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Naturally derived biopolymers have been widely used for biomedical applications such as drug carriers, wound dressings, and tissue engineering scaffolds. Chitosan is a typical polysaccharide of great interest due to its biocompatibility and film-formability. Chitosan membranes with controllable porous structures also have significant potential in membrane chromatography. Thus, the processing of membranes with porous nanoscale structures is of great importance, but it is also challenging and this has limited the application of these membranes to date. In this study, with the aid of a carefully selected surfactant, polyethyleneglycol stearate-40, chitosan membranes with a well controlled nanoscale structure were successfully prepared. Additional control over the membrane structure was obtained by exposing the suspension to high intensity, low frequency ultrasound. It was found that the concentration of chitosan/surfactant ratio and the ultrasound exposure conditions affect the structural features of the membranes. The stability of nanopores in the membrane was improved by intensive ultrasonication. Furthermore, the stability of the blended suspensions and the intermolecular interactions between chitosan and the surfactant were investigated using scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. Hydrogen bonds and possible reaction sites for molecular interactions in the two polymers were also confirmed by FTIR analysis.

The 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) nanoparticles were prepared by using semibatch reaction crystallization method, and the influencing factors in close relationship with the grain size and crystal morphology control, such as the concentration of reaction system and categories of surfactants, were studied in this paper. The synthesized nano-TATB particles had been characterized by SEM, XRD, thermo gravimetric/differential scanning calorimetric (TG/DSC) and N₂ physisorption. The grain size of TATB particles using nonionic surfactant as the additive ranged from 30 nm to 65 nm with a shape of spheres or ellipsoids. The broadening of the peaks and the weakening of the strength for nano-TATB were observed by XRD analysis. The corrected average particle size of nano-TATB was calculated using the Debye–Scherrer equation and the range was from 18 nm to 50 nm. TG and DSC curves revealed that thermal decomposition of nano-TATB occurred in the range of 361.5°C–385.0°C and its peak temperature was 373.7°C with a decrease of approximately 7°C compared with original TATB. Furthermore, the specific surface area (21.54 m²/g) of nano-TATB was calculated by BET method using N₂ physisorption (at 77°C).

A surfactant system L64 and alcohol mixture was employed to exfoliate MoS₂. To reduce the impact of surfactant on the quality of the nanosheet, the concentration of L64 was decreased to an extremely low value 0.0325 mM. Utilize common ultrasonic bath, the production yield of the nanosheet was increased to about 5% per hour, and statistical results from AFM showed that 40% of the nanosheet were less than 4 nm thick. Rheology characterization showed that surfactant alcohol mixtures were shear thinning fluid, yet the viscosity of L64 system varies directly with the shear rate in the high-speed shear region (higher than 400 s⁻¹), and further affect the shear strength, therefore viscosity at high-speed shear can be considered as an indicator of the effectiveness for the exfoliation system. Exfoliated MoS₂ was evaluated by hydrogen evolution reaction, and compared to the bulk MoS₂, the 4 wt% Pt/FL-MoS₂ improved the overpotential from 366 mV to 273 mV at 10 mA$•$cm${}^{-2}$. This study presented a facile and effective route to fabricate 2D MoS₂ with much less residue, and bring more opportunities to exploit clean and nontoxic system to exfoliate 2D materials.

Supercapacitors require excellent cycling stability and rate capability for electrodes. The NiCo₂S₄ spinel structure has caught much attention for its high conductivity and high theoretical specific capacity. However, due to the lack of active sites, it has been restricted in supercapacitors. In this research, the NiCo₂S₄ nano-material with needle, sheet and porous network morphologies were prepared by the addition of different kinds of surfactants via a simple hydrothermal method. At 1mA/cm², capacitance of these NiCo₂S₄ nanomaterials is measured as 2.09F/cm², 3.22F/cm², and 4.42F/cm², respectively. It was found that the exposure ratio of (111) and (220) crystal facets also has an effect on electrochemical performance, and NiCo₂S₄ with I${}_{(111)}$/I${}_{(220)}$ of 3:1 showed better performance. Furthermore, NiCo₂S₄-PN//AC asymmetrical supercapacitor was assembled with NiCo₂S₄-PN serving as positive electrode and activated carbon (AC) as negative electrode. At a power density of 7.284mW/cm², energy density achieved was 0.625mWh/cm². Additionally, capacitance retention rate remained at 79.6% of initial capacitance after 1500 cycles. These outcomes are of great significance for developing more efficient, stable and reliable transition metal sulfide-based supercapacitors.

