Cationic Surfactant Cetyltrimethylammonium Bromide Research Articles

Effects of ion doping on the dielectric and electro-optical properties of chiral nematic liquid crystal

This study presents experimental findings pertaining to the use of the cationic surfactant cetyltrimethylammonium bromide (CTAB) as a dopant dispersed in cholesteric liquid crystal. The impact of the additive on the electrical and dielectric properties was investigated by dielectric spectroscopy. Compared with that in the pure counterpart, the dielectric relaxation frequency increased due to the added ions in the cholesteric liquid crystals impregnated with 0.01–0.5- wt% CTAB. Furthermore, by analyzing the dielectric spectra in a specific frequency range, the DC conductivity, ion density, and diffusion coefficient were calculated and compared. By fitting the experimental data into the Arrhenius equation, the activation energy was obtained as well. Our experimental results illustrated that all these physical properties were strongly dependent on the CTAB concentration and the temperature. This work also involved the electro-optical measurement in combination with the observation of optical texture. The ion addition provoked electrohydrodynamic flows in a surfactant-dispersed mixture, generating a homogeneous and transparent uniform lying helix state between two low-transmission optical states—the focal conic and dynamic scattering states. The operating frequency range of the dynamic scattering state was significantly broadened by the ionic dopant.

Effect of TX-100 on solubilizing power of CTAB and CPC for H Acid: An experimental and computational analysis

The present research work investigates the solubility of an anionic dye 8-amino-1-naphthol-3,6-disulfonic acid (H Acid) within the micellar mediaof two cationic surfactants cetylpyridinium chloride (CPC) and cetyltrimethylammonium bromide (CTAB) as well as in the mixed micellar mediaof each cationic surfactant with Triton X-100 (TX-100). The data from differential absorption spectroscopy across a concentration range spanning from pre-micellar to post-micellar regions was used to determine the degree of solubilization by calculating the partition coefficient (Kx), binding constant (Kb) and Gibbs free energy associated with the relevant processes. Electrical conductivity of each cationic surfactant in the presence of H Acid was recorded in aqueous media and used to determine the CMC and subsequent thermodynamic parameters including entropy (ΔSm), enthalpy (ΔHm) and Gibbs free energy change (ΔGm) associated with the process of micellization. The computational analysis was carried out with GAUSSIAN 09 using a 6-311G + basis set with a DFT/ B3LYP hybrid approach and each set of energy minimization was executed to perform frequency calculations for Frontier molecular orbital analysis and to evaluate absorption spectra. Moreover, the molecular electrostatic potential surfaces (MESP) were also computed to find their suitable hydrophobic and hydrophilic interactions.

Novel surface modification strategies for enhanced CeO2 nanoparticle dispersion and suspension stability

This work aims to modify the surface characteristics of cerium oxide (ceria, CeO2) nanoparticles using different surface modification strategies for improved CeO2 nanoparticle dispersion and suspension stability. Analysis and discussion were conducted on the two surface modification processes used by a cationic surfactant like hexadecyl cetyltrimethylammonium bromide (CTAB) and a silane agent like tetraethyl orthosilicate (TEOS). Untreated CeO2 was used as reference material. The dispersion effect of surface-modified CeO2 nanoparticles at different pHs was determined by zeta potential measurements. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Particle size analysis (PSA), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Brunauer–Emmett–Teller analysis (BET), and X-ray diffraction (XRD) were used to confirm the efficacy of the surface modification of CeO2 nanoparticles. First, the results obtained in this experimental work demonstrate that both advanced modifications greatly enhance the dispersion and suspension stability of surface-modified CeO2 nanoparticles in comparison with untreated CeO2 nanoparticles. Second, it is also shown that the surface-modified CeO2 nanoparticles obtained through a silanization surface process with TEOS silane agent had a better dispersion effect and dispersion stability than the surface-modified CeO2 nanoparticles obtained by surface modification with CTAB cationic surfactant. These results can help better understand how advanced surface modifications can assist the application of well-dispersed CeO2 nanoparticles in technological applications.

