P-toluene Sulfonate Research Articles

Non-Substituted Imidazolium-Based Electrolytes as Potential Alternatives to the Conventional Acidic Electrolytes of Polyaniline-Based Electrode Materials for Supercapacitors.

Although disubstituted imidazolium cation is sterically crowded, hundreds of ionic liquids based on this cation have been reported as electrolytes for energy storage devices. In contrast to disubstituted imidazolium, non-substituted imidazolium is uncrowded sterically and has not yet been investigated as an electrolyte, to the best of our knowledge. Hence, imidazolium hydrogen sulfate [Imi][HSO4], in mixture with water, was studied as an electrolyte for PANI-based electrode materials. For comparison, pyrrolidinium with hydrogen sulfate or p-toluene sulfonate ([Pyrr][HSO4] or [Pyrr][PTS]), in mixture with water, were also investigated as alternatives to the conventional electrolyte (i.e., aqueous H2SO4) for PANI electrodes. Walden plots of binary mixture ionic liquid-water weight ratios with the optimal ionic conductivity (i.e., [Imi][HSO4]/water 48/52 wt% (195.1 mS/cm), [Pyrr][HSO4]/water 41/59 wt% (186.6 mS/cm), and [Pyrr][PTS]/water 48/52 wt% (43.4 mS/cm) along with the electrochemical performances of PANI in these binary mixtures showed that [Pyrr][HSO4]aq or [Imi][HSO4]aq are convenient electrolytes for PANI/PIL, as opposed to [Pyrr][PTS]aq. Furthermore, replacing the conventional aqueous electrolyte H2SO4 with [Imi][HSO4] aq increased the specific capacitance of PANI/PIL from 249.8 to 268.5 F/g at 15 mV/s. Moreover, PANI/PIL electrodes displayed a quasi-ideal capacitive behavior in [Imi][HSO4]aq (the correction factor of CPE4 was 0.99). This primary study has shown that non-substituted imidazolium as an electrolyte could enhance the electrochemical performances of PANI electrodes and could be a good alternative to the conventional electrolyte.

Preparation and optimization of dummy molecularly imprinted polymer-based solid-phase extraction system for selective enrichment of p-toluene sulfonate esters genotoxic impurities

Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet–visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1 % phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10 % acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10 ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples.

Investigation of spectroscopic and electrical properties of doped poly(pyrrole-3-carboxylic acid)

The spectroscopic and electrical properties of poly(pyrrole-3-carboxylic acid) doped with p-TSA- (p-toluenesulfonate) and AQS- (anthraquinone sulfonate) were investigated. The variation in electrical conductivity as a function of temperature shows that the systems have semiconductor-like electrical characteristics. The investigated polymers exhibit 3D conductivity and less than 0.6 eV energy gaps. The IR and Raman spectra show that the charge carriers are polarons and bipolarons. Doping the poly(pyrrole-3-carboxylic acid) increases the number of charge carriers. Electron paramagnetic resonance has shown that localized polarons and bipolarons are formed within these polymers.

Dual nonionic photoacids synergistically enhanced photosensitivity for chemical amplified resists

In this paper, 4,5-dimethoxy-2-nitrobenzyl methacrylate (MONMA) was copolymerized with 2-hydroxyethyl methacrylate (HEMA) and tert-butyl methacrylate (TBMA) to obtain the terpolymer with dual sensitivity of ultraviolet (UV) light and acid, P(MONMA-HEMA-TBMA). The nonionic photosensitive ester, 4,5-dimethoxy-2-nitrobenzyl p-toluene sulfonate (MONS), is designed and synthesized as the prime photoacid generator (PAG) because of excellent photoacid generating capability of MONS and the similar substituted structure between MONS and MONMA. The ester groups in MONS PAG small molecules and the MONMA units of P(MONMA-HEMA-TBMA) disintegrate under UV irradiation to generate free diffused sulfonic acids and localized carboxylic acids, respectively. Both free and localized acids facilitate the subsequent acid-catalyzed hydrolysis of TBMA adjacent to MONMA units to induce exponential growth of carboxylic acids. Therefore, the hydrolyzed polymers containing high-content carboxylic acids become soluble in the alkaline developer. Hydrophilic HEMA is introduced to the photoresist resin to improve the interfacial affinity between the resist and the substrate. Dual synergy effect from free photoacid generator MONS and polymerized photoacid unit MONMA enhances photoacid generation and accelerates acid proliferation, which enables the decreased exposure dose and lower content of free photoacid generator MONS. A series of novel chemical amplification photoresists with various methacrylate monomer ratios are designed and synthesized to optimize the photolithographic effect of photoresist resin. The UV photolithography results demonstrate that the distinct exposed patterns are obtained at a low exposure dose using the photoresist formulation with P(MONMA50-HEMA19-TBMA31) and MONS of 9:1 w/w.

