P-toluenesulfonic Acid Research Articles

Microwave-assisted extraction of cellulose and aromatic compounds from rose petals based on deep eutectic solvent

High-value utilization of agricultural wastes such as rose petals promotes the development of the dual carbon economy. In this study, rose petals were pretreated by microwave-assisted deep eutectic solvent (DES). Choline chloride-ethylene glycol (ChCl-EG) was used as the basis for the addition of P-toluenesulfonic acid (TsOH) or Ferric chloride (FeCl3). Forming ternary DESs, as well as designing quaternary DESs with a synergistic effect. The effects of different types of multicomponent DES on treating anthocyanins, cellulose, and lignin in rose flowers were explored. The results showed that the highest anthocyanin extraction of 173.71 mg/g and the highest lignin removal of 40.80 % could be achieved after tetrad DES pretreatment when the molar ratio was ChCl:EG:TsOH:FeCl3 = 1:2:0.3:0.3. The interaction energy between anthocyanins and DES was calculated using density functional theory (DFT), and the maximum was −543.14 kcal/mol. This study demonstrated that DES pretreatment can provide novel insights for the utilization of roses in high-value.

Low-concentration octadecylamine based nano cellulose prepared by acid hydrolysis method improving the toughness and thermal stability of epoxy resin

Modified cellulose nanocrystals were prepared by hydrolyzing softwood pulp board with acrylic acid and p-toluenesulfonic acid, and then the nano cellulose was modified by introducing Octadecylamine into the nano cellulose. Then the modified nano cellulose was dispersed in epoxy resin (EP) to obtain Octadecylamine (ODA) modified nano cellulose-based epoxy resin composites (ONCA/EP) with high strength and good toughness. Moreover, the problem of poor dispersion of nano cellulose in EP is improved. FTIR and X-ray diffraction (XRD) confirmed the modified nano cellulose.The application properties were determined through particle size analysis, thermogravimetric analysis (TGA-DSC), mechanical property analysis, TEM and SEM. ONCA/EP nano composites have excellent mechanical properties and thermal stability due to inadequate concentration of modified nano cellulose doping. The results show that by introducing 2 % ONCA only, the strength reached the highest 74.03 MPa, and the elongation at break reached 3.64 %; the residual mass at 800℃ increased by 3.68 % compared to pure EP. The research utilizes biodegradable nano cellulose for EP modification, opening up new avenues for the applying of nano cellulose in the field of materials science. It is of great significance in enhancing epoxy resin's performance, promoting sustainable materials' development, and expanding the application areas of nano cellulose.

Kinetics and Mechanism of Liquid-State Polymerization of 2,4-Hexadiyne-1,6-diyl bis-(p-toluenesulfonate) as Studied by Thermal Analysis.

A detailed investigation of the liquid-state polymerization of diacetylenes by calorimetric (DSC) and spectroscopic (in situ EPR) thermal analysis techniques is performed. Isoconversional kinetic analysis of the calorimetric data reveals that liquid-state polymerization is governed by a well-defined rate-limiting step as evidenced by a nearly constant isoconversional activation energy. By comparison, solid-state polymerization demonstrates isoconversional activation energy that varies widely, signifying multistep kinetics behavior. Unlike the solid-state reaction that demonstrates an autocatalytic behavior, liquid-state polymerization follows a rather unusual zero-order reaction model as established by both DSC and EPR data. Both techniques have also determined strikingly similar Arrhenius parameters for liquid-state polymerization. Relative to the solid-state process, liquid-state polymerization results in quantitative elimination of the p-toluenesulfonate group and the formation of p-toluenesulfonic acid and a polymeric product of markedly different chemical and phase composition.