Enhanced electrochemical properties of cobalt oxide nanoparticle electrode modified with low concentration of cationic surfactant

Metal oxides are proficient electrode materials for supercapacitors because of their physiochemical properties, especially their wide range of oxidation states that facilitate charge transfer in redox reactions and compatibility with electrolytes. Their performances can be further improved by adding surfactants, which also help with controlled synthesis, inhibit aggregation, and alter surface characteristics. The functional groups present in the surfactant molecule can undergo chemical bonding with the surface of the metal oxide, thereby modifying their surface chemistry and electronic characteristics. Recent research has focused on increasing the specific capacitance of cobalt oxide owing to its large surface area and size. The surfactants help to control the surface modification as a size-reducing agent and improve the electrochemical properties. Herein, A facile co-precipitation method is employed in synthesising cobalt oxide without cationic surfactant cetyltrimethylammonium bromide (CTAB) and with different concentrations of CTAB, followed by calcination. Herein, we compare the electrochemical properties with varying concentrations of surfactant-assisted Co3O4. The modified Co3O4 electrode with a low surfactant concentration (CO 1) exhibits a highly specific capacitance of 531F/g at 5 mV/s with a potential window of 0.7 V. The CO 1 electrode is suitable for supercapacitor devices with a specific capacitance of 296F/g at 0.8 A/g. Moreover, the asymmetric supercapacitor composed of CO1//AC demonstrated a remarkable energy density of 46.2 Wh/Kg and a robust power density of 800 W/kg. These results indicate that the hierarchical porous structure accelerates electron and ion movement, lowers charge transfer resistance, and improves hybrid electrode capacitive properties.

Comprehensive understanding of co-producing fermentable sugar, furfural, and xylo-oligosaccharides through the pretreatment with CTAB-based deep eutectic solvent containing Brønsted and Lewis acid

The deep eutectic solvents (DESs) with additional functionalities synthesized using the cationic surfactant cetyltrimethylammonium bromide (CTAB) have gained attention due to their remarkable enzymatic enhancement capability. By combining CTAB, lactic acid, and FeCl3, a DES containing both Brønsted and Lewis acids was synthesized and the pretreatment parameters were optimized using response surface methodology. The results demonstrated the selective and efficient delignification (83.2 %) and xylan removal (76.3 %) from canola straw by CTAB:LA:Fe3+, resulting in an increased saccharification efficiency of 81.8 %. Besides, abundant furfural (3.36 g/L) and xylo-oligosaccharides (3.41 g/L) were co-produced during pretreatment, providing comprehensive insights into the efficient co-production of fermentable sugars, furfural, and xylo-oligosaccharides. A thorough analysis of mass balance and energy flow was conducted to evaluate the entire process. Then, molecular dynamics (MD) simulations and quantum chemical calculations were performed on lignocellulosic biomass models and elucidate the interactions between the biomass and CTAB:LA:Fe3+ at the molecular level through the independent gradient model (IGM), thus explaining the high removal efficiency of hemicellulose and lignin. Furthermore, the physicochemical properties of the DESs were investigated, and molecular-level insights into the mechanism of CTAB:LA:Fe3+ pretreatment of lignocellulosic biomass were proposed in conjunction with biomass characterization such as FT-IR and CLSM, as well as MD simulations.

Effect of CTAB premicelle and micelle formation on Bromophenol Blue spectra

AbstractThe interactions between surfactants and dyes in aqueous solutions are essential for gaining insights into dyeing processes across various industries and for driving advancements in chemical research. This paper investigates the interaction between the anionic dye bromophenol blue (BPB) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) in aqueous solutions. It was observed that the absorbance value at the maximum absorption peak of BPB changes systematically with increasing CTAB concentration, revealing the critical premicelle concentration (cpc) and critical micelle concentration (cmc) of CTAB. Employing a micellization model and measuring the electric conductivity across different concentrations of CTAB, the micellization thermodynamic parameters of CTAB, both in the absence and presence of BPB, were determined. The findings indicate that the associative interaction between BPB and CTAB significantly influences the formation of CTAB micelles.

