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This work engrosses the production and further chemical modifications of EPS produced by Lactobacillus plantarum BR2 and subsequent evaluation of their biological properties showed greater antioxidant properties for the derivatives compared to its native unmodified form. Of the three derivatives, acetylated EPS (a-EPS), carboxymethylated EPS (Cm-EPS), and sulphated EPS (s-EPS), a-EPS exhibited the highest DPPH radical scavenging and total antioxidant activity in a dose-dependent manner. At all tested concentrations, a-EPS showed higher scavenging activity, and a maximum activity of 73.81% at 2 mg/mL. Meanwhile, s-EPS showed the highest reducing power potential and hydroxyl radical scavenging activities. At 2 mg/mL concentration, the order of reducing power was observed to be s-EPS (41.39%) > a-EPS (37.43%) > Cm-EPS (24.02) > BR2 control EPS (16%) and the hydroxyl radical scavenging activity for the s-EPS was 54.43%. The highest reducing power activity exhibited by s-EPS is 2.6-fold higher and a 1.5-fold increase in the scavenging activity of native BR2 EPS after the sulphonyl group addition was observed. The increase in these activities is due to the addition of various functional groups that contributes largely to the scavenging abilities of different free radicals. The s-EPS and Cm-EPS derivatives also exhibited increased cholesterol-lowering activity of 40 and 34.5%, respectively, than the native EPS. Interestingly, there were hardly any inhibitions on cell growth and viability of normal L929 fibroblast cell lines upon treatment with these EPSes. The improved antioxidant properties resulting from chemical modification opened better avenues for EPS application in the food and pharma sectors. Thus, the potentiality of chemically modified EPS may be explored further in the development of functional foods. [ABSTRACT FROM AUTHOR]

A synthetic composite material membrane was synthesized using Polyether ether ketone (PEEK) as a polymer matrix, reinforced with nano-Hydroxyapatite (nHAp) as the ceramic for intended use as a hip bone implant material. Notwithstanding its close resemblance with hip bone material, PEEK is chemically and biologically inert and comes with limited biocompatibility. HAp has chemical and crystallographic similarity with carbonated apatite like human bones. In the present work it was used as reinforcement with PEEK in varying weight percentages, of 2, 5, 8 and 10 to determine the optimum mix for application as a bio hip implant material. HAp reinforcement beyond 10 wt. % was not considered as it resulted in agglomeration and reduction in mechanical properties. The polymer was sulphonated to facilitate chemical interactions with the hydroxyl (-OH) group of HAp to overcome poor interfacial bonding between PEEK and nHAp. The sulphonation also reduced the chances of wear debris from implant site getting resorbed into the body. These synthetic composite samples were then characterized using techniques such as x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope and energy dispersive x-ray spectroscopy, to ascertain its conformity in structure and morphology. Mechanical tensile tests were also carried out to determine tensile strength, yield strength and elastic modulus of the composite membranes. The synthesized sample, with 8 wt. % of HAp reinforcement, demonstrated the most suitable properties. The work propounds a fresh approach towards synthesizing a composite membrane using Polyether ether ketone, subjected to sulphonation (SPEEK), for intended application as a hip implant. The superior surface wetting, obtained on account of sulphonation of PEEK matrix, facilitated more intimate contact with nano-hydroxyapatite (nHAp) reinforcements and assisted in establishing superior, homogeneous and improved mechanical properties throughout the membrane. [ABSTRACT FROM AUTHOR]

Chemithermomechanical pulp (CTMP) is often used in middle layers of multiply paperboards due to its high bulk at specified strength. Such a CTMP should consist of well-separated undamaged fibres with sufficient bonding capacity. The basic objective of this work is to examine the effect of refining on bulk, taking into account conditions such as temperature, sulphonation, refining gap and refiner size. First stage CTMP made from Norway spruce (Picea abies) were produced in pilot and mill scale trials. Two new parameters, Equivalent temperature related to softness and Refining gentleness are introduced that take into account refining conditions as actual temperature, softening temperature, bound sulphonate content, refining gap and refiner diameter. The results show that bulk increases linearly with refining gentleness. [ABSTRACT FROM AUTHOR]