LIGNOCELLULOSE BIOMASS DELIGNIFICATION USING ACID HYDROTROPE AS GREEN SOLVENT: A MINI-REVIEW

"Efficient and cost-effective conversion of lignocellulosic biomass into usable forms of energy presents unique challenges. Lignocellulosic biomass, comprising cellulose, hemicelluloses, and lignin, necessitates advanced conversion technologies. Common commercial delignification techniques, including kraft pulping, sulfite pulping, acid hydrolysis, and organosolv pulping, often involve harsh conditions leading to structural changes in lignin and environmental impacts. To address these issues, acid hydrotropes have emerged as a promising method for lignin extraction. Acid hydrotropes, represented by p-toluenesulfonic acid (p-TsOH), enable the solubilization of hydrophobic substances like lignin. This mini-review provides an overview of various lignocellulose fractionation techniques and explores the acid hydrotrope approach. The mechanism behind acid hydrotropic fractionation is discussed, and its performance is evaluated. In conclusion, the review emphasizes the pivotal role of the acid hydrotrope approach in advancing lignocellulosic biomass conversion technology, promoting a sustainable and efficient bio-based economy."

Synthesis of C-tetra(aryl)resorcin[4]arenes using various types of catalysts under solvent free conditions: a comparative study

ABSTRACT A comparative study was carried out between the methods of synthesis of C-tetra(aryl)calix[4]resorcinarenes: by means of reflux, that is to say, carrying out a cyclocondensation reaction catalyzed by hydrochloric acid between resorcinol and different aromatic aldehydes, and by means of the solvent-free method, which is part of the green chemistry methodologies, in which several catalysts were used, viz. p-toluenesulfonic acid, clinoptilolite zeolite, and silica-gel. In the calix[4]resorcinarenes obtained by both methodologies, mainly 2 types of conformers, crown and chair, were observed. The conformers were isolated and characterized via different spectroscopy techniques: FT-IR, HPLC/MS, 1H-NMR, and 13C-NMR. In these solvent-free and reflux reactions, different ratios were obtained for each of the conformers, finding diverse and unexpected ratios for the solvent-free method. On the other hand, for the solvent-free method there was a significant saving of solvent, an important factor in the care of the environment, as well as of energy and time, in addition to minimizing the significant risks involved in the handling of strong mineral acids.

Ligand-Centered Photocatalytic Hydrogen Production in an Axially Capped Rh2(II,II) Paddlewheel Complex with Red Light.

A new series of Rh2(II,II) complexes with the formula cis-[Rh2(DTolF)2(bpnp)(L)]2+, where bpnp = 2,7-bis(2-pyridyl)-1,8-naphthyridine, DTolF = N,N'-di(p-tolyl) formamidinate, and L = pdz (pyridazine; 2), cinn (cinnoline; 3), and bncn (benzo[c]cinnoline; 4), were synthesized from the precursor cis-[Rh2(DTolF)2(bpnp)(CH3CN)2]2+ (1). The first reduction couple in 2-4 is localized on the bpnp ligand at approximately -0.52 V vs Ag/AgCl in CH3CN (0.1 M TBAPF6), followed by reduction of the corresponding diazine ligand. Complex 1 exhibits a Rh2(δ*)/DTolF → bpnp(π*) metal/ligand-to-ligand charge-transfer (1ML-LCT) absorption with a maximum at 767 nm (ε = 1800 M-1 cm-1). This transition is also present in the spectra of 2-4, overlaid with the Rh2(δ*)/DTolF → L(π*) 1ML-LCT bands at 516 nm in 2 (L = pdz), 640 nm in 3 (L = cinn), and 721 nm in 4 (L = bncn). Complexes 2 and 3 exhibit Rh2(δ*)/DTolF → bpnp 3ML-LCT excited states with lifetimes, τ, of 3 and 5 ns, respectively, in CH3CN, whereas the lowest energy 3ML-LCT state in 4 is Rh2(δ*)/DTolF → bncn in nature with τ = 1 ns. Irradiation of 4 with 670 nm light in DMF in the presence of 0.1 M TsOH (p-toluene sulfonic acid) and 30 mM BNAH (1-benzyl-1,4-dihydronicotinamide) results in the production of H2 with a turnover number (TON) of 16 over 24 h. The axial capping of the Rh2(II,II) bimetallic core with the bpnp ligand prevents the formation of an Rh-H hydride intermediate. These results show that the observed photocatalytic reactivity is localized on the bncn ligand, representing the first example of ligand-centered H2 production.