PH/Ion Dual-Responsive Emulsion Via a Cationic Surfactant and Positively Charged Magnesium Hydroxide Nanosheets.

Emulsions, formed by dispersing a liquid into another immiscible one by virtue of emulsifiers, have been widely applied in commercial applications like foods, pharmaceuticals, cosmetics, and personal care, which always confront environmental and/or toxic questions due to emulsifiers' high dosage. Recently, a study on Pickering emulsions points out a solution to stable emulsions based on the costabilizing effect of colloidal particles, which focused on surface-active particles cooperating with oppositely charged ionic surfactants. Costabilized emulsions adopting a charge-similar ionic surfactant and particles were less studied. In this article, a hexane-in-water emulsion was prepared in use of a cationic surfactant cetyltrimethylammonium bromide (CTAB) with positively charged magnesium hydroxide (MH) nanosheets at low concentrations (10-5 M and 10-2 wt %, respectively). The emulsion is stable due to the synergy by CTAB and MH nanosheets, which functions in virtue of the electric repulsion by similarly charged particles, the mechanical shielding by MH nanosheets, and restrained water drainage in lamellae between droplets due to the gelation of MH nanosheets. Moreover, the emulsion is doubly switchable within emulsification/demulsification via convenient pH or ion manipulation, a mechanism based on the breakdown and rebuilding of the costabilizing synergy. Such dual-responsive emulsions show high potential for the delicate control of drug delivery, release, and biphasic biocatalysis applications.

Derivatization-free CTAB-induced fluorescence sensing strategy for determination of daptomycin in environmental, pharmaceutical, and biological samples

A simple, economical, green, and sensitive spectrofluorimetric method was developed for the determination of the cyclic lipopeptide antibiotic daptomycin (DPT). The method is based on the sensitizing effect of the cationic surfactant cetyltrimethylammonium bromide (CTAB) on the weak fluorescent signal of DPT. After excitation at 373 nm, DPT-CTAB fluoresces at a maximum intensity of 458 nm. Under the optimized conditions, the method exhibits linearity over the concentration range of 0.50–10.0 μg/mL with a detection limit down to 0.11 μg/mL. The study revealed excellent selectivity towards DPT in the presence of the co-administered drugs. The proposed method was able to determine DPT in its commercial vials, and the results were comparable to those obtained by the reported method. The high sensitivity of the developed method allowed its estimation in water and biological fluids (spiked plasma and urine samples) with high % recoveries (95.89–105.99%). DPT was successfully determined in rat plasma after intra-peritoneal administration, and the method was applied for the calculation of its pharmacokinetic parameters (Cmax, t1/2, tmax, and AUC) in rat plasma. Comparison with the reported methods reveals many benefits of the proposed spectrofluorimetric method, such as greenness, simplicity, sensitivity, and reliability. Finally, different recent assessment tools confirmed the greenness and whiteness of the proposed method.

Multifaceted insights into the molecular interactions of tetraalkylammonium-based quaternary ammonium salts with cetyltrimethylammonium bromide: unraveling structural, thermodynamic, and antibacterial effects

Tetraalkylammonium-based quaternary ammonium ([R4N+][DHP−]; R = Ethyl, Propyl, Butyl) salts were synthesized and subjected to in-depth analysis using NMR, FTIR and TG analysis. Subsequent investigations involved examining their impact on the aggregation patterns of the cationic surfactant Cetyltrimethylammonium bromide (CTAB) through the use of conductometry, fluorescence measurements, and UV-Visible spectroscopy. To gain a deeper understanding of the colloidal behavior of CTAB, the critical micelle concentration (cmc) of the surfactant was determined, both in the absence and presence of the quaternary ammonium salts. The observed variations in cmc values were attributed to structural changes within the surfactant-water mixture, made by the presence of these additives. In addition, the investigations include thermodynamic analysis, with a focus on studying the dependence of the cmc on temperature. The resultant thermodynamic parameters were utilized to elucidate the contributions of [R4N+][DHP−], to the electrostatic and hydrophobic interactions involved in the formation of surfactant micellar aggregates. Furthermore, the study assessed the impact of [R4N+][DHP−], on the surfactant’s antibacterial activity by quantifying the zone of inhibition, against both gram-positive and gram-negative bacterial species.

