Cetyltrimethylammonium Bromide Concentration Research Articles

Liquid crystals purity assay using nonaqueous capillary electrokinetic chromatography.

A method for purity control of newly synthesized lactic acid-based liquid crystals has been developed. The electrokinetic chromatography proved to be suitable for the separation of these electroneutral substances from their impurities. The separations were performed in an acidic acetonitrile-based background electrolyte (BGE) with a pseudostationary phase formed by a cationic surfactant. During the optimization step, appropriate concentrations of cetyltrimethylammonium bromide, acetic acid, and water were seeked. In the optimized method, separations were carried out in acetonitrile with 1-mol/L acetic acid, 80-mmol/L cetyltrimethylammonium bromide, and 6% (v/v) water. Interesting positive effects of a small water content in the BGE on electroosmotic flow and resolution of liquid crystal substances from their impurities were observed and discussed. Samples of five liquid crystal substances, both pure and containing impurities from synthesis, were analyzed. The identification of analytes was based on a comparison of relative migration times related to the migration time of mesityl oxide. For all five samples, impurities were separated from the liquid crystals and the method thus showed its viability. To the best of our knowledge, this method is used for the first time for the purity control of newly synthesized liquid crystals. This method can be used to confirm or complement the results obtained by commonly used high-performance liquid chromatography and supercritical fluid chromatography methods. Furthermore, the electrokinetic chromatography method requires very small amounts of sample, solvents, and buffer constituents. Overall, its operational costs are significantly lower.

Control Of Particle Adhesion On InGaAs Surface In Basic Solution By The Addition Of Cationic Surfactant

The adhesion of silica particles on an InGaAs surface in a 1/1/100 NH4OH–H2O2–H2O mixture (APM) solution was investigated. To control the particle adhesion on InGaAs surface, hexadecyltrimethylammonium bromide (CTAB) was added to the APM solution at concentrations of 10-4–10-2 M, and its effect was examined. To understand the adhesion behavior of silica particles on the InGaAs surface in the APM solution with the addition of CTAB, Lifshitz–van der Waals energy, acid–base interaction energy, and electrostatic energy were estimated. In addition, energy barrier was calculated from the changes in those energies. It was found that the behavior of the energy barrier was strongly related to the adhesion behavior of the silica particles on the InGaAs in the APM solution with different concentrations of CTAB. Therefore, the addition of CTAB changes the interaction force and the energy for particle to adhere to the InGaAs surface.

Micro-structured and self-assembled patterns in PLA-cast films as a function of CTAB content, magnesium and substratum hydrophobicity

The fabrication of biomaterials with structured surfaces for medical purposes is a topic of great interest. Producing topographies with certain characteristics can benefit tissue formation and/or reduce the probability of developing an infection due to the hindrance shown by certain micro-structures to microbial adhesion.This work presents a new, economically attractive way to fabricate micro-structured patterns on the surface of one of the currently most interesting bioabsorbable polymeric materials, polylactic acid (PLA). Formation of homogeneously distributed holes is presented as a function of three factors: the concentration of cetyltrimethylammonium bromide (CTAB), the presence or not of the dispersant magnesium, and the hydrophobicity of the support used in the PLA-film fabrication, silicone or glass. The size of the holes increases with the CTAB concentration: from 1 to 5 µm on silicone and 2 to 20 µm on glass. Magnesium particles make CTAB to disperse better inside the PLA matrix, provoking the irregular holes observed on glass become regular with sizes between 0.5 and 2 µm. The topographies obtained on silicone are highly stable over time, while on glass they degrade after 28 days. Consequently, it is possible to design a wide spectrum of micro-structured topographies, covering both antimicrobial and tissue integration targets.

Sabatier Principle for Rationalizing Enzymatic Hydrolysis of a Synthetic Polyester.

