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Electrodes composed of nanostructured surfaces have been shown to be promising electrocatalysts, offering enhanced catalytic activity. Gold nanoparticles (AuNPs) are often used to produce such a nanostructured surface. However, these are commonly prepared using a reductant and surfactant, often hindering the electrocatalytic application of the surface. In the present study, we fabricated a nanostructured gold thin film electrode derived from a solution of AuNPs containing only Au, H, and O, which was prepared by solution plasma processing in the presence of hydrogen peroxide. The concentrated AuNP dispersed aqueous solution was dropped onto the glassy carbon substrate and then dried to form a AuNP thin film at room temperature. The resultant gold film was nanostructured owing to the presence of the AuNPs, could be used directly in electrochemical reactions without pre-treatment (such as surfactant/reductant removal), and gave stable voltammetric responses, indicating its suitability as an electrode material. In addition, the AuNP thin film electrode exhibited enhanced electrocatalytic activity compared with conventional planar gold electrodes, which can be attributed to its surface nanostructure. In particular, the electrocatalytic current in the hydrogen evolution reaction was more than 10 times larger at the nanostructured AuNP thin film electrode than at a planar gold electrode. Further, the AuNP thin film electrode enabled direct electron transfer (DET) between a redox enzyme, neuroglobin, and the electrode surface, while the planar electrode showed no DET response. The results indicate the usefulness of the present AuNP thin film electrode, prepared by a reagent-free process, for various electrocatalytic applications.

An attempt has been made to combine interfacial polymerization with a fast mixing technique without the use of surfactant. Effects of mixing speed, reaction time, temperature, oxidant-to-monomer molar ratio and nitric-to-monomer molar ratio were tested for electrical conductivity and polyaniline nanofiber size. The findings demonstrate that the diameter of polyaniline nanofiber can be reduced by optimising the synthesising parameter, thereby increasing the electrical conductivity of polyaniline nanofiber. Infrared spectroscopy has shown increased amplitude of the main absorption peak of polyaniline nanofiber during the conversion of aniline to conductive polyaniline nanofiber. The crystalline nature of polyaniline nanofiber has been discovered by the X-ray diffraction spectra. Hall effects experiments have shown that the electrical conductivity of polyaniline nanofiber has improved from 5.2 to 17.5 Scm−1 with an increase in homogenizer speed. The morphological properties of polyaniline nanofiber through electron microscopy scanning have confirmed the decreasing size of polyaniline nanofiber from 50-60 nm to 20–30 nm by increasing the homogenizer speed to 30,000 rpm. These findings demonstrate that higher homogenization speed can split the solution to smaller molecules during polymerization contributing to the creation of smaller nanofiber sizes.

While triboelectric nanogenerators (TENGs) made of biomaterials are becoming significant components of self-charged monitoring healthcare systems, most of them show low output performance and poor durability. Herein, a surfactant-free graphene oxide-polylactic acid (GO/PLA) nanocomposite with customizable honeycomb patterns was, for the first time, prepared via a scalable two-step solution method to achieve a power-boosted biocompatible TENG. The first step of this method involved using a suitable solvent (such as dimethylformamide) to well disperse the GO nanoparticles into PLA. Subsequently, honeycomb patterns were induced by using a mixture of chloroform and methanol as a suitable volatile solvent/nonsolvent pair for improved phase separation. The results indicated that GO nanoparticles with large surface area and abundant electron-donating groups decorated the honeycomb patterns and significantly influenced the electro-positivity and surface properties of the PLA bio-polymer. An unprecedented antagonistic TENG (A-TENG) based on the concave-honeycomb GO-PLA (hc-GO/PLA) and its corresponding convex-polydimethylsiloxane (c-PDMS) form a pair of tribo-components with antagonistic friction surfaces and generate an output power of 3.25 mW, which is 13.6 times higher than that of a flat-surface TENG (f-TENG) without GO additives. We believe that the incorporation of functional GO nanoparticles without surfactants expands the potential applications of biocompatible A-TENG in healthcare areas thanks to its boosted output performance and persisting biocompatibility.