Effectively enhancing red fluorescence strategy and bioimaging applications of carbon dots

Red-emitting carbon dots have attracted much attention because of their excellent fluorescence properties. It is of great significance to synthesize red-emitting carbon dots with high fluorescence quantum yield. Herein, by using citric acid and 1,8-diaminonaphthalene as precursors in N, N-dimethylformamide, novel carbon dots (NC-CDs) exhibiting red emission at 607 nm upon excitation at 514 nm were synthesized via a solvent-thermal approach. NC-CDs aggregated in lipid droplets of cells, and hemin quenched their fluorescence. Subsequently, cationic surfactants cetyltrimethylammonium bromide, anionic surfactants sodium dodecyl sulfate and nonionic surfactants were used to functionalize the NC-CDs. The results indicated that both ionic surfactants increased the fluorescence quantum yield and solubility of NC-CDs with extended fluorescence lifetime. This approach is applicable to a class of carbon dots that possess both carboxyl and amino groups. Additionally, these functionalized NC-CDs exhibited high recognition sensitivity towards ClO− and Cu2+ respectively except for hemin. This study provides a novel approach for the synthesis of highly red-emitting carbon dots, expanding their applications in the field of biological imaging and sensing. The findings hold significant implications for the real-time monitoring of hemin in lipid droplets. Additionally, this work offers a simple method to dramatic enhance their fluorescence quantum yield.

Effect of the cationic surfactant cetyltrimethylammonium bromide on the decomposition of ethylbenzene hydroperoxide

Effect of the cationic surfactant cetyltrimethylammonium bromide on the decomposition of ethylbenzene hydroperoxide

Spectroscopic insights for the enhanced partitioning and removal of Reactive Violet 5 by mixed micellar formulations under optimized conditions: An ionic-nonionic mechanistic approach

This study demonstrates MEUF (micellar enhanced ultrafiltration) as an effective method for the removal of Reactive Violet 5 (RV5) coming from the synthetic waste. MEUF technique is currently employed to decrease aqueous systems toxicity by employing cationic surfactants micellar media, specifically CPC (cetylpyridinium chloride) and CTAB (Cetyltrimethylammonium bromide). The study also examines the impact of nonionic surfactant on the addition of Triton X-100 (TX-100), on solubilizing capacity of the cationic surfactants. Our goal is to determine the optimal conditions for achieving maximum removal efficiency. RV5 partitioning constant, Kb as well as Gibbs energy of the partition ΔGp determines surfactant and dye molecules interaction. Dye molecules initially interact with ionic surfactants to form ion pairs. Subsequently, these ion pairs become incorporated into micelles and later on can subsequently be removed by MEUFThe maximum values of ΔGp (free energy of partition) were determined to be −42.30 kJmol−1 and −37.15 kJmol−1 using cationic surfactants, CPC and CTAB, respectively. Increase in pollutant size results in easy filtration. This study examines the impact of different factors, such as pH, transmembrane pressure, electrolyte (NaCl), surfactant concentration and revolutions per minute (RPM), on the removal of RV5 from an aqueous system. MEUF efficiency has been evaluated through the determination of permeate flux and rejection percentage values. It has been noticed that both surfactants had the potential to effectively encapsulate RV5. However, overall, the highest R% (rejection percentage) of 97.17% was attained.

