Synthesis of polydiphenylamine with tunable size and shape via emulsion polymerization

Poly(diphenylamine) and its Nanohybrids for Chemicals and Biomolecules Analysis: A Review

Background:

This is the first review on Poly(diphenylamine) and its nanohybrids which covers about 181 references demonstrating the brief discussion on the theoretical studies, chemical, electrochemical and other-phase preparation techniques, polymerization and oxidation-reduction (redox) mechanisms, physicochemical and electrochemical properties along with electrochemical sensors and spectroscopic applications on the detection of chemicals and biomolecules analysis applications.

Objective:

The main aim of this detailed report is merely to afford a survey of the literature existing on this multifunctional conducting organic polymer (poly(diphenylamine)) that provokes a pathway to innovations and discoveries in the near future claim its applications in multidisciplinary fields, especially in the detection of chemicals and bio-molecules applications.

Methods:

We discussed the overall studies on poly(diphenylamine) and its various nanohybrids, including copolymers, homopolymers, carbon-based, and metal/metal-oxide hybrids. The different synthesis methods of poly(diphenylamine) such as chemical/electrochemical/mechano-chemical polymerization in terms of morphology and electrical conductivity were briefly discussed.

Conclusion:

This review manuscript deliberates the various synthesis approaches and applications based on the multifunctional conducting polymer poly(diphenylamine) and its nanohybrids. This review provides an outlook and challenges ahead that ignites spotlight to innovations and discoveries in the near future claim its applications in multidisciplinary fields, particularly in electrochemical sensors and spectroscopic applications towards the detection of chemicals and bio-molecules.

High sensitivity room temperature sulfur dioxide sensor based on conductive poly(p-phenylene)/ZSM-5 nanocomposite

Recently, there has been growing interests in the development of composite materials as the new alternative gas sensing materials for replacing metal oxide based sensors which require the elevated operating temperature. Herein, we reported the fabrication and testing of new sensing composite materials based on the conductive poly(p-phenylene) (PPP) nanoparticle and zeolites for sulfur dioxide (SO₂) detection at room temperature under the effects of doping, zeolite type, zeolite content, SO₂ concentration as well as interferences and humidity. The relative electrical conductivity response depended critically on the doping agent type, doping ratio, and doping temperature. The addition of porous zeolites into the doped-PPP (dPPP) matrix induced the improvement in selectivity and sensing performances towards SO₂ as it promoted more surface area for SO₂ adsorption and its new synergistic effect with the conductive dPPP, related to the additional conductive polymer doping from the dissolution of the SO₂ in intrazeolitic water as identified and reported here. Among all materials, the dPPP/ZSM-5 composite with perchloric acid (HClO₄) as the doping agent, the doping ratio of 50:1, the doping temperature of 70 °C, and the zeolite content of 30% exhibited the highest relative response of 25.42 towards 500 mg L^-1 SO₂ with good repeatability. This composite provided the SO₂ sensitivity of 0.0483 L mg^-1 with R² of 0.9927 and the limit of detection (LOD) of 5 mg L^-1 as determined from the electrical conductivity signal to noise ratio. The present sensing material is a potential candidate in the practical detection of SO₂ at room temperature.

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.

Facile synthesis of highly conductive PEDOT:PSS via surfactant templates

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) nanoparticles in powder form with high electrical conductivity were synthesized via chemical oxidative polymerization. In addition, the effects of EDOT : PSS weight ratio, EDOT : Na₂S₂O₈ mole ratio, and surfactant concentration and type, namely hexadecyltrimethylammonium bromide (CTAB), sodium dodecylsulfate (SDS), and polyoxyethylene octyl phenyl ether (Triton X-100) on the properties of PEDOT:PSS were investigated. For the effect of EDOT : PSS weight ratio, at the EDOT : Na₂S₂O₈ mole ratio of 1 : 1, the EDOT : PSS weight ratio of 1 : 11 was the optimal condition to obtain electrical conductivity of 999.74 ± 10.86 S cm⁻¹ due to the high amount of PSS⁻ and SO₄²⁻ available to interact with the PEDOT chain with a low % PSSNa. For the effect of EDOT : Na₂S₂O₈ mole ratio, at the EDOT : PSS weight ratio of 1 : 11, the EDOT : Na₂S₂O₈ mole ratio of 1 : 2 was the best condition as it provided the highest dopant (PSS⁻ and SO₄²⁻) amount, while the % PSSNa was relatively low. For the effect of surfactant type and concentration, at the EDOT : PSS weight ratio of 1 : 11 and EDOT : Na₂S₂O₈ mole ratio of 1 : 2, Triton X-100 at 2.5CMC provided electrical conductivity higher than with CTAB and SDS. The thermal stability of PEDOT:PSS obtained from various conditions was investigated, and PEDOT:PSS without surfactant showed the highest thermal stability since it produced the highest char yield. In this study, the highest electrical conductivity of PEDOT:PSS, which was obtained in the presence of Triton X-100 to reduce the PSSNa amount, was 1879.49 ± 13.87 S cm⁻¹, the highest value reported to date.

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