+ diffusion are constructed to guarantee outstanding ionic conductivity (6.52 mS cm −1 ), high Zn 2+ transference number ( t + =0.66) and outstanding cyclic stability during deep cycles. Therefore, ZIBs with ZnOMMT coating layer deliver a steady long-term reversible capacity (267 mAh g −1 until 300 cycles at 0.5 A g −1 , 205 mAh g −1 until 700 cycles at 1.0 A g −1 ). The rational design of CTAB-pillared montmorillonite protective layer brings a brand-new opportunity to the realization of high-performance rechargeable ZIBs. A novel protective layer of electrodes with outstanding ionic conductivity, high Zn 2+ transference number, low-cost, expanded and robust nanoscale interlayer is fabricated from CTAB-pillared organic montmorillonite and ZnSO 4 /MnSO 4 solution, and utilized to alleviate Zn corrosion, MnO 2 dissolution, side-reaction and Zn dendrite generation and thus improve cyclability and rate capability.

Variability of White Spot Syndrome Virus (WSSV) Envelope Protein VP28 from Diseased Shrimp (Litopenaeus vannamei) in Indonesia

White Spot Disease (WSD) is a viral disease affecting crustaceans. Caused by the White Spot Syndrome Virus (WSSV), this disease has caused significant mortality in commercially cultivated marine shrimp species with severe impacts on the shrimp farming industry and may be a threat to wild shrimp stocks. Thorough studies on the molecular biology of this pathogen are urgently needed to improve understanding of the virus at a molecular level, including variation in key viral protein (VP) components of the WSSV virion. This study aimed to isolate and characterize WSSV VP28 gene encoding envelope proteins from Indonesian Pacific white shrimp (Litopenaeus vannamei) isolates. Infected juvenile shrimp were collected from Pangkep, Barru, and Pinrang Districts in South Sulawesi, Indonesia. Genomic DNA was isolated from infected shrimp muscle tissue using a DTAB-CTAB (dodecyle trimethyl ammonium bromide-hexadecyl trimethyl ammonium bromide) DNA extraction procedure. The WSSV VP28 DNA sequences from Pangkep, Barru, and Pinrang isolates were 640-680 bp in length. Homology of Pangkep isolates with isolates from Barru and Pinrang was 97-99%. BLAST-N (Basic Local Alignment Search Tool-Nucleotide) analysis showed isolates from all three sites clustered with WSSV VP28 accessions from China, Indonesia, Japan, South Carolina and Vietnam. These results increase the geographic spread and host taxon coverage of WSSV VP28 sequence data for Indonesia.

Adsorption of Bismarck Brown R Dyes Using Mesoporous Silica MCM-48

The adsorption of Bismarck Brown R (BBR) dye has been conducted using mesoporous silica (MCM-48). We synthesized the adsorbent using Ludox HS-40 as a silica source and surfactants of Cetyl Trimethylammonium Bromide (CTAB) and Triton X-100. The characterization of MCM-48 was performed using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Various contact times were used to study the adsorption kinetics, and concentrations were used to study the adsorption isotherm. The optimum contact time of Bismarck Brown R dye was 120 minutes, and the adsorption followed a pseudo-second-order model. Based on the equation Langmuir and Freundlich adsorption isotherms, the adsorption capacity values of each are obtained 158.7301 mg g-1 and 4.3601 mg g-1. Our results showed that the material can be used as a new dye adsorbent.

ZrO2 aerogels as drugs delivery platforms: Synthesis, cytotoxicity, and diclofenac delivery

This work reports on the synthesis of ZrO2 aerogels by the epoxide-assisted sol-gel method using supercritical drying with CO2, and investigates the influence of HNO3 as a catalyst and cetyl trimethyl ammonium bromide (CTAB) surfactant on the structural, morphological, and textural properties of ZrO2 aerogels. The results indicate that the ZrO2 aerogel prepared without using a catalyst and CTAB surfactant (Zr–0H/0C) had a high surface area (SBET = 275.30 m2 g−1). On the other hand, the use of CTAB surfactant helped to maintain the characteristic 3D network of the aerogel and increase the specific surface area (SBET) by up to 43.40% (Zr-0.1C). The in vitro biocompatibility of the Zr–0H/0C and Zr-0.1C aerogels was evaluated by performing direct hemolysis testing and in vitro cytotoxicity testing using MTT and LDH assays. A murine NIH/3T3 fibroblast cell line was used for these experiments. These results indicate that the ZrO2 aerogels are non-hemolytic and non-cytotoxic. Drug-loading experiments were performed on both ZrO2 aerogels to investigate their drug loading capacity and efficiency using diclofenac sodium (DS) as a model drug. The Zr-0.1C aerogel exhibited the highest efficiency and loading capacity (36.13 and 17.59%, respectively). DS release in simulated bodily fluids (pH 3, 5, and 7) was investigated and the Zr-0.1C aerogel showed sustained release at pH 7.4. In contrast, negligible release was observed at pH 3.0. ZrO2 aerogels are potential biomaterials that can be used as platforms for drug loading and release.