Simultaneous and trace-level quantification of four benzene sulfonate potential genotoxic impurities in doxofylline active pharmaceutical ingredients and tablets using high-performance liquid chromatography with ultraviolet detection.

In the production of doxofylline, the common occurrence of toxic p-toluene sulfonate generation prompted the development and validation of a method using HPLC with ultraviolet detection (HPLC-UV). This method is designed for detecting four potential genotoxic impurities (PGIs) present in both doxofylline drug substance and tablets, with a focus on the UV-absorbing group p-toluene sulfonate. The four impurities were methyl 4-methylbenzenesulfonate (PGI-1), ethyl 4-methylbenzenesulfonate (PGI-2), 2-hydroxyethyl 4-methylbenzenesulfonate (PGI-3), and 2-(4-methylphenyl)sulfonyloxyethyl 4-methylbenzenesulfonate (PGI-4). In this method, chromatographic separation was achieved using a Waters Symmetry C18 column (250 mm × 4.6 mm, 5 μm). The mobile phases consisted of 20% acetonitrile as mobile phase A and pure acetonitrile as mobile phase B, operating in gradient elution mode at a flow rate of 1.0 mL/min. According to the guidelines of the International Conference on Harmonization, it was determined that this method could quantify four PGIs at 0.0225 μg/mL in samples containing 60 mg/mL. The validated approach demonstrated excellent linearity (R2 > 0.999) across the concentration range of 30%-200% (relative to 0.075 μg/mL doxofylline) for the four PGIs. The accuracy of this method for the four PGIs ranged from 94.8% to 100.4%. The reverse-phase-HPLC-UV analytical method developed in this study is characterized by its speed and precision, making it suitable for the sensitive analysis of benzene sulfonate PGIs in doxofylline drug substances and tablets.

Characterization of the acoustic cavitation in ionic liquids in a horn-type ultrasound reactor

Most ultrasound-based processes root in empirical approaches. Because nearly all advances have been conducted in aqueous systems, there exists a paucity of information on sonoprocessing in other solvents, particularly ionic liquids (ILs). In this work, we modelled an ultrasonic horn-type sonoreactor and investigated the effects of ultrasound power, sonotrode immersion depth, and solvent’s thermodynamic properties on acoustic cavitation in nine imidazolium-based and three pyrrolidinium-based ILs. The model accounts for bubbles, acoustic impedance mismatch at interfaces, and treats the ILs as incompressible, Newtonian, and saturated with argon. Following a statistical analysis of the simulation results, we determined that viscosity and ultrasound input power are the most significant variables affecting the intensity of the acoustic pressure field (P), the volume of cavitation zones (V), and the magnitude of the maximum acoustic streaming surface velocity (u). V and u increase with the increase of ultrasound input power and the decrease in viscosity, whereas the magnitude of negative P decreases as ultrasound power and viscosity increase. Probe immersion depth positively correlates with V, but its impact on P and u is insignificant. 1-alkyl-3-methylimidazolium-based ILs yielded the largest V and the fastest acoustic jets – 0.77 cm3 and 24.4 m s−1 for 1-ethyl-3-methylimidazolium chloride at 60 W. 1-methyl-3-(3-sulfopropyl)-imidazolium-based ILs generated the smallest V and lowest u – 0.17 cm3 and 1.7 m s−1 for 1-methyl-3-(3-sulfopropyl)-imidazolium p-toluene sulfonate at 20 W. Sonochemiluminescence experiments validated the model.