The Rate of Absorption by the Styrene Epoxide–P-Toluene Sulfonic Acid Double System Depending on the Structure of the Aliphatic Tail of the Alcohol Solvent

Oxygen oxidation of the styrene epoxide (SE)–p-toluene sulfonic acid (TSA) double system (DS)in solutions of three primary alcohols, 1-octanol (OCT), n-butanol (BUT), and ethanol (ET), is studied. Thecorresponding concentration expressions of oxidation rates are as follows: VOCT = k [SE]0 [TSA]1, VBUT = k[SE]0 [TSA]0.63, and VET = k [SE]0 [TSA]0.7 at [SE] [TSA]. The proximity of the oxidation activation energiesin three alcohols contrasts with the difference in the oxidation rates: the oxidation rate in ET is threetimes the rate in n-butanol and thirty times the oxidation rate in 1-octanol.

The Rate of the Oxygen Absorption by the Styrene Epoxide–p-Toluene Sulfonic Acid Double System Depending on the Structure of the Aliphatic Tail of the Alcohol Solvent

The Rate of the Oxygen Absorption by the Styrene Epoxide–p-Toluene Sulfonic Acid Double System Depending on the Structure of the Aliphatic Tail of the Alcohol Solvent

Curing Behavior of Sucrose with p-Toluenesulfonic Acid.

With respect to the fossil resources shortage, the development of bio-based wood adhesives is an important research topic in wood science. There has been research on using sucrose for bio-based adhesives. However, a high acid catalyst content and a high hot-pressing temperature are required when manufacturing particleboards. In this study, to explore the possibility of p-toluenesulfonic acid (PTSA) as a promising acid catalyst for sucrose-based adhesives, the curing behavior of sucrose with PTSA (Suc-PTSA) was clarified. The thermal analysis results showed that the thermal properties of sucrose decreased significantly with the addition of PTSA. Based on the results of the insoluble matter rate, the optimal mixture ratio and heating conditions were determined to be 95:5 and 180 °C for 10 min, respectively. According to the results of FT-IR, the heat-treated Suc-PTSA contained furan compounds. In the context of the dynamic viscoelasticity, the onset temperature at which the storage modulus (E') begins to rise was significantly lower than those of the other sucrose-based adhesives. PTSA has the potential to cure sucrose more efficiently and at lower temperatures than previous sucrose-based adhesives, making it a promising acid catalyst for sucrose.

P-Toluenesulfonic acid doped vanadium pentoxide/polypyrrole film for highly sensitive hydrogen sensor

p-Toluenesulfonic acid doped vanadium pentoxide/polypyrrole film for highly sensitive hydrogen sensor

Manufacture and Characterization of PVA-Enzyme/GA/PANI-HCl or PANI-p-toluentsulfonate/PVC-KTpClPB-o-NPOE Indicator Electrode Membranes, Analysis, XRD, SEM-EDX and FTIR