A label-free 5CB-based aptasensor for highly selective optical detection of amoxicillin residue in freshwater samples

ABSTRACT A novel application of thermotropic liquid crystal (LC) 5CB in an optical aptasensor for the sensitive detection of amoxycillin (AMOX) antibiotic has been reported. In the studied system, the glass substrates were treated with dimethyloctadecyl [3–(trimethoxysilyl) propyl] ammonium chloride (DMOAP) and an aqueous solution of cationic surfactant cetyltrimethylammonium bromide (CTAB) was used to obtain a homeotropically aligned 5CB monolayer at the LC-aqueous interface resulting in a uniformly dark appearance. A highly specific amoxycillin aptamer (AMXA) was immobilised on the glass substrate as a target recognition probe for AMOX molecules. The specific binding of AMXA and AMOX molecules induces orientational changes in LC ordering resulting in a change in LC optical textures observed under a Polarized Optical Microscope (POM). A low limit of detection (LOD) of 10 nM for AMOX was obtained using this sensing system. Additionally, a high specificity for AMOX was also observed during comparative analysis. Finally, the developed biosensor was used to successfully detect AMOX in environments of potential application like tap water and lake water samples. Thus, the developed LC-based aptasensor can be a simple, sensitive and label‐free platform for monitoring real‐time levels of AMOX in freshwater environments.

Detection of chlorpyrifos via carbon nanotubes and AuPd nanoparticles-enhanced MXene electrode-based acetylcholinesterase biosensor

An ultra-sensitive and high-efficient acetylcholinesterase (AChE) electrochemical sensing platform on the basis of MXene/carbon nanotubes (CNTs) and Au-Pd composites was constructed for the rapid detection of chlorpyrifos. Negative CNTs modified with cationic surfactant cetyltrimethylammonium bromide were self-assembled on MXene through the electrostatic interaction. The introduction of CNTs and AuPd nanoparticles reduced the stacking of MXene layers and increased the utilization of specific surface area to load AChE. The MXene/CNTs/AuPd-based glassy carbon electrode (GCE) exhibited relatively lower electrochemical impedance compared with other materials. The prepared MXene/CNTs/AuPd-AChE/GCE-based electrochemical method possessed high repeatability, reproducibility, and anti-interference ability. The linear range for detecting chlorpyrifos was 2.85 × 10−12–2.85 × 10−6 M and the limit of detection was 1.98 pM. Finally, the established method was successfully used to detect chlorpyrifos in spinach and orange and recoveries were ranging from 93.68 % to 104.21 %, which presented the great potential for quantitatively analyzing of organophosphorus pesticides in food samples.

Surfactant mediated modulation of photophysics and self-assembly process of a small, substituted phenol

5-(tert-Butyl)-2-hydroxy-1,3- isophthalaldehyde (5-tBHI) exhibits a large Stokes shifted emission spectrum, irrespective of excitation wavelength in aqueous solution and thus can be useful in bio-imaging. It is imperative to understand the binding of 5-tBHI in micelles as micelle represent the simplest mimic of biological membrane. Hence, the interaction of 5-tBHI with cationic surfactant cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecyl sulfate (SDS), and neutral surfactant Triton X-100 (TX-100) was investigated. This help us elucidate the interplay of hydrophobicity and pH to modulate the ground and excited state intra/inter-molecular proton transfer processes of the probe. The absorption and fluorescence spectra of 5-tBHI have been found to be highly sensitive towards hydrophobicity and electrostatic interactions. However, no particular trend was observed, suggesting an incomplete encapsulation of the probe in the micelles. The observation from the steady state spectra could not be rationalized completely based on the time resolved fluorescence decays in the nanosecond-picosecond regime, suggesting that the processes are ultrafast in nature. Subsequently, analyses of fluorescent transients in femtosecond-picosecond regime provided a better explanation to match well with the steady state phenomena. It was found that pH has a dominant role to guide the direction of the two-state keto-enol tautomerisation. However, the effect of hydrophobicity can not be neglected as it pushes the equilibrium to the enol form. Furthermore, Fluorescence Lifetime Imaging Microscopy (FLIM), supported by SEM images, provide a pictorial idea of how the aggregation of the probe in neat water is affected by the nature of the surfactants. It further shows that SDS, with an acidic local pH favours the aggregation process, over CTAB and TX-100.