Piezoelectric properties of ZnO nanowire arrays/DAST-PDMS flexible nanogenerators

The piezoelectric properties of 4-(4-dimethylaminostyryl) methylpyridine p-toluene sulfonate (DAST)-polydimethylsiloxane (PDMS) composite thin film was investigated. Flexible nanogenerators based on zinc oxide (ZnO) nanowire (NW) arrays/DAST-PDMS were fabricated. DAST holds organic crystal structure, and it can possess piezoelectric properties, and it can enhance the piezoelectric properties of ZnO NW arrays. PDMS can not only mix DAST powder with a liquid to prepare a thin film but also protect ZnO NW arrays and DAST from deterioration. When applying pressure with a balance weight of 100 g, the flexible nanogenerator based on ZnO NW arrays/DAST-PDMS can generate an output voltage of 2.3 V, which is much larger than that of the nanogenerator based on ZnO NW arrays. The effect of the strength of vertical external force, frequency of vertical external force, and degree of bending deformation on the ZnO NW arrays/DAST-PDMS flexible nanogenerators were investigated in this Letter. In our experiments, the output voltage of the ZnO NW arrays/DAST-PDMS flexible nanogenerators can reach 3.3 V. After bending the nanogenerator 20 times, the energy collection device based on the ZnO NW arrays/DAST-PDMS flexible nanogenerator was able to light an LED bulb.

Large third-order nonlinear susceptibility of newly synthesized 3-amino-1H-1,2,4-triazolium p-toluene sulfonate (TPTSA) single crystal measured by the open and closed aperture of the Z-scan technique

The researchers employed the Slow Evaporation Solution Technique (SEST) to grow a third-order nonlinear optical 3-amino-1H-1,2,4-triazolium p-toluene sulfonate (TPTSA) crystal and subsequently conducted an X-ray structural examination. The resulting solution's monoclinic structure (P21/c space group) was confirmed and refined using the SHELXS 2018/3 program, and this marks the first instance of a TPTSA single-crystal structure being reported. To further investigate the optical qualities of the TPTSA crystals, including reflectance (R), bandgap (Eg), refractive index (n), and extinction coefficient (K), we utilized a UV–Vis–NIR spectrophotometer, which demonstrated a transmittance of 82%. Moreover, photoluminescence spectrum analysis revealed that the crystal emits light at 294 and 471 nm. Thermal properties of the TPTSA single crystals were also studied, and it was determined that TPTSA remains stable up to 197 °C. A Hirshfeld surface study showed various inter and intra molecular interactions within the TPTSA compound. Based on the crystal's Z-scan parameters, such as absorption coefficient (β = 1.02412 × 10−4 m/W), nonlinear refractive index (n2 = 9.7348 × 10−12 m2/W), and third-order linear optical susceptibility (χ3) of TPTSA, which was found to be 3 × 10−8 esu, it is evident that the nonlinear properties of this crystal make it suitable for third harmonic generation applications. The comprehensive structural analysis and physical characteristics of the TPTSA crystal demonstrate its potential for applications in harmonic generation.

Crystal growth, experimental, theoretical investigation and molecular docking study of ammonium p-toluenesulfonate

Current study looked at theoretical and experimental studies of ammonium p-toluene sulfonate (AMPTS). The optimized structure was studied employing the density functional theory (DFT) approach and the basis set B3LYP/6–311 G (d,p). Strong agreement between Fourier Transform Raman and Fourier Transform Infrared data experimental findings has been demonstrated by DFT research. The computed UV–visible spectroscopic data and the previous published work on the titular material are found to be in line with each other. The charge transfer occurs in the AMPTS molecule, as evidenced by the computed energy gap of the HOMO-LUMO, DOS, and MEP surface. Our title molecule has an enhanced electrophilic character, as seen by the computed global chemical reactivity descriptors. The most important interactions, as determined by the Hirshfeld surface, are H…O/O…H, H…H, and C…H/H…C. Additionally, the presence of intermolecular interactions, such as hydrogen bonding interactions, was clearly shown by the non-covalent interaction via the reduced density gradient (NCI-RDG) research. In order to treat plant diseases, AMPTS ligand was molecularly docked with feruloyl esterase.