This research aims at the synthesis and characterization of indicator electrode membranes consisting of PVA-Enzyme/GA/PANI/PVC-KTpClPB-o-NPOE, urea analyte. PANI-HCl and PANI-p-toluensulfonate conducting polymers, 61% and 66% o-NPOE plasticizer variations in PVC-KTpClPB, as well as urease enzyme activity in one or three drops of 0.5 mL PVA (50% water: 50% ethanol). The biosensor potentiometric method was used with the technique of immobilizing the urea enzyme which is the urea analyte. The multi-membrane indicator electrode is PVA-Enzyme/GA/PANI/PVC-KTpClPB-o-NPOE, PANI dissolved in HCl and p-toluensulfonic acid respectively at a concentration of 6 M and 2 M. Each membrane on the indicator electrode is coated with one time. Results of XRD analysis of the spectrum pattern of the PANI-HCl indicator electrode with intensities of 4400 a.u, 1386 a.u, 1724 a.u with a 2theta angle of 28.6 degrees, PANI-p-toluensulfonate with intensities of 10940 a.u, 9194 a.u, 5312 a.u with a 2theta angle of 18.2 degrees. SEM-EDX analysis showed differences in the morphology of the o-NPOE plasticizer of 61% and 66% as well as an increase in cps/eV from the number of drops of the urease enzyme, one drop was lower than three drops. FTIR analysis shows an increase in transmittance by PANI towards PPy. Analysis of the properties of a multi-membrane indicator electrode with one layer of the best sample is PANI-p-toluensulfonate

Core-shell Fe3Al@polypyrrole composites with tunable shell thickness and enhanced microwave absorption performance

Nowadays, core-shell structures have attracted considerable attention as microwave absorbers (MAs) due to the synergistic effect between dielectric and magnetic loss. Herein, core-shell Fe3Al@polypyrrole (Fe3Al@PPy) composites were successfully fabricated by the thermit reaction and chemical oxidation polymerization method with the assistance of ammonium persulfate and p-toluene sulfonic acid. Due to the regulation of the impedance matching by the electromagnetic coupling and core-shell structure, the Fe3Al@PPy composites showed enhanced electromagnetic wave (EMW) absorption performance compared with the pure Fe3Al. Furthermore, the thickness of the PPy shell increased from 0.23 µm to 1.50 µm as the addition of pyrrole (Py) increased from 0.25 mL to 1.0 mL. Meanwhile, the core-shell Fe3Al@PPy composites exhibited the optimal wave absorption performance when the PPy shell thickness was 0.80 µm, and the reflection loss (RL) could reach − 40.53 dB with the thickness of 2.0 mm at 13.3 GHz. This work provides a new idea for the design of large-scale electromagnetic (EM) coupled MAs with core-shell structures.

Tween 80 reversed adverse effects of combined autohydrolysis and p-toluenesulfonic acid pretreatment on enzymatic hydrolysis of poplar

In this study, a combined pretreatment involving autohydrolysis and p-toluenesulfonic acid (p-TsOH) was performed on poplar to coproduce xylooligosaccharides (XOSs) and monosaccharides. The autohydrolysis (180 °C, 30 min) yielded 53.2 % XOS and enhanced the delignification efficiency in the subsequent p-TsOH treatment. Furthermore, considerably high glucan contents (64.1 %∼83.1 %) were achieved in the combined pretreated substrates. However, their enzymatic digestibilities were found to be extremely poor (9.6 %∼14.2 %), which were even lower than the single p-TsOH pretreated substrates (10.2 %∼35.8 %). The underlying reasons were revealed by systematically investigating the effects of the single and combined pretreatment strategies on substrate properties. Moreover, the Tween 80 addition successfully reversed the adverse effects of combined pretreatment on the enzymatic hydrolysis, achieving a high glucose yield of 99.3 % at an enzyme loading of 10 filter paper units/g (FPU/g) glucan. These results deepen the understanding of the synergy of combined pretreatment on biomass fractionation and enzymatic saccharification.

The Effect of Anion Modification on the Conductive Polymer/Ag‐Interdigitated Electrodes Micro‐Supercapacitor