Effect of inorganic salts in coal seams on the sand-carrying capacity of hydroxypropyl guar foam-fracturing fluid: An experimental study

Coal seam water typically contains inorganic salts, which could affect the sand-carrying capacity of foam-fracturing fluid. This study selected the standard cationic surfactant cetyltrimethylammonium bromide as the foaming agent, used the high molecular polymer hydroxypropyl guar gum as the foam stabilizer to prepare foam-fracturing fluid, and selected silica particles as the proppant. The effects of different CaCl2, NaHCO3, MgSO4, and KCl concentrations on sand-carrying sedimentation of foam-fracturing fluid were evaluated. The effects of inorganic salts on foam morphology and foam morphology on proppant sedimentation were obtained through microscope observation, and the mechanism of inorganic salts on proppant sedimentation in foam-fracturing fluids was explored. The results show that 1% CaCl2 and 0.1% NaHCO3 inhibited the sand-carrying capacity of the foam-fracturing fluid, whereas two concentrations of MgSO4 and KCl promote the sand-carrying capacity of the foam-fracturing fluid. The effect of inorganic salts on the sand-carrying properties of cationic surfactant foam-fracturing fluids is divided into two main stages. During the settling phase, inorganic salts affect settling by changing the viscosity of the foam-fracturing fluid and the repulsive force of the double electric layer on the proppant. During the suspension phase, the proppant improves the probability of collision between the proppant and the foam by promoting the foam particle size and improves the hindering effect of foam pressure and structural forces on the proppant. The results have a guiding significance for developing foam-fracturing technology.

Effect of Substituents on Solubility, Medicinal, Absorption, Emission and Cationic/Anionic Detection Properties of Anthraquinone Derivatives.

Anthraquinones constitute an important class of compounds with wide applications. The solubility of derivatives at 298.15K was discussed in ethanol-water solution and at atmospheric pressure, the solubility of 1-amino-4-hydroxy-9,10-anthraquinone (AHAQ) in binary solvents (ethanol-water combinations) was determined. Colour strength and fastening properties depend upon the kind and position of a hydrophobic group connected to the phenoxy ring of Anthraquinone moiety. There is a continuing interest in the creation of novel anthraquinone derivatives with biological activities since they have demonstrated potential for treating multiple sclerosis. For this purpose, by utilizing voltammetric and absorption studies, interactions of various derivatives with calf thymus DNA (ct-DNA) and the cationic surfactant cetyltrimethylammoniumbromide (CTAB) were examined. Here prominent Hydrophobic interaction and electron transfer resulting in binding to CTAB micelles were observed. The polarity index of the media was assessed and associated with the electrochemical parameters. The medicinal behaviour of Anthraquinone derivatives was a result of electron transfer reactions with DNA. UV-Visible and fluorescence properties were due to the transitions between n* and π* orbitals. Large absorption band with low dichroic ratio was characteristic of various derivatives of Anthraquinone. Presence of -NH group proves various derivatives remarkable calorimetric and anionic sensors.

Investigation of surfactant effect on ozone bubble motion and mass transfer characteristics