Interfacial enzyme reactions are common in Nature and in industrial settings, including the enzymatic deconstruction of poly(ethylene terephthalate) (PET) waste. Kinetic descriptions of PET hydrolases are necessary for both comparative analyses, discussions of structure–function relations and rational optimization of technical processes. We investigated whether the Sabatier principle could be used for this purpose. Specifically, we compared the kinetics of two well-known PET hydrolases, leaf-branch compost cutinase (LCC) and a cutinase from the bacterium Thermobifida fusca (TfC), when adding different concentrations of the surfactant cetyltrimethylammonium bromide (CTAB). We found that CTAB consistently lowered the strength of enzyme–PET interactions, while its effect on enzymatic turnover was strongly biphasic. Thus, at gradually increasing CTAB concentrations, turnover was initially promoted and subsequently suppressed. This correlation with maximal turnover at an intermediate binding strength was in accordance with the Sabatier principle. One consequence of these results was that both enzymes had too strong intrinsic interaction with PET for optimal turnover, especially TfC, which showed a 20-fold improvement of kcat at the maximum. LCC on the other hand had an intrinsic substrate affinity closer to the Sabatier optimum, and the turnover rate was 5-fold improved at weakened substrate binding. Our results showed that the Sabatier principle may indeed rationalize enzymatic PET degradation and support process optimization. Finally, we suggest that future discovery efforts should consider enzymes with weakened substrate binding because strong adsorption seems to limit their catalytic performance.

Colorimetric detection of poly(methyl methacrylate) using polydiacetylene/zinc(II)/zinc oxide nanocomposites

This study introduces a facile approach for fabricating colorimetric sensors that differentiate concentration and molecular weight of poly(methyl methacrylate) (PMMA). A cationic surfactant, cetyltrimethylammonium bromide (CTAB), is incorporated into the structure of polydiacetylene(PDA)/Zn2+/ZnO nanocomposites via a simple mixing process. The interaction between PMMA carbonyl group and CTAB headgroup is the key mechanism inducing color transition of the nanocomposites. The sensitivity can be tuned by adjusting experimental parameters including CTAB concentration, photopolymerization time, and PDA alkyl chain length. Solid-state sensors are fabricated by embedding into filter papers. Our finding extends the utilization of PDA-based materials in polymer sensing applications.

Electrode material for high performance symmetric supercapacitors based on superparamagnetic Fe3O4 nanoparticles modified with cetyltrimetylammonium bromide

A facile preparation method is reported to develop a supercapacitance material with high specific capacitance and stability. Fe3O4 superparamagnetic material was synthesised via CTAB assisted co-precipitation method to modify the morphology. Presence of CTAB has resulted in excellent output in terms of high specific capacitance of 1192 F/g at a current density of 1 A/g. 93% of charge storage capacity was retained by the working electrode after 4000 charge-discharge cycles with the optimum concentration of CTAB. The TEM micrograph showed a quasi-spherical morphology for the bare Fe3O4 and the same was modified to semi-cuboidal shape after CTAB modification. The change in crystal lattice was confirmed through SAED in parallel to the WAXRD analysis. The phase purity was deciphered using XPS and surface roughness of the electrode was studied using AFM. Increased saturation magnetisation value for CTAB modified Fe3O4 was also in line with the improved charge storage capacity.

Interactions between amino acids and a cationic surfactant in binary solvent system

The interaction of the cationic surfactant cetyltrimethylammonium bromide (CTAB) with amino acids (Lysine and Serine) in water and binary solvent combinations (Water-Ethyl Acetate) was studied conductometrically in this work. Solution formation method was used to study the effect of different parameters on interactions. Measured specific data were used to calculate the effect of temperature and concentration of added amino acids on the micellization of surfactant. Thermodynamic parameters for micellization i.e., Gibb's energy (ΔGm), and enthalpy (ΔHm), and entropy (ΔSm) have also been determined in presence of amino acids (Serine and Lysine). Results revealed that an increase in the concentration of added amino acids and binary solvent mixture (Ethyl Acetate-Water) causes an increase in critical micelle concentration (CMC) of CTAB where CMC of CTAB decreases with increasing temperature due to a decrease in hydrophobicity of molecules.