2-fluoro-1-methylpyridinium p-toluene sulfonate: a new LC-MS/MS derivatization reagent for vitamin D metabolites

Vitamin D analysis by MS faces several analytical challenges, including inefficient ionization, nonspecific fragmentation, interferences from epimers, isomers, and isobars, as well as very low concentration levels. In this study, we used 2-fluoro-1-methylpyridinium (FMP) p-toluene sulfonate for derivatization of vitamin D3 metabolites to increase detection sensitivity and allow for full chromatographic separation of vitamin D isomers and epimers. UHPLC-MS/MS was used for measurement of five vitamin D3 metabolites in human serum. Compared with Amplifex and 4-phenyl-1,2,4-triazolin-3,5-dion, the FMP p-toluene sulfonate reaction required less time to be performed. The method was optimized and validated to ensure accuracy, precision, and reliability. In-house and commercial quality control samples were used to assure the quality of the results for 25-hydroxyvitamin D3. The method showed very good linearity and intraday and interday accuracy and precision; coefficients of determination (r2) ranged between 0.9977 and 0.9992, relative recovery from 95 to 111%, and coefficient of variation from 0.9 to 11.3. Stability tests showed that the extracted derivatized serum samples were stable for 24 h after storage at −20°C; 24,25-dihydroxyvitamin D3 and 1,25-dihydroxyvitamin D3-FMP derivatives were stable for 1 week at −80°C. The method was applied to samples of healthy individuals for quantitative determination of vitamin D3, the two epimers of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3.

Effect of doping zinc chloride on the growth parameters and the structural, optical, mechanical, thermal, and electrical properties of l-alanine p-toluene sulfonate single crystals

Zinc chloride doped l-alanine p-toluene sulfonate (LAPTZn) was grown by slow evaporation technique. Single crystal X-ray diffraction (SXRD) analysis and powder X-ray diffraction (PXRD) analysis divulges the structural description of LAPTZn crystal. The optical property have been analyzed by UV–Vis spectral analysis and photoluminescence study. The active functional groups present in the LAPTZn single crystal was determined using FTIR and FT-RAMAN analysis. The hardness and thermal stability were analyzed. The chemical composition of LAPTZn single crystal was confirmed using EDAX analysis. Dielectric analysis was also carried out. The third order NLO behavior of the LAPTZn crystal was discussed in Z-scan technique.

Extraction of mangiferin and pectin from mango peels using process intensified tactic: A step towards waste valorization

Simultaneous extraction of mangiferin and pectin from the waste mango peels was attempted with the aim of reducing the number of processing steps, minimizing the operation time and avoiding the requirement of harsh acids. Microwave-assisted extraction has been employed along with different hydrotropes (sodium cumene sulfonate, sodium salicylate, and sodium p-toluene sulfonate) and methanol with varying concentrations. The highest yield of mangiferin (10.43 mg/g) was attained using sodium cumene sulfonate at 80 W microwave power, 10 min time, 0.5 M concentration, 80 °C temperature and 1:50 g/mL solid-liquid ratio. The mangiferin recovery was 20 % higher using hydrotropic solution in comparison to methanol (50 %, v/v). The hydrotropes have concurrently extracted pectin (25.38 %, w/w), which was not possible using methanol. Thus, the incorporation of hydrotropes has led to the avoidance of acidic solution for the recovery of pectin. Pectin has a higher methoxy content (∼ 74 % degree of esterification) and a higher percentage of D-galacturonic acid. The extraction time was further reduced in the range of 50–70 % by embedding sonication with microwave-assisted extraction. Moreover, the extract has exhibited good antioxidant activities (> 70 % DPPH and> 90 % ABTS). A symbiotic effect of hydrotrope, microwave and sonication has resulted in the simultaneous extraction of mangiferin and pectin along-with better processing conditions thereby providing a sustainable option which can be explored at a higher scale. In addition, the present study has presented a judicious utilization of mango waste.