CTAB assisted solvent-free mechanosynthesis of MAPbX3 nanocrystals: Stability, and photoresponse

In this study, we have used only multifunctional cetyl trimethylammonium bromide (CTAB) with a mechano-synthesis approach, which involves hand grinding to grow hybrid organic-inorganic metal halide perovskite, HPs, (MAPbX3, X ​= ​Br, I). Simplicity, swiftness, reproducibility, and harmony with green chemistry credentials make the mechano-synthesis process a preferable approach to the synthesis of HPs. We have prepared HPs using an equimolar amount of MAX and PbX2 with a mmol amount of CTAB. Steady-state photoluminescence, X-ray diffraction (XRD), and time correlate single-photon count (TCSPC) were performed to investigate the optical and structural features of mechanochemically produced perovskite. The thermogravimetric analysis informs about the thermal stability of the nanocrystals. X-ray diffraction analysis reveals that mechanochemically synthesized HPs show high crystallinity and phase purity with stability over a period of time. The photoinduced current response of the perovskite reveals an excellent increase in photoconductivity when exposed to light (with a 1 ​V bias). The device fabricated of perovskite witnessed the prompt photoresponse under light illumination and temporally-stable photocurrent over the multiple cycles of light irradiation. The synthesized materials are useful for photovoltaic applications because of their phase purity, low bandgap, nanoscale size, long-term stability, and easy-to-produce approach.

Morphology and CO2 adsorption performance of novel ionic liquid microcapsules containing [Bmim][PF6

To solve the contradiction between the high content of ionic liquid (IL) and fast diffusion of CO2 for immobilized IL, this study researched a strategy to optimize the morphology of IL microcapsules by designing different surfactants and methods for improving CO2 adsorption behavior. A series of new IL microcapsules with different morphology were prepared with the aid of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) as core material, and silica gel or polysulfone (PSF) as shell materials. Then, the characteristics of the microcapsules were assessed via FT-IR spectroscopy, thermogravimetry, morphology, pore structure and CO2/N2 sorption. The results indicated that the morphology and IL loading amount of the microcapsules are significantly affected by the preparation method, the surfactant and carrier material. The obtained samples were micron-scale or even the nanometer scale with good particle dispersibility, meanwhile, the samples prepared by chemical precipitation method with hexadecyl trimethyl ammonium bromide as surfactant has smaller size and more gullies on the surface than the samples prepared by sol-gel method with sodium lignosulfonate as surfactant. The microcapsules prepared by the chemical precipitation and sol-gel methods have about 50 wt%∼70 wt% IL content. While, the sample prepared by the solvent evaporation method displays relatively the lowest IL amount. Moreover, CO2 sorption performance and diffusion, CO2/N2 selectivity and CO2 sorption/desorption cycles of sorbents were further discussed in detail. IL microcapsules with better morphology and higher IL content display excellent CO2 diffusion and sorption selectivity.

Synthesis and application of treated activated carbon for cationic dye removal from modelled aqueous solution

Use of activated carbon (AC) prepared from rice husk and treated with anionic surfactant is investigated to eliminate cationic dye crystal violet (CV) using modelled dye solution. AC modified with anionic surfactant sodium lauryl sulfate (ACSLS) and other two surfactant namely sodium dodecyl sulfonate and hexadecyl trimethyl ammonium bromide were used for the analysis. Optimum ACSLS was analyzed and characterized using BET, XRD, SEM accompanied with XEDS, FTIR, HR-TEM and zeta potential, which confirms the sorption of CV onto ACSLS. Influence of pH, dose of adsorbent, concentration of initial dye, contact time, additive salts as well as actual water samples were investigated. Presence of NH4+, Ca2+, Mg2+, Na2+, Ca2+and K+cations in dye solution were having negligible (less than 4 %) influence on dye removal capacity. Study of mass transfer parameters revealed intra particle diffusion and film diffusion both played their part, whereas other kinetic studies has shown that experimental data fitted best with Pseudo 2nd order rate. Isotherm studies accompanied with error analysis revealed that Langmuir isotherm controls the adsorption equilibrium with highest capacity of CV adsorption with optimum operating conditions as pH = 6, temperature = 318 K, adsorbent dose = 100 mg/L and dye concentration = 30–60 mg/L. Study of thermodynamics and temperature analysishave shown that the sorption reaction was favourable and spontaneous with rise in temperature and endothermic in nature. Column studies are reported for varying rate of flow, depth of bed and dye concentrations along with analysis of column experimental data with various models like Yoon-Nelson, Thomas, Bohart-Adam and Clark model. Reusability (no. of cycles) of used adsorbent was studied using regeneration experiments. Analysis inferred that AC modified using surfactants can be a useful technique for enhanced adsorption capacity of dyes from aqueous solution andnot much work has been reported on use of anionic surfactant modified AC for dye removal process.