Molecular Dynamics Studies on Effective Surface-Active Additives: Toward Hard Water-Resistant Chemical Flooding for Enhanced Oil Recovery.

Divalent ions, which are omnipresent in brine, may be detrimental to surfactant functionalities during chemical flooding in the enhanced oil recovery (EOR) process. Surfactant blending is one potential solution to overcome such an adverse effect. Herein, we report a molecular dynamics (MD) study to investigate the molecular arrangement and possible applications of surfactant blending in hard water-resistant chemical flooding for oil recovery. We chose commonly used anionic surfactants, sodium dodecyl sulfate (SDS), as primary surfactants. The non-ionic (propanol) and cationic [cetrimonium bromide (CTAB)] surfactants with a wide range of concentrations are introduced to the primary system. We demonstrate that CTAB can disaggregate the cation bridging when their concentration is above a certain threshold. This threshold value is related to the surfactant and cosurfactant surface charge in the interface region. The cation bridging density is maintained at a low level when the sum of surfactants and cosurfactant interface charges is neutral or positive. On the other hand, propanol barely disaggregates the cation bridging. When propanol concentration is above a certain value, it even facilitates the cation bridging formation. Both propanol and CTAB can further decrease the oil-brine interfacial tension (IFT) while having different efficacies (IFT decrement rate is different as their interface concentration increases). More rapid IFT decrement is observed when cation bridging is disaggregated (i.e., in systems with high CTAB concentrations). Increasing propanol concentration barely affects hydrogen bond (H-bond) formation between SDS and H2O because of a low propanol distribution around SDS. On the other hand, the first increasing and then decreasing trend in H-bond density between SDS and H2O is observed as CTAB concentration increases. Our work should provide important insights into designing chemical formulas in chemical flooding applications.

First electrochemical study of a potent antifungal drug caspofungin: Application to its enhanced voltammetric sensing based on the performance of boron-doped diamond electrode in CTAB-mediated measurements

This present study describes the first electrochemical investigation of caspofungin, which is a semisynthetic echinocandin class of antifungal drug. For this purpose, an electrochemically pretreated (anodically and subsequently cathodically) boron-doped diamond (BDD) electrode was used. The cyclic voltammetric scans showed a single oxidation step that is irreversible and controlled by a dual mechanism of adsorption and diffusion. For the optimization of experimental conditions, the influence of the electrode pretreatment, pH of the supporting electrolyte, concentration of cationic surfactant cetyltrimethylammonium bromide (CTAB), accumulation variables, and instrumental parameters was examined on the current response of caspofungin. The improved sensitivity of the voltammetric measurements was observed due to the synergistic effect of CTAB on the adsorption capacity of BDD electrode in alkaline pH conditions. Employing square-wave adsorptive stripping voltammetry (using open-circuit accumulation for 60 s), the oxidation signal at around +0.45 V allowed to the determination of caspofungin in Britton-Robinson buffer at pH 11.0 containing 1 × 10−4 M CTAB. The process could be used in the concentration range from 2.06 × 10−7 to 1.03 × 10−5 M (from 0.25 to 12.5 μg mL−1 as acetate salt) with a detection limit of 5.27 × 10−8 M (0.064 μg mL−1 as acetate salt). A technique developed here was used successfully to determine caspofungin concentration in commercial parenteral dosage formulations.

Synthesis of Porous Hollow Organosilica Particles with Tunable Shell Thickness.