Due to their outstanding electrical conductivity, simplicity of synthesis, and exceptional flexibility, conductive polymers are the most attractive electrode materials for micro‐supercapacitors (MSCs). However, when used as an electrode material alone, its poor capacitive performance and cycle‐life hinder the wide engineering applications. Herein, a polypyrrole (PPy)/Ag‐interdigitated electrodes MSCs is proposed, and the impact of aromatic sulfonic acid group anion modification on the electrochemical properties and flexibility of PPy/Ag MSCs is investigated. In the results, it is shown that different aromatic sulfonic‐acid‐based anionic dopants have different effects on the properties of PPy films. Among the prepared three PPy/Ag MSCs devices, PPy:anthraquinone‐2‐sulfonic acid/Ag MSCs have the highest areal capacitance (198.8 mF cm−2) at a current density of 0.5 mA cm−2, surpassing PPy:2‐naphthalenesulfonic acid/Ag MSCs (114.3 mF cm−2) and PPy:p‐toluenesulfonic acid monohydrate/Ag MSCs (89.7 mF cm−2). Furthermore, at a power density of 0.25 mW cm−2, the PPy:AQS/Ag MSCs exhibit a high energy density of 27.61 μWh cm−2, which is above the most of the previously reported PPy‐based MSCs. Therefore, in this research, the groundwork is provided for improving properties of flexible MSCs based on PPy.

Solketal Production Using Eco-Friendly Reduced Graphene Oxide as the Catalyst

In this study, two materials based on reduced graphene oxide (rGOH or rGOE) were synthesized through the Hummers methodology and a more sustainable electrochemical method. These materials were extensively characterized and tested as catalysts in solketal production. Both rGOH and rGOE demonstrated significant catalytic activity, achieving 66.18% and 63.97% conversion rates, respectively. The catalytic activity of the synthesized materials was 30 times more efficient than the homogeneous catalyst p-Toluenesulfonic acid. Pseudo-homogeneous and heterogeneous kinetic models were employed to gain further insights into the glycerol ketalization reaction with acetone. The pseudo-homogeneous model suggested that the direct rate constant was lower than the reverse rate constant. In this sense, a reversible bimolecular reaction was proposed. The heterogeneous kinetic models revealed that in the Langmuir-Hinshelwood-Hougen-Watson mechanism, the controlling step of the reaction was the glycerol-acetone surface reaction on the catalyst. In contrast, in the Eley-Rideal mechanism, the reaction was controlled by the adsorbed glycerol on the reaction surface reacting with the available acetone in the bulk fluid. In the reusability tests, the rGOE catalyst demonstrated superior performance over five consecutive cycles, maintaining the highest activity without needing post-reaction washing or treatment.

The Effect of Organic Acid Dopants on the Specific Capacitance of Electrodeposited Polypyrrole-Carbon Nanotube/Polyimide Composite Electrodes

Energy storage materials are constantly being improved and developed to cope with the ever-increasing demand of the electronic devices industry. Various synthetic approaches have been used to manufacture electrode materials. This paper is focused on the use of intrinsically conductive polymers such as polypyrrole (PPy) in the development of single-walled carbon nanotube-polyimide, SWCNT-PI, supercapacitor electrode materials. The polypyrrole used in the study is doped with different organic acid dopants of various sizes, including styrene sulfonic acid, SSA, toluene sulfonic acid, TSA, dodecylbenzene sulfonic acid, DBSA, naphthalene disulfonic acid, NDSA, and naphthalene trisulfonic acid, NTSA. The number of sulfonic acid functional group per dopant molecule varied from one to three, while the number of benzene rings in the aromatic unit varied from one to two. It is believed that, as the sulfonic acid to the dopant molecule ratio changes, the morphology and electrochemical properties of the doped PPy-coated electrode material will change accordingly. The change in the morphology of the doped PPy, due to the respective dopant, is correlated with the change in the electrochemical properties of the modified composite electrode. The naphthalene trisulfonic acid (NTSA) dopant was found to produce the highest specific capacitance of about 119 F/g at 5 mV/s. Furthermore, the NTSA-doped PPy electrode system showed the highest porosity and highest tan delta damping peak height for the a-transition. The styrene sulfonic acid-doped PPy/SWCNT-PI electrode material showed an impressive storage modulus of more than 2 GPa, but lower porosity. Styrene polymerization is believed to have occurred. The results obtained indicate that the porosity and electrochemical properties of the electrode materials are correlated.