Hydrogen-bonded structure and optical nonlinearities in the proton-transfer complex of 8-hydroxy-5-nitroquinoline with ρ-toluenesulfonic acid

Single crystals of 8-hydroxy-5-nitroquinolinium p-toluene sulfonate (HNT) were grown by the slow evaporation solution growth technique. The structure was elucidated by single-crystal X-ray diffraction analysis, and the crystal belongs to the monoclinic system with the space group C2/c. The crystallinity of HNT was studied by powder X-ray diffraction analysis. The presence of functional groups was determined by FT-IR spectral analysis. The band gap energy is estimated by the application of the Kubelka–Munk algorithm. The charge transfer characteristic of the compound was studied by frontier molecular orbital (FMO) analysis. The first-order hyperpolarizability of the HNT molecule was found to be 285.45 × 10−30 esu, which is ~ 750 times higher compared to the reference urea molecule. Investigation of the intermolecular interactions and crystal studies packing via Hirshfeld surface analysis, based on single-crystal XRD, reveals that the close contacts are associated with molecular interactions. Fingerprint plots of the Hirshfeld surfaces were used to locate and analyze the percentage of hydrogen-bonding interactions. The Mulliken charge of the present molecule was theoretically analyzed. The Kurtz-Perry powder technique has been used to estimate the second harmonic generation. Observed small SHG and large hyperpolarizability are rationalized.

Effect of anionic, cationic and non-ionic surfactants with NaF as binary additives on the performance of soluble lead redox flow battery

The effect of adding sodium lignosulfonate as anionic, hexadecyltrimethylammonium p-toluene sulfonate (HDTMA p-TS) as cationic, or Triton X-100 as non-ionic surfactant along with NaF into the electrolyte as binary additives on the performance behaviour of a soluble lead redox flow battery (SLRFB) is studied by Field Emission Scanning Electron Microscopy (FESEM) and various electrochemical techniques. The FESEM studies show no significant change in the structural morphology of PbO2 deposits in the case of cationic surfactant in conjunction with NaF, whereas sodium lignosulfonate and Triton X-100 in conjunction with NaF show significant changes in the morphology of cathode deposits. FESEM studies reveal that cationic surfactant with NaF facilitates the smooth and lateral growth of Pb deposits. Cyclic voltammetry and kinetic studies show that adding NaF to anionic surfactant is detrimental, while it is found to be beneficial with cationic and non-ionic surfactants. The constant current charge and discharge cycling studies show that cells with pristine electrolyte, anionic surfactant along with NaF, Triton X-100 along with NaF additives show a cycle-life of 25, 75, and 25 cycles, respectively, when charged at 20 mA cm−2 current density and discharged to 0.8 V at the same current density. Interestingly, the cationic surfactant with NaF exhibits a cycle-life of more than 1350 cycles without any maintenance with no deterioration in the performance under similar conditions. To the best of our knowledge, this is the highest cycle-life demonstrated for SLRFB system without any maintenance. Mechanistic insights for the beneficial role of cationic surfactant in controlling Pb dendrite formation are discussed.