Pure neem seed oil (NSO) was epoxidized via in situ conventional method using hydrogen peroxide and acetic acid in the presence of a microwave-assisted carbon-based sulphonated melon seed peel catalyst (MACSMSPC). The MACSMSPC was prepared via a two-step process (carbonization and sulphonation) using a microwave. The characterization results from Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Micrograph (SEM), X-Ray Diffraction (XRD), Brunauer-Emmet-Teller (BET) and X-ray fluorescence analysis (XRF) confirms the successful -SO3H group attachment to the solid catalyst. The modelling and optimization studies of the epoxidation process of NSO were performed using Box Behnken design implementing Response Surface Methodology (RSM) with catalyst concentration, time and temperature as the independent factors and oxirane value as the dependent factor. The ANOVA showed a second-order polynomial model with an R2 value of 0.9901, Adj R2 of 0.9774 and Pred R2 of 0.8415, indicating the significant correlation between the experimental values and predicted responses. The 3D plots showed that the process parameters significantly impacted the oxirane value. The optimal oxirane value of 9.816% was obtained at a catalyst concentration of 0.6, reaction time of 4 h, reaction temperature of 50 °C with a desirability of 1.000. also, characterizations result via FT-IR and GCMS on the epoxy NSO indicate the oxirane ring's successful attachment on the NSO.

The present study is intended to adopt a facile method for preparing a sulphonated green carbon catalyst from date pits biomass. Catalyst synthesis involves in situ carbonization and sulphonation and it has been characterized by following techniques such as XRD, SEM, EDX, TEM, FTIR, TGA, and BET. Surface and internal morphology results exhibited that the synthesized sulphonated carbon material possesses a mesoporous structure, while activated carbon possesses a microporous structure. Furthermore, the Fourier transform infrared (FTIR) spectra confirmed the presence of acidic groups (OH, COOH, and SO 3 H) in synthesized sulphonated carbon material. Sulphonated carbon material exhibited high acidity (4.7 mmol/g) and good thermal stability. The application of this catalyst for the tertiary butylation of phenol without using any solvent has been investigated. The phenol alkylation reaction showed maximum conversion at reaction condition: temperature (140 °C) with 2 bar (nitrogen gas) pressure with maximum phenol conversion 79.27 wt%, with 68.01% selectivity towards 4TBP+2,4TBP, which is used as an intermediate in antioxidants. The catalyst exhibits comparable catalytic performance up to five reaction cycles. Thus it can be concluded that waste date pits can be successfully employed for green catalyst synthesis and used for reactions involving large molecules. [ABSTRACT FROM AUTHOR]

This work focuses on two different environmental problems: the recovery of plastic wastes PMMA (W PMMA) and their application in the removal of textile dyes Methylene Blue (MB) and Basic Yellow 28 (BY28) in aqueous solutions. The selected waste plastic was upgraded to produce an adsorbent suitable for dyes removal. For that, the material was grinded cryogenically up to a particle size of less than 100 μm and treated with sulfuric acid. The sulphonated waste PMMA (SW PMMA) was characterized by FTIR, scanning electronic microscopy (SEM) and chemical composition analysis (C, H, N, O and S content). The formation of sulphonic groups in the material after sulphonation reaction has been successfully demonstrated by FTIR, and can be observed mainly in the region 3087 cm−1 to 3657 cm−1, where an intense band bound to the stretching of the SO3H appeared; another absorption band appeared in the region from 1138 to 1271 cm−1 that corresponds to the symmetric stretching of the SO2 group. The effects of solution pH, initial dyes concentration, adsorbent dose and temperature were studied in batch experiments. The obtained data showed that SW PMMA adsorbent exhibit significant adsorption capacities of 97.09 mg g−1 and 222.22 mg g−1 for MB and BY28, respectively. The complete removal of MB and BY28 on the SW PMMA was achieved in less than 45 min. The Langmuir, Freundlich and Temkin models were applied and it was found that the equilibrium data could be satisfactory fitted to Langmuir adsorption isotherm. The kinetic study showed that the pseudo second order kinetic model correlates the experimental data. Furthermore, the thermodynamic parameters were determined for both dyes. As a result, the negative values of Gibbs free energy ∆G° indicated the spontaneity of the adsorption of MB and BY28 by SW PMMA. The negative values of ∆H° revealed the exothermic nature of the process and the negative values of ∆S° suggest the stability of MB and BY28 on the surface of SW PMMA. [ABSTRACT FROM AUTHOR]

• Synthesis of SO 4 -2/ZrO 2 -Al 2 O 3 heterogeneous acid catalyst by wetness impregnation process. • Characterization of synthesized catalyst by TGA, XRD, BET, FTIR, XPS, SEM-EDX, and NH 3 -TPD. • Optimization, endurance capacity, E-factor studies, and comparative study. • 99.2% of glycerol conversion with 98.1% of solketal yield was achieved within 180 min of reaction time at 70 °C temperature. • Efficient acetalization reaction of glycerol with acetone showed high TOF following a cleaner and greener route. The exponential growth of biodiesel production generates an enormous amount of glycerol as a by-product that requires effective strategies to convert it into valuable chemicals to enhance the sustainability of the biodiesel market. Solketal is an interesting compound among various value-added chemicals obtained from waste glycerol produced during biodiesel production. In the present work, highly efficient and economically viable heterogeneous solid acid SO 4 -2/ZrO 2 -Al 2 O 3 catalyst was designed via wetness impregnation process. The synthesized catalyst was found to be highly active for acetalization of glycerol with acetone under optimized conditions viz. 1:10 M ratio of glycerol and acetone, 3 wt.% of catalyst loading at 70 °C for 180 min reaction time. The synthesized catalyst is highly selective (98.9%) for solketal synthesis, with 98.1 % yield and 99.2 % glycerol conversion. Green metrics studies were performed to determine the environment-friendly nature of the catalyst and acetalization process. The carbon balance studies were also calculated to show that glycerol is found only in one phase during the overall process of solketal synthesis. The high thermal stability and catalytic activity were retained up to 5th reaction cycle making the catalyst more efficient for its wide application in an industrial level. [ABSTRACT FROM AUTHOR]

The object of the research is multi-stage integrated production of linear alkylbenzenes and linear alkylbenzene sulfonic acid. The established thermodynamic and kinetic laws of the transformations of C9-C14 hydrocarbons and the activity of catalysts used in the synthesis of linear alkylbenzenes provided the creation of mathematical models suitable for optimizing the main stages of the synthesis. the assessment of the full range of nonstationarity factors caused by the deactivation of catalysts was made on the basis of a computational and industrial experiment simulation. the model calculations allowed improving the efficiency of multistage production of alkylbenzene sulfonic acid and to increase the desired product yield from 170-172 to 174-176 tones/day. [ABSTRACT FROM AUTHOR]

Polysaccharides were extracted from Pleurotus eryngii (PEPS) and sulphonated. Anti-inflammatory activities of PEPS and sulphonated PEPS (S.PEPS) were tested on RAW264.7 macrophages in four experimental models. Cytokines of IL-1β, IL-6, IL-10, and TNF-α were quantified by ELISA. Cytokine secretion ratios (IL-1β/IL-10, IL-6/IL-10, and TNF-α/IL-10) were significantly decreased by PEPS and S.PEPS treatments in a dose dependent manner in all four experimental models. Anti-inflammatory activity of S.PEPS was significantly stronger than that of PEPS, and the S.PEPS exhibited stronger reactive oxygen species (ROS) and nitric oxide (NO) inhibition activities compared with those of PEPS. Additionally, S.PEPS also had significantly stronger anti-proliferative activities on both Caco-2 and HepG2 cells compared with those of PEPS. Results indicated that sulphonation improved the anti-inflammatory and anti-proliferative activities of PEPS significantly.

Polyethylene has great potential as an alternative material for carbon fiber production. Polyethylene can be processed in the economic melt spinning process. These precursors are prepared for the subsequent process step of carbonization by using chemical stabilization (sulphonation). The strategy is to adjust these precursor properties by the melt spinning process, thus resulting in a precursor, which can be stabilized sufficiently by sulphonation. The objective is to find the correlation between precursor properties and the results of the sulphonation. In this paper, the chemical stabilization is described and the results of the chemical stabilization are discussed. The novelty in this paper is that the results of the sulphonation are brought in correlation with the precursor properties. It can be shown that the filament diameter and the polymer structure (e.g., the crystallinity) of the precursor have an influence on the sulphonation process.

In this study, we propose a novel conducting and soluble polyaniline salt prepared by chemical polymerization in the presence of new doping agent (IAs). This last is prepared by sulphonation of itaconic acid (IA) with concentrated sulphuric acid in THF. The obtained doped polyaniline (PANI-IAs) is extremely soluble in dimethyl sulfoxyde (DMSO) at room temperature, in which the solubility reach 44 mg mL-1. The conductivity measurement of doped polyaniline powder precipitated in THF as dispersing medium gave a value of 0.13 S cm-1 when the emeraldine base form of polyaniline is fully protonated. The polyaniline salt sample is characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction, UV-Visible spectra and FTIR spectra.

Abstract: Low‐cost bagasse and microcrystalline cellulose were used as the raw materials to prepare solid acid catalysts via incomplete carbonization and sulphonation. The solid acid synthesized from microcrystalline cellulose (C‐SO3H) exhibited better catalytic performance than that synthesized from bagasse. C‐SO3H was characterized by various techniques to study the reaction conditions of the catalytic transformation from glucose and fructose to 5‐hydroxymethylfurfural (5‐HMF). The conversion of glucose was 73.29 ± 0.74 %, and the conversion of fructose reached a maximum of 98.85 ± 0.01 %. The selectivity and yield of 5‐HMF reached maxima of 65.04 ± 0.28 % and 64.29 ± 0.27 %, respectively. Using C‐SO3H as the catalyst, the conversion of glucose followed second‐order kinetics at various temperatures, while the conversion of fructose followed first‐order kinetics. The activation energies of the glucose and fructose transformations were 73.75 and 51.87 kJ · mol−1, respectively. [ABSTRACT FROM AUTHOR]

The effect of cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) on base hydrolysis of iron(II)-triazine complexes viz., tris((3-(4-phenyl)-2-pyridyl)-5,6-bis(4-phenyl)-1,2,4-triazine)iron(II), Fe(PPDT) 3 2+ and its sulphonated analogue, tris(3-(4-(4-phenylsulphonic acid)-2-pyridyl)-5,6-bis(4-phenyl sulphonic acid)-1,2,4-triazine)iron(II), Fe(PPDTS) 3 7‐ has been studied under pseudo -first order conditions at 25, 35, 45 and 55 °C. These reactions are first order with respect to the substrate and hydroxide ion. The rate of base hydrolysis of Fe(PPDT) 3 2+ decreases with the increase in ionic strength in both aqueous and CTAB media whereas the effect is minimal in SDS medium. In the case of Fe(PPDTS) 3 7‐ , the opposite is seen i.e., the rate of hydrolysis increases with the increase in ionic strength in both the aqueous and SDS media whereas in CTAB medium it has little effect. Specific rate constants ( k 2 ) and activation parameters, E a , ΔH # , ΔS # and ΔG # have also been evaluated. The results obtained suggest that these reactions occur essentially by the same mechanism in aqueous and micellar media. About 10 4 times catalysis and 5 times inhibition were noticed in CTAB and SDS media respectively when compared to aqueous medium. The observed catalysis is ascribed to electrostatic and hydrophobic interactions between hydroxide and CTAB ions, whereas the inhibition is attributed to the electrostatic repulsions between hydroxide ion and dodecyl sulphonate anions. Density functional theory (DFT) calculations were found to support the experimental results. [ABSTRACT FROM AUTHOR]

Nanostructured humidity sensors have been facilely prepared by solvent annealing of polystyrene- b -poly(4-vinylpyridine) deposited on interdigitated gold electrodes and subsequent sulphonation. The structure, composition, morphology and hydrophilicity of the block copolymer (BCP) have been characterized by gel-permeation chromatography, 1 H