Conversion of artichoke leftovers to levulinic acid: A biorefinery approach

The valorization of agrifood leftovers from an herbaceous plant widely cultivated in Mediterranean areas (Italy and Spain), Cynara scolymus L., is reported here as part of a zero-waste biorefinery approach. The Globe artichoke (GlobART) variety was selected as the source of artichoke leftovers, which were valorized using the following cascade approach: (i) the recovery of antioxidant compounds (AC) still present in the matrix through sustainable microwave-assisted subcritical water extraction (MA-SWE); and, (ii) the subsequent production of levulinic acid (LevA) via the MW-assisted conversion (225ºC, 2 min, 1500 W) of the cellulosic fraction recovered after initial extraction. Preliminary MW-assisted conversion tests on the post MA-SWE GlobART matrix yielded about a 37% yield of LevA (molar yield) using HCl and p-toluenesulfonic acid (p-TsA). Furthermore, performing a delignification step, mediated by either ultrasound (UAD) or MW (MAD), on the post-MA-SWE GlobART matrix before conversion considerably increased LevA yield (55% and 71% from post-UAD and post-MAD GlobART matrices, respectively, with p-TsA). Finally, reducing the KBr/biomass ratio, when using p-TsA, by half afforded an enhancement in LevA yield up to 80% when starting from the post-extraction and delignified (post MA-SWE-& MAD) GlobART matrix.

Comparative study for the separation and depolymerization behavior of lignin from different separation methods

Due to its natural phenolic structure, lignin is the promising feed stock for the production of value-added phenolic monomers. However, the poor understanding of the relationship among separation methods, lignin structure and depolymerization behavior hinders the regulation of phenolic monomers production. In this work, lignin samples were separated by four methods (organic solvent, ionic liquids, deep eutectic solvents, acid-alcohol) using different strategies and their structure difference were characterized and verified by various methods (FTIR, NMR, nitrobenzene oxidation). It was found p-toluenesulfonic acid (PTS) and deep eutectic solvents (DES) were effectively solvents for lignin separation and for structure protection. Highest lignin separation of 99.42% (PTS) and recovery/purity of 92.93%/91.76% (DES) were obtained. The less condensed lignin also showed better performance on mono-phenols production (26.52%). Whereas the condensation C–C bonds formed during separation would hinder the depolymerization and lead to a lower phenolic monomers yield. The research results can provide guidance for the rational selection of lignin separation technology and subsequent depolymerization to produce phenolic monomers.

Flame-retardant and fire-warning cotton composite fabrics based on the thermoelectric effect of polypyyrole doped with P-toluenesulfonic acid

Flame-retardant and fire-warning cotton composite fabrics based on the thermoelectric effect of polypyyrole doped with P-toluenesulfonic acid

Acid-Catalyzed Etherification of Glycerol with Tert-Butanol: Reaction Monitoring through a Complete Identification of the Produced Alkyl Ethers

Higher tert-Butyl glycerol ethers (tBGEs) are interesting glycerol derivatives that can be produced from tert-butyl alcohol (TBA) and glycerol using an acid catalyst. Glycerol tert-butylation is a complex reaction that leads to the formation of five tBGEs (two monoethers, two diethers, and one triether). In order to gain insight into the reaction progress, the present work reports on the monitoring of glycerol etherification with TBA and p-toluensulfonic acid (PTSA) as homogeneous catalysts. Two analytical techniques were used: gas chromatography (GC), which constitutes the benchmark method, and 1H nuclear magnetic resonance (1H NMR), whose use for this purpose has not been reported to date. A method for the quantitative analysis of tBGEs and glycerol based on 1H NMR is presented that greatly reduced the analysis time and relative error compared with GC-based methods. The combined use of both techniques allowed for a complete quantitative and qualitative description of the glycerol tert-butylation progress. The set of experimental results collected showed the influence of the catalyst concentration and TBA/glycerol ratio on the etherification reaction and evidenced the intrinsic difficulties of this process to achieve high selectivities and yields to the triether.