Highly sensitive electro-oxidative voltammetric determination of anthelmintic drug albendazole using porous graphitic carbon nitride sensor infused with cationic micellar solution

A sensitive and novel electrochemical senser, acetyl trimethylammonium bromide (CTAB)-immobilized nitrogen rich g-C3N4 nanosheet modified carbon paste electrode was developed, for the electrochemical investigation of the anthelmintic drug Albendazole (ABZ) using voltammetric tools like cyclic and square wave voltammetry. The results showed that the modified carbon paste electrode exhibited remarkable electro-catalytic action towards the electrochemical oxidation of ABZ in a phosphate buffer solution at pH 3 compared to bare carbon paste electrode. The electrode material was characterized by CV, scanning electron microscopy (SEM), atomic force microscope (AFM), and electrochemical impedance spectroscopy (EIS). A highly sensitive square wave voltammetric technique was developed for the determination of ABZ, at a trace level with great precision and accuracy, good limit of detection (LOD) 0.01 µM and limit of quantification (LOQ) of 0.036 µM, in the concentration range of 0.2–10 µM. This approach can be used in pharmaceutical formulations for clinical diagnosis, quality assurance, and drug screening. In addition, this technique is also implemented for the assessment of ABZ in water samples and biological samples like urine and blood plasma.

Molecular dynamics simulation of enhancing surfactant flooding performance by using SiO2 nanoparticles

In this study, four kinds of commonly used surfactants in oil fields, namely anionic surfactant sodium dodecyl sulfate (SDS), cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB), nonionic surfactant primary alcobol ethoxylate (AEO-9) and zwitterionic surfactant dodecyl dimethyl carboxyl betaine (BS-12), were used as the research objects. The oil–water interfacial behaviors at different concentrations were studied by molecular dynamics simulation. Then, silica (SiO2) nanoparticles were combined with surfactant to observe the influence of nanoparticles on the configuration of surfactant monolayer, and to explore the optimal conditions for the synergistic flooding scheme of these nanoparticles and surfactant. The thickness and density of the oil–water interface layer, the radial distribution function (RDF) between the surfactant head group and water molecules, the mean square displacement (MSD) of water molecules around the surfactant head group, the oil–water interfacial tension (IFT) and the surfactant interface formation energy (IFE) were investigated. Surfactant flooding performance of different types and the effect of nanoparticles on surfactants were discussed. The results show that the surfactant with different ionic types have the best concentration in reducing the oil–water interfacial tension, and the interfacial tension is significantly reduced to 7.33 mN/m after adding nano-SiO2 particles in BS-12. After kinetic equilibrium, SDS and CTAB are arranged in an approximately regular manner, non-polar groups are inserted into the oil phase, polar groups extend into the aqueous phase, the long-chain head groups of AEO-9 molecules spread and stack at the interface, and BS-12 is irregularly distributed and some molecules are immersed in the oil phase. After adding nano-SiO2 particles, SDS, BS-12 and nano-SiO2 particles can be observed mutually repulsive in the interface morphology, while CTAB, AEO-9 and nano-SiO2 particles exhibit mutual attraction.

An environmentally friendly material for red tide algae removal: Performance and mechanism

Red tide is a kind of marine disaster caused by the accumulation or proliferation of microalgae and other organisms in a short period of time, and utilizing modified clay to control and inhibit red tide is the preferred method. Among them, the application potential of organic-modified clay is high; unlike inorganic and microbial modifications, it has a broad-spectrum removal capacity on red tide algae at extremely low dosages. However, it has some disadvantages such as severe toxicity and high residual turbidity, leading to several limitations in its practical application. Therefore, it has become urgent to select organic-modified reagents with higher efficiency, weaker toxicity and lower residual turbidity. In this study, the typical red tide alga——Prorocentrum donghaiense was selected to detect the removal capacity of Polydimethyl diallyl ammonium chloride (PDMDAAC) modified clay (MP) by comparing with the Hexadecyl trimethyl ammonium bromide (HDTMA) modified clay (MH). Not only the physiological stress and flocculation effects of two modified clays on microalgae had been discussed, but also the properties of the modified clays had been characterized in this study. The results showed that the low degree of oxidative stress and less damage to the cell membrane make MP more environmentally friendly, PDMDAAC can remove microalgae at a low dose (2 mg/L) and quickly clarify the water by significantly enhancing the flocculation capacity of clay. In addition to discussing the removal mechanism of two modified clays on microalgae, schematic diagrams of the pathways were drafted. This study will provide support for the development of organic-modified clay.