Synthesis and Characterization of Hollow-Sphered Poly(N-methyaniline) for Enhanced Electrical Conductivity Based on the Anionic Surfactant Templates and Doping

Poly(N-methylaniline) (PNMA) is a polyaniline derivative with a methyl substituent on the nitrogen atom. PNMA is of interest owing to its higher solubility in organic solvents when compared to the unsubstituted polyaniline. However, the electrical conductivity of polyaniline derivatives suffers from chemical substitution. PNMA was synthesized via emulsion polymerization using three different anionic surfactants, namely sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and dioctyl sodium sulfosuccinate (AOT). The effects of surfactant structures and concentrations on electrical conductivity, doping level, crystallinity, morphology, and thermal stability were investigated. The re-doping step using perchloric acid (HClO4) as a dopant was sequentially proceeded to enhance electrical conductivity. PNMA synthesized in SDBS at five times its critical micelle concentration (CMC) demonstrated the highest electrical conductivity, doping level, and thermal stability among all surfactants at identical concentrations. Scanning electron microscopy (SEM) images revealed that the PNMA particle shapes and sizes critically depended on the surfactant types and concentrations, and the doping mole ratios in the re-doping step. The highest electrical conductivity of 109.84 ± 20.44 S cm−1 and a doping level of 52.45% were attained at the doping mole ratio of 50:1.

A non-surfactant self-templating strategy for mesoporous silica nanospheres: beyond the Stöber method

The “pre-Ouzo” structure directed synthesis of mesoporous silica nanoparticles (MSNs) in the absence of surfactant templates probably also explains the origin of highly monodisperse size distribution of classical Stöber silica NPs.

Straight-forward Synthesis of Sponge-sphere like Cobalt Tungstate: An Efficient Photocatalyst for Dye Degradation

Herein, we attempted for the synthesis of novel sponge-sphere like cobalt tungstate nanoparticles (CoWO4 NPs) via simple co-precipitation technique without using any surfactant/templates. The as-prepared CoWO4 NPs were characterized by various analytical and spectroscopic techniques such as XRD, FT-IR, SEM, EDX, UV-Visible and elemental mapping analysis. The photocatalytic activity of as-prepared nanoparticles was investigated by the degradation of cationic dye methylene blue (MB) under visible light irradiation. It exhibited excellent photocatalytic degradation with a decolorization efficiency of 94% within 90 min. In addition, this work gives a novel application of CoWO4 NPs in environmental remediation.

Synthesis of Uniform Mesoporous Zeolite ZSM-5 Catalyst for Friedel-Crafts Acylation

This work highlights how the treatment of ZSM-5 (parent Zeolite Socony Mobil–5, Si/Al = 23) with different surfactant templates and alkaline solution, improved the catalytic performance in the Friedel-Crafts acylation of anisole with a propionic anhydride to obtain p-methoxypropiophenone. The modified microporous to mesoporous zeolite catalysts were characterized using different analytical techniques, including X-ray diffraction (XRD), nitrogen porosimetry, Fourier-transform infrared spectroscopy (FT-IR), temperature-programmed desorption (ammonia-TPD) and field emission scanning electron microscopy (FE-SEM) to analyze the crystallographic structure, surface acidity, surface area, porosity, morphology, and particle size. The results showed that the formed mesoporous zeolite by NaOH solution had smaller mesopores (ca. 3.7 nm) as compared to the mesoporous zeolites obtained by surfactant templates, such as, CTAB (ca. 14.9 nm), TPAOH (ca. 11.1 nm) and mixture of CTAB/TPAOH (ca. 15.2 nm). The catalytic acylation reaction was conducted in a batch glass reactor at various temperatures and the products were analyzed using off-line gas chromatography–mass spectrometry (GC-MS). It was found that the activity of treated ZSM-5 with mixed surfactant templates (CTAB/TPAOH) exhibited enhanced selectivity towards the main product (p-methoxypropiophenone) by a factor 1.7 or higher than unmodified ZSM-5 due to its increased surface area by 1.5 times and enhanced acid sites.

Facile synthesis of highly conductive PEDOT:PSS via surfactant templates

The electrical conductivity of 1879.49 ± 13.87 S cm−1 was achieved for PEDOT:PSS, which is the highest value reported to date.

Rice Starch-Templated Synthesis of Nanostructured Silica and Hematite

Synthesis of nanostructured materials is not straightforward, which involves the complicated use of surfactant templates. Currently, only non-renewable resources that are hazardous and toxic are used to produce the surfactant templates in the industries. This study presents an environmentally friendly and efficient route for the synthesis of the nanostructure of both silica and hematite using rice starch as a promising biomaterials template. The rice starch-templated synthesis yield both hematite and silica with nano-size and high surface area. In particular, the nanostructured silica showed a pseudo-spherical morphology with a nano-size from 13 to 22 nm, amorphous structure and surface area of 538.74 m2/g. On the other hand, the nanostructured hematite showed a spherical-shaped morphology with a nano-size from 24 to 48 nm, and surface area of 20.04 m2/g. More importantly, the use of rice starch-template for a greener approach in the synthesis of nanomaterials was successfully outlined.