Porous hollow silica particles possess promising applications in many fields, ranging from drug delivery to catalysis. From the synthesis perspective, the most challenging parameters are the monodispersity of the size distribution and the thickness and porosity of the shell of the particles. This paper demonstrates a facile two-pot approach to prepare monodisperse porous-hollow silica particles with uniform spherical shape and well-tuned shell thickness. In this method, a series of porous-hollow inorganic and organic-inorganic core-shell silica particles were synthesized via hydrolysis and condensation of 1,2-bis(triethoxysilyl) ethane (BTEE) and tetraethyl orthosilicate (TEOS) in the presence of hexadecyltrimethylammonium bromide (CTAB) as a structure-directing agent on solid silica spheres as core templates. Finally, the core templates were removed via hydrothermal treatment under alkaline conditions. Transmission electron microscopy (TEM) was used to characterize the particles′ morphology and size distribution, while the changes in the chemical composition during synthesis were followed by Fourier-transform infrared spectroscopy. Single-particle inductively coupled plasma mass spectrometry (spICP-MS) was applied to assess the monodispersity of the hollow particles prepared with different reaction parameters. We found that the presence of BTEE is key to obtaining a well-defined shell structure, and the increase in the concentration of the precursor and the surfactant increases the thickness of the shell. TEM and spICP-MS measurements revealed that fused particles are also formed under suboptimal reaction parameters, causing the broadening of the size distribution, which can be preceded by using appropriate concentrations of BTEE, CTAB, and ammonia.

Facile synthesis of Fe3O4/Sio2/Cu nanoparticles: investigation of physicochemical attributes of interaction in cationic micellar media and photo-antibacterial impact

Solubilization of core-shell magnetic nanoparticles has gained new popularity as a versatile partitioning method with the recent growth in nanotechnology and related biotechnology applications. In this sense, Fe3O4/SiO2/Cu nanoparticles (NPs) were designed and characterized by various techniques such as Ultra-violet visible (UV-vis), Fourier transforms infrared (FTIR), X-ray diffractometry (XRD), scanning and transmission electron microscopy (SEM & TEM), energy dispersive X-ray (EDX) and thermogravimetric (TGA) analyses. The size determined by TEM analysis of Fe3O4/SiO2/Cu NPs was found in the range of 24 nm. The diffractometer results verified the impurity-free synthesis of the desired nanoparticles. Micellar solubilization and thermodynamics of micellization were determined correspondingly using a UV-Vis spectrophotometer and conductometer. The thermodynamics of micellization in terms of enthalpy, entropy and standard Gibb’s free energy was determined using electrical conductometry. The solubilization parameters viz. partition constant (Kc), binding constant (Kb), partition coefficient (Kx), and the corresponding Gibb’s free energies were estimated from the absorption spectroscopic analysis. The experimental outcomes and their computation revealed the rise in the critical micelle concentration of CTAB due to the incorporation of the nanoparticles with the micelles. Moreover, the photo-antibacterial activity of the nanoparticles in the bacteria culture environment showed effectiveness in comparison to the control group.

Synergistic adsorption and degradation of diclofenac by zero-valent iron modified spent bleaching earth carbon: Mechanism and toxicity assessment

Diclofenac (DCF) is a drug compound that exists widely in water bodies, which may pose a threat to the ecological environment. In this study, spent bleaching earth (SBE) was pyrolyzed, modified with cetyltrimethylammonium bromide (CTAB) and loaded with zero-valent iron (nZVI) to obtain CTAB-SBE@C-nZVI. The effects of CTAB concentration, Fe0 loading, CTAB-SBE@C-nZVI dosage, and initial pH value on the removal efficiency of DCF were studied. The results showed that the DCF removal efficiency could reach a maximum of 87.0% with 2.0 g/L dosage of the optimal material, which was prepared under the conditions of 30 mmol/L CTAB concentration, 25% Fe0 loading, and initial pH 5. It indicated that the strong adsorption of the material and the reduction effect of nZVI can achieve high-efficiency removal of DCF. Based on the detected reaction intermediate products, four possible degradation paths were inferred. The toxicity assessment of DCF and its intermediates manifested that the degradation of DCF by CTAB-SBE@C-nZVI was a process of gradual dechlorination and toxicity reduction. CTAB-SBE@C-nZVI displayed excellent DCF removal efficiency, good stability and environmental friendliness, achieving wastes treat wastes and exhibiting good prospects.