Recently, oxidative desulfurization (ODS) is favoured by researchers because it is based on mild conditions and does not consume hydrogen. However, the preparation process of catalyst for ODS was not green or costly, which limits its further industrial applications. In this study, a facile route has been explored to grow the mesoporous MoO 3 /SiO 2 nanosphere networks (MoO 3 /SiO 2 NN) using low-cost air without surfactants. Herein, the air not only served as the template to self-assemble and form the nanosphere network structure but acted as a mesopore-directing agent to make mesopores on the MoO 3 /SiO 2 nanosphere. Moreover, the recovered waste mother liquor was also successfully applied to prepare nanomaterials. Gratifyingly, the nanocomposites of MoO 3 /SiO 2 NN displayed remarkable pore structure, large specific surface area (201 m 2  g -1 ) and excellent amphipathy (CA = 24.7° and 13.6° of water and n-octane, respectively) making it a promising catalyst for two-phase ODS reaction with H 2 O 2 as an oxidant. Meanwhile, the high TOF value (56.6 h -1 ) and outstanding durability were obtained under optimum conditions (Yield > 99 % at 70 °C and O/S = 8:1 for 1 h, 20 mg catalyst) and the products were detected by GC-MS and 1 H NMR. Therefore, an environmentally benign self-assembly procedure can facilely prepare more types of mesoporous catalysts for large-scale industrial application., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Despite the widespread use of surfactants, there are known issues such as allergic reactions and formulation complications in their use as emulsion stabilizers. In this study, stabilizer-free water-in-oil (W/O) emulsions containing water, phytantriol, and almond oil were prepared by an ultra-turrax homogenizer, a standard laboratory equipment, and a high specialized high-shear device. Parameters such as mixing time, stirring rate, composition, order of addition of phases, and temperature were investigated to systematically optimize the preparation of the formulations through evaluating their accelerated physical stability by a centrifugal sedimentation technique. The liquid crystalline structure of the continuous phase was studied by small-angle X-ray scattering indicating a reverse hexagonal phase (H 2 ). Microscopy images showed the emulsions prepared via high-shear method had smaller water droplets with more uniform shape and better dispersion as confirmed by Fourier-transform infrared-attenuated total reflection spectroscopy. Rheology studies showed a larger yield stress value for emulsions with higher content of phytantriol. Our results indicated that emulsions prepared by the high-shear device with higher amount of phytantriol were the most stable formulations. Applying the correct variables in the preparation of the stabilizer-free emulsions using ultra-turrax homogenizer, one could obtain similarly stable emulsions lacking the uniformity of the droplets., (Copyright © 2020 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

In this study, ZrO 2 layer coated silica microspheres (ZrO 2 /SiO 2 ) were successfully prepared by a facile one-step surfactant-free hydrothermal route under low pH condition. The synthesized ZrO 2 /SiO 2 material was then modified with d-fructose 1, 6-bisphosphate (FDP) to improve the chromatographic separation property of the material. Fused-silica capillary columns were prepared with the modified material for evaluation. Phenolic, nucleobases and alkaloids compounds in hydrophilic interaction chromatographic (HILIC) mode showed symmetrical peaks. The FDP-ZrO 2 /SiO 2 stationary phase showed better performance than ZrO 2 /SiO 2 packing material and demonstrated great potential for application in HILIC mode., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Herein, we prepared PEI-immobilized core-shell particles possessing various types of polymer cores via a visible light-induced surfactant-free emulsion polymerization (SFEP) of three vinyl monomers: styrene (St), methyl methacrylate (MMA), and 2-hydroxyethyl methacrylate (HEMA). An effect of monomers on the polymerization and characteristics of resulting products was investigated. Monomers with high polarity can provide high monomer conversion, high percentage of grafted PEI, stable particles with uniform size distribution but less amino groups per particles. All prepared nanoparticles exhibited a core-shell nanostructure, containing PEI on the shell with hydrodynamic size around 140-230nm. For in-vitro study in Caco-2 cells, we found that the incorporation of PEI into these core-shell nanoparticles can significantly reduce its cytotoxic effect and also be able to internalized within the cells. Accordingly, these biocompatible particles would be useful for various biomedical applications, including gene transfection and intracellular drug delivery., (© 2013.)