The low solubility and low mass transfer efficiency of ozone (O3) in water are important reasons for limiting the application of ozone oxidation technology and advanced ozone oxidation technology. Low-dose surfactants were introduced to affect the behavior of ozone bubbles, influencing the ozone mass transfer efficiency. The motion of ozone bubbles in three different types of surfactant solutions (polyoxyethylene lauryl ether (Brij35), sodium dodecylsulfate (SDS), and cetyltrimethylammonium bromide (CTAB)) was observed. The decrease in surface tension led to a decrease in bubble size, a tendency to spherical shape, an increase in gas content and residence time, a decrease in lateral displacement of a single bubble, and a more stable trajectory. The effect of surfactants on ozone mass transfer was further investigated. The addition of surfactant was found to increase the gas-liquid interface area but decrease the liquid phase mass transfer coefficient, and the extent of the two opposite effects varied for different surfactants. The analysis combined with the removal of pollutant p-Nitrophenol (PNP) showed that the addition of the nonionic surfactant Brij35 and the anionic surfactant SDS inhibited ozone mass transfer, while low concentrations of the cationic surfactant CTAB enhanced ozone mass transfer. When the CTAB concentration was 3 mg L−1, the ozone volume mass transfer coefficient reached a maximum of 0.2902 min−1.

Enabling high rate capability and stability all-solid-state batteries via cationic surfactant modification of composite electrolyte

The garnet-type solid electrolyte Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was modified with a cationic surfactant Cetyltrimethylammonium Bromide (CTAB) to improve the dispersion of LLZTO inorganic particles in Poly (ethylene oxide) (PEO) electrolyte (PEO-LLZTO@CTAB) by a liquid phase casting method. During fabrication, the cationic modifier CTAB is uniformly adsorbed on the surface of LLZTO particles, which can effectively reduce their surface energy and lead to a thin CTAB surface coating layer. This fabricated PEO-LLZTO@CTAB can avoid the aggregation of LLZTO particles in the composite solid-state electrolyte (CSSE) and improve the interfacial contact at the PEO/LLZTO interface, thus reducing the overall resistance of PEO-LLZTO@CTAB/Li half-cell and inhibiting the dendrite growth during cycling. The all-solid-state batteries (ASSBs) with LiFePO4 (LFP) as the cathode, PEO-LLZTO@CTAB as the electrolyte and Li as the anode exhibit a high initial discharge capacity of 146.6 mAh-g−1, excellent rate performance and high-capacity retention of 91.0 % after 300 cycles at 0.2 C multiplier and 60 °C within the voltage range of 2.7–4.0 V.

Cetyltrimethylammonium bromide reformed ceria nanocomposites of chemical mechanical planarization for silica wafers

BackgroundChemical-mechanical planarization (CMP) is the most important process in the semiconductor industry, as it affects the product manufacturing yield. Of the several factors involved in planarization, the choice of abrasive slurries affects the extent to which impurities and roughness are removed. Cerium oxide (CeO2) is considered an outstanding polishing material because of its excellent hardness, well-controlled structure, and chemical force, and CMP requires well-dispersed slurry nanoparticles (NPs) with uniform structure, size, and shape. In this study, urea/alkaline-induced nanocubic MethodsCeO2 was synthesized in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB)-generated cubic CeO2 NPs, which were then used in a silica wafer polishing test. Dynamic laser scattering and transmission electron microscopy indicated that the cubic plate NP size distribution and zeta potential ranged from 18 to 30 nm when measured between –35 and –45 mV. Elemental composition via X-ray photoelectron spectroscopy was studied to demonstrate the mechanism of Ce3+/Ce4+ with crystal information, which matched the X-ray diffraction grain size calculation and finite element–scanning electron microscopy measurements. We also performed a simulation of cubic CeO2 NP formation and pillar CeO2 inhibition under an additional amount of structure-modifying agent (e.g., CTAB). Fourier transform infrared spectra indicated a successful CTAB reaction with CeO2. Small angle X-ray scattering spectra were used to obtain simulated NP shapes and parameters via the SasView model. A confocal laser scanning microscope was then used to measure the roughness and 2-D plane view of an 8-inch tetraethyl orthosilicate coated silica wafer. Significant findingsOur results showed that the bared silica wafer planarize with CTABx-CeO2 NPs reduced the ISO grade number from Level 9 to Level 7, which corresponds to a 70.7–74.5% roughness planarization of the raw material. This study presents a fast, uniform, low-roughness CMP slurry material synthesis and characterization method that can enhance the technique of slurry nanoparticle synthesis from stable materials.