Exploring synergistic fire suppression of siloxane-glycoside firefighting foam using sulfonated hydrotrope additives to alter surfactant aggregation in solution

Synergism between siloxane 502W and alkylpolyglycoside Glucopon 225DK surfactants in a mixture has resulted in a foam with firefighting potential. This synergism is not well understood, therefore additives were utilized to alter performance. Hydrotropes sodium benzene sulfonate and sodium p-toluene sulfonate were introduced to alter micelle size while keeping other solution properties constant and their effects were assessed for the individual surfactants and the mixture. Solution properties including micelle size (via dynamic light scattering) were measured along with the heptane vapor transport rate through a foam layer, foam expansion ratio, and fire extinction performance on a 19 cm heptane pool fire using a CO2 absorption measurement. Increased micelle size with hydrotrope addition did not directly correlate with improved fire suppression. Hydrotropes destabilized G225 aggregation, possibly due to G225 inter-surfactant hydrogen bonding potentials, which is limited for 502W. Hydrotropes inhibit the mixture G225 contribution while 502W remains. 502W is less effective individually, resulting in increased fire extinction times for the mixture with hydrotropes. Previously reported mixture synergism may be related to collaboration of individual surfactant contributions. Surfactant roles and inter-surfactant hydrogen bonding potentials are supported by the collected data, but have not been directly measured and require further evaluation.

Low-power, high-performance, and small-footprint, single-pump optical parametric amplifier for photonic integrated circuits

A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) filled silicon-based slotted photonic crystal waveguide (SPCW). The PTS-SPCW has CMOS-process compatibility and offers slow-light enhanced nonlinearity of PTS due to extreme optical confinement in SPCW. The adverse effects of two-photon absorption and free carrier absorption are absent in PTS in the standard optical communication window. The coupled nonlinear Schrödinger’s equations have been modified to analyze the OPA under slow-light propagation. Performances of the OPA are evaluated in both the high- and low- dispersive zones of the structure. The high dispersive zone exhibits high group indices to the operating waves, leading to a high parametric gain (≈31 dB) and high conversion efficiency (≈27 dB) utilizing a 350 μm long PTS-SPCW and a pump power of 65 mW. However, this zone degrades the shape of a ≤10 ps pulse due to self-phase and cross-phase modulation. On the other hand, in the low dispersive zone, a similar parametric gain and conversion efficiency (both ≈29 dB) are attained utilizing a 1250 μm long PTS-SPCW and a pump power of 150 mW. Nevertheless, this zone degrades a 5 ps pulse only after a distance of 1500 μm. The analyses show a 30 nm bandwidth considering a gain above 30 dB. Investigation of the effect of fabrication imperfections shows excellent performance sustainability of the OPA up to a random error of 40 nm. These remarkable performances make this low-powered, small-footprint OPA suitable for achieving tunable optical amplification in photonic integrated circuits.

Controlling tosylation versus chlorination during end group modification of PCL

Synthetic biodegradable materials are commonly used to create constructs for medical devices and tissue engineered constructs. However, many of the homopolymers used in FDA approved devices such as poly(ε-caprolactone) (PCL), poly(lactic acid), or poly(carbonates) lack biogically relevant functional groups to steer biological responses in a controlled fashion. Commonly, an interconversion of the end groups is required to insert addressable moieties for the attachment of biologically active groups. In this study, the activation of the hydroxyl groups of a low molecular weight PCL-diol to the corresponding p-toluene sulfonate ester using p-toluenesulfonyl chloride was performed in both dichloromethane (DCM) and dimethylformamide (DMF). To our initial surprise, we only yielded the chlorinated product in DMF, while in DCM the tosylate ester was obtained. In a small series of reactions, we studied the solvent dependent switchability between tosylation and chlorination on PCL. We concluded that in polar aprotic solvents (DMF and dimethylsulfoxide), we rapidly and efficiently converted the hydroxyl into the chloride group, whereas in inert solvents (DCM and chloroform) we yielded the tosylated product. The data suggested that solvation effects of the polar aprotic solvents led to a Sn2 reaction of the tosyl group by the chloride. Furthermore, we utilized a polyethylene glycol (PEG) polymer to show translatability of the chlorination reaction to other (biomedical) polymers. This work highlights a new reaction pathway during the tosylation of a polymer end group, and presents a new useful strategy to insert clickable groups on synthetic polymers that are only soluble in polar aprotic solvents.