Spectrophotometric and conductometric studies on the interaction of surfactant with polyelectrolyte in the presence of dye in aqueous medium

The concentration of methyl red (MR) dye has a significant influence on how the CTAB + NaPSS complex (CTAPSS) aggregates and sticks together. However, the effect of MR dye on CTAPSS has not yet been thoroughly investigated. The major goal of this work is to use conductometry and UV–Vis. techniques to investigate the influence of MR on the interactions between a cationic surfactant, cetyltrimethylammonium bromide (CTAB) and an anionic polyelectrolyte, sodium polystyrene sulfonate (NaPSS) in aqueous environments. By observing changes in the dye's spectra and the breaking points of conductometric curves, it is obvious that MR causes the development of surfactant aggregates. Critical aggregation concentration (CAC), apparent critical micelle concentration (CMC*), ionization degree (α), binding constant, and various other important thermodynamic parameters were determined by conductivity techniques at 298.15 ± 0.2 K. The CAC and CMC* values dropped on raising the concentration of CTAB with MR in the CTAB + NaPSS + MR system, which is caused by the substantial electrostatic interactions between CTAB/NaPSS and MR. With anionic MR, aggregation and micellization become easier, as seen by hypsochromic shift and reduction in the absorption band's intensity. With increasing CTAB concentrations, the absorption spectra of MR were observed between 430 and 440 nm for the basic form steadily dropped to 414–421 nm. The Benesi-Hildebrand equation was used to calculate the binding constants from the absorption spectra of MR. The CMC of CTAB in water was determined to be 0.00091 molL-1 but the CMC* of CTAB for the CTAB + NaPSS system was determined to be 0.001438 molL-1 and CMC* for the CTAB + NaPSS + MR system was observed to be 0.001328 molL-1 by conductivity and 0.001310 molL-1 by UV–Vis. spectroscopy at 298.15 ± 0.2 K. Also, it is observed that CMC* obtained by spectroscopy is slightly lower (0.001310 mol L-1) than those obtained from conductometry (0.001328 mol L-1) since the spectrum is extremely sensitive for molecular interactions and their properties.

Synthesis of two-dimensional WS2/nickel nanocomposites via electroforming for high-performance micro/nano mould tools

To reduce the adhesion and friction between polymer and mould surfaces during polymeric micro/nano structures replication, we have used tungsten disulfide (WS2) nanosheets to fabricate high-performance nickel/WS2 nanocomposite mould using electroforming. However, the aggregation of WS2 nanosheets in the electroforming solution is a critical issue that influences the mechanical and tribological properties of the mould. In this study, we first propose a new strategy of combining anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant cetyltrimethylammonium bromide (CTAB) to achieve uniform dispersion and incorporation of WS2 nanosheets in the electroformed nickel mould. Our results indicate that appropriately designing the structure of CTAB-SDS complex can achieve a stable WS2 dispersion, contributing to the uniform co-deposition of WS2 nanosheets into nickel mould. The combination of high concentration of CTAB and SDS (1.0 g/L CTAB and 1.0 g/L SDS) significantly improved the dispersibility and incorporation of WS2 into the nickel matrix, compared to individual SDS or CTAB. Consequently, the maximum hardness enhanced by 350% from 284 HV for pure nickel to 1280 HV for nickel/WS2 nanocomposite mould, along with the coefficient of friction (COF) against the polymethyl methacrylate (PMMA) pin reducing from 0.75 to 0.31. It is also found that CTAB promotes particle encapsulation while SDS improves the particle dispersion but cannot control the particle incorporation. The surface wettability of nickel/WS2 mould altered to hydrophobicity from hydrophilicity of nickel mould, where the adhesion-induced wear caused by polymer pin significantly reduced. Moreover, the surface roughness did not change much with the incorporation of WS2 into the mould, which is acceptable for mould applications. Finally, the nickel/WS2 nanocomposite mould was successfully fabricated via electroforming and its self-lubricating properties was validated by micro hot embossing PMMA microfluidic chips with good surface quality.

Adsorption of CTAB on Sapphire-c at High pH: Surface and Zeta Potential Measurements Combined with Sum-Frequency and Second-Harmonic Generation.

The adsorption of cetyltrimethylammonium bromide (CTA+Br-) on sapphire-c surfaces was studied at pH 10 below the surfactants' critical micelle concentration. The evolution of interfacial potentials as a function of CTAB concentration was characterized by surface and zeta potential measurements and complemented by molecular dynamic (MD) simulations as well as by second-harmonic (SHG) and vibrational sum-frequency generation (SFG) spectroscopy. The changes in interfacial potentials suggest that the negative interfacial charge due to deprotonated surface aluminols groups is neutralized and can be even overcompensated by the presence of CTA+ cations at the interface. However, SFG intensities from strongly hydrogen-bonded interfacial water molecules as well as SHG intensities decrease with both increasing CTAB concentration and the magnitude of the surface potential. They do not suggest a charge reversal at the interface, while the change in zeta potential is actually consistent with an apparent charge inversion. This can be qualitatively explained by results from MD simulation, which reveal adsorbed CTA+ cations outside a first strongly bound hydration layer of water molecules, where they can locally distort the structural order and replace some of the interfacial water molecules adjacent to the first layer. This is proposed to be the origin for the significant loss in SFG and SHG intensities with increasing CTAB concentration. Moreover, we propose that CTA+ can act as a counterion and enhance the occurrence of deprotonated surface aluminols that is consistent with the decrease in surface potential.

Improved membrane permeability with cetyltrimethylammonium bromide (CTAB) addition for enhanced bidirectional transport of substrate and electron shuttles

The effects of membrane permeability on extracellular electron transfer (EET) and performance of microbial fuel cell (MFC) need to be explored. In this work, cetyltrimethylammonium bromide (CTAB) was chosen to enhance the current generation and bidirectional transport of substrate and electron shuttles by tailoring the cell membrane permeability. Specifically, the peak currents of biofilms treated with CTAB especially at 200 μM were obviously higher than the control biofilm with no CTAB, and the riboflavin mediated electron transfer was promoted prominently. Biomass and viability analyses showed that an appropriate concentration of CTAB had almost no adverse effect on the cell viability of biofilm and could increase the biomass of biofilm. Measurements of the extracellular activity of alkaline phosphatase and UV–vis absorption confirmed the increased membrane permeability and the promoted efficiency of substrates transported into cells. This contribution paves the key step for facilitating EET process by adjusting membrane permeability through CTAB or other surfactants addition.

Exploration of the Nucleation-Growth Effect of Cetyltrimethylammonium Bromide for High β-Poly(Vinylidene Fluoride) Crystallization

Poly(vinylidene fluoride) (PVDF, β-phase) exhibits excellent electrical properties because of its all-trans conformation in the crystalline phase, which has attracted much attention in electronic device applications. This paper describes our studies of the cetyltrimethylammonium bromide (CTAB)-induced PVDF crystallization in PVDF thin films via solution crystallization and melt crystallization by compression molding. In the solution crystallization process the relative crystal content of the polar crystals phase of PVDF reached 90% due to the solvent effect and low crystallization temperature. During the melt crystallization process the polar crystal nucleation effect of CTAB (powders) was pronounced. The strong "ion-dipole" interaction between the positive charges on the surface of CTAB and the -CF2 of PVDF promoted the formation of polar crystals. The incorporation of 1 wt% CTAB in PVDF led to the nucleation of polar crystallites up to 97.6%. Additionally, the tensile strength and elongation at break reached 39.8 MPa and 172.5%. The crystallinity of the PVDF increased with an increase in the content of CTAB. The electrostatic interaction between CTAB and the PVDF molecular chains induced and stabilized the all-trans conformation of the PVDF crystals, resulting in PVDF films with high polar phase content, which are expected to be applicable to industrially produced piezoelectric films.

MnCO3 microcubes as an inexpensive catalyst for oxygen evolution reaction

In this study, MnCO3 microcubes (MCs) were successfully synthesized via a simple hydrothermal synthesis method using a fixed amount of MnCl2, urea, and various concentrations (0.2, 0.4, and 0.8 g) of cetyltrimethylammonium bromide (CTAB); these microcubes were labeled as MC-1, MC-2, and MC-3, respectively. The synthesized MCs were used as efficient nonprecious electrocatalysts for the OER in an alkaline medium. Compared with MC-2 and MC-3, MC-1 exhibited a high OER activity, which was evidenced by a lower overpotential of 350 mV at a current density of 50 mA g−1, a small Tafel slope of 109 mV dec-1, and high durability.

Preparation of Bismuth Tungstate Nanomaterials with Different Morphologies and Their Effect on Exercise Rehabilitation of Patients with Lumbar Disc Herniation.

It is understood that the effect of exercise rehabilitation drugs in patients with lumbar disc herniation is poor. Some studies have shown that bismuth tungstate nanomaterials with certain morphology can treat the exercise rehabilitation of patients with lumbar disc herniation. In order to help patients with lumbar disc herniation to a certain extent, in this paper, bismuth tungstate nanomaterials with different structures and morphologies were prepared by hydrothermal method, and viscous tungsten nanomaterials with different structures and morphologies were prepared by adjusting the pH value of the solution and the concentration of CTAB. In this paper, the structure and morphology of tungsten samples with different structure and morphology were characterized by CTAB X-ray (XRD) deflection and FESEM. It was found that the morphology of the samples changed after adding 0.02 mol/L surfactant CTAB in the reaction system, and when the concentration of CTAB was 0.04 mol/L, the nanotubes were stacked together under the action of surfactant. When the concentration of CTAB increased to 0.06 mol/L, the self-assembled nanocomposites tended to be petal like.

The mediated rheological properties of emulsions stabilized by thread-like mesoporous silica nanoparticles in combination with CTAB.

The combination of hydrophilic particles and surfactants provides a simple method to stabilize Pickering emulsions. The type and concentration of the particles and surfactants play important roles in the microstructure and rheological properties of the resulting emulsions. Herein, stable n-octane-in-water Pickering emulsions with tunable rheological properties were prepared using thread-like mesoporous silica nanoparticles (TMSNPs) and cetyltrimethylammonium bromide (CTAB) as emulsifiers. The CTAB concentration (CCTAB) highly affected the properties of emulsions, which were divided into three regions according to the results of large-amplitude oscillatory shear responses. In the low CCTAB range (0.03 mmol L-1 ≤ CCTAB ≤ 0.1 mmol L-1), the emulsions gelled with a high storage modulus . With CCTAB increasing, the value of emulsions, measured by the small-amplitude oscillatory shear, decreased from approximately 1000 Pa at 0.03 mmol L-1 to 100 Pa at 0.3 mmol L-1 and then to 40 Pa at 3 mmol L-1. A three-dimensional percolation structure formed by cross-linking of TMSNPs in the emulsion continuous phase was observed via cryo-SEM in the low CCTAB range but not in the intermediate and high CCTAB ranges. The mechanisms showing the synergistic stability and rheological properties of these emulsions were investigated. It is attributed to the unique morphology of TMSNPs and the competitive adsorption of CTAB molecules at the oil-water interface and on the nanoparticle surface in different CCTAB ranges. Moreover, owing to the porosity and hydrogen-bonding interactions between the TMSNPs and the confinement effect of the flocculated oil droplets, the viscoelasticity of the emulsions could be mediated by adding a trace amount of acid/base. This study provides a new strategy to regulate the rheological properties of emulsions. It also expands the Pickering emulsion systems with tunable rheological properties.