In this paper, a circular three-layer flow model is proposed to study mucus transport in the airways due to air motion caused by mild forced expiration or mild coughing. Mucus is represented by four-parameter viscoelastic fluid, a combination of Maxwell and Voigt elements, whereas air and serous fluid are taken as Newtonian fluids (incompressible). The pressure gradient generated in the fluid layers is assumed to be given by a time-dependent function representing mild forced expiration or mild cough in the airways causing laminar flow. The effect of slip velocity at the mucus–serous interface caused by the presence of surfactant and at the top surface caused by immotile cilia are also taken into account. The roles of rheological properties of mucus on its transport are studied. The effect of serous fluid and its viscosity on mucus transport is also considered.

In this research Sr-hexaferrite powder was synthesized by a sol–gel auto-combustion route using two different fuels (glycine and citric acid) and two different basic agents (ammonia and trimethylamine). N-decyltrimethylammonium bromide (C₁₃H₃₀BrN) was also employed as a cationic surfactant. The results showed the finest crystallite size and the lowest calcination temperature have been obtained as 27.2 nm and 800 °C respectively, in the presence of citric acid, trimethylamine and surfactant.

In the field of nanoscience, the ability to prepare high-quality nanocrystals is crucial for fundamental research and technology development. Herein, we review a general route for the colloidal preparation of monodisperse nanocrystals, which is divided into five different stages, namely (i) nucleation, (ii) growth, (iii) Ostwald ripening, (iv) surfactant capping and (v) precipitation. Each of the five stages is discussed in detail to provide a comprehensive understanding of the mechanism behind nanocrystal formation and the subsequent processing steps. We put emphasis on the classical theories and experimental techniques that are most frequently practiced. These are useful for the successful design and fabrication of nanocrystals with properties that are beneficial for use in a plethora of technological applications.

There is increased concern about the associations between particulate air pollution and human health. Inhaled and deposited particles play a crucial role in the aetiology of a range of pulmonary diseases. A variety of pulmonary diseases develop from the inhalation and deposition of pathogenic organisms or noxious particles (e.g. viruses, bacteria, spores, pollen, etc.). The inhalation of soot, burned tobacco and paper leads to common pulmonary diseases: chronic bronchitis and lung cancer.

It has been suggested that ultrafine particles might be taken up by cells, including by airway epithelial cells, through a process related to the surface forces exerted on them at the cell membrane–particle interfacial region.

Carbon nanofibers (CNFs) were coated by surfactants of polyoxyetheylene alkyl ether (AEO₉, AEO₇) and polyvinyl alcohol (PVA 1799), respectively, after being mixed with surfactant aqueous solution and then treated with ultrasonication, high shear and magnetic stirring. The CNF/epoxy composites were prepared by mixing the surfactant coated CNFs with epoxy. Tensile strength, elastic modulus and ultimate strain of the composites were studied. The tensile strength and the ultimate strain of the composites were increased by 20% and 70%, respectively, after the CNFs were coated by surfactants. However, the elastic modulus of the composite will be lowered when the CNFs were treated by too high a concentration of surfactant solution.

A new type of organophilic clay gallant was discovered in which the organic cations derived from organic salt compounds provide improved gelling properties in organic solvents. It was discovered that that the tail length of the surfactants can affect the suspension property of organically modified sepiolite significantly. Furthermore, it has been discovered that surfactant CTAB has stronger suspension properties than the other three surfactants, accompanying with an 80% suspension value. The present research provides an improved, more efficient organophilic clay gellant for gelling or thickening non-aqueous solvent-based compositions. Besides, the results of SEM demonstrate that the introduction of CTAB is favorable to the dispersion of sepiolite fibers, leading to a better suspension value of sepiolite suspensions. Besides, FTIR spectra analysis indicate that the formation of hydrogen-bonding during the adsorption of surfactant molecules onto the sepiolite particles.

Surfactant based fracturing gels are considered as clean gel due to absence of insoluble residues after hydraulic fracturing of tight reservoir. Conventionally used highly viscous polymer gels damage the formation by blocking the fluid path in fractured formation. The present work has been accomplished with the purpose of evaluating an anionic surfactant based gel for hydraulic fracturing. Rheological properties of the synthesized gel were studied as a function of shear rate, temperature and pH which are considered to be the most effective parameters on the gel behavior at the downhole. Proppant carrying capacity was also reported with varying proppant loading.