Electrochemical Fabrication and Characterization of Organic Electrochemical Transistors Using poly(3,4-ethylenedioxythiophene) with Various Counterions

Organic electrochemical transistors (OECTs) are promising bioelectronic devices, especially because of their ability to transport charge both ionically and electronically. Conductive polymers are typically used as the active materials of OECTs. Crosslinked, cast, and dried films of commercially available poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) suspensions are commonly and widely used for OECTs so far. Electrochemical polymerization of PEDOT from 3,4-ethylenedioxythiophene (EDOT) monomer can also be used to fabricate OECTs; however, this approach has not been investigated in as much detail. In particular, the role of various counterions that can be incorporated into the PEDOT films of OECTs has not been systematically studied. Here, we report the electrochemical fabrication and characterization of OECTs using PEDOT with several different counterion salts including lithium perchlorate (LiClO4), sodium p-toluene sulfonate (pTS), and poly(sodium 4-styrene sulfonate) (PSS). We found that the characteristic dimensions of PEDOT films deposited on the electrodes could be precisely controlled by total charge density, with a nominal thickness of about one micron requiring a current density of about 0.6 C/cm2 regardless of the choice of counterion. The films with the PSS counterion were relatively smooth, while PEDOT films prepared with the pTS and LiClO4 were much rougher due to the sizes of counterions. The PEDOT films with pTS and PSS grew along the substrate surface (in-plane direction) much faster than with LiClO4. The maximum transconductance (gm) of a PEDOT OECT was 46 mS with pTS as the counterion with the high on-current level (>10 mA) based on the large channel area. These results provide an effective and efficient way to fabricate OECTs with various monomers and additives as active materials in order to modify the device characteristics for further applications.

The effect and enhancement mechanism of hydrophobic interaction and electrostatic interaction on zwitterionic wormlike micelles

The effects of hydrophobic interaction and electrostatic interaction on the structure of zwitterionic wormlike micelles (WLMs) were studied. The change of the hydrocarbon chain length and addition of cetyl trimethyl ammonium chloride (CTAC) were employed to explore the effect of hydrophobic interaction and electrostatic interaction on the wormlike micelles constructed by zwitterionic viscoelastic surfactants and sodium p-toluene sulfonate (NaPts). The experimental results show that increasing hydrocarbon chain length of zwitterionic surfactant and the addition of CTAC can increase the viscoelasticity and zero-shear viscosity of the system. The calculated length of wormlike micelles also increases. This shows that the enhancement of hydrophobic interaction and electrostatic interaction can promote the growth and entanglement of wormlike micelles. In addition, scanning electron microscope (SEM) images confirmed that CTAC makes the connection between the zwitterionic micellar layer closer. This is undoubtedly beneficial to the growth of micellar structure. Finally, this work explores the enhancement mechanism of the hydrophobic interaction and electrostatic interaction on the micelle structure.

Growth, optical, thermal, electrical, mechanical, and antibacterial activity of hexa aqua nickel bis (P-toluene sulfonate) (HNPS) single crystal

The conventional slow evaporation technique is used in the growth of semi-organic single crystals of Hexa aqua nickel bis (P-toluene sulfonate) (HNPS) and the monoclinic system with centrosymmetric space group (P21/n) is corroborated by single-crystal X-ray diffraction analysis. FTIR vibrational analysis inferred the presence of water molecules CH3 and SO3 groups in grown HNPS crystals. Linear optical parameters explored by UV–Visible spectral analyses ensures the high optical activity of HNPS. The green light emission of HNPS was attributed to Photoluminescence analysis. Thermal analysis encapsulates the thermal stability of HNPS crystals up to 590 °C. The dielectric nature of the material was analyzed for various frequencies at room temperature and an increase in DC conductivity of HNPS suggests the semiconducting behavior of the material while heating. The work hardening coefficient is quantified as 3.7 using mechanical analysis. The thermal and mechanical stability suggests the specific application of HPNS in device fabrications. The synthesized HNPS was tested against two gram-positive bacterial strains (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacterial strains (Escherichia coli, Pseudomonas aeruginosa) and showed higher significant antibacterial activity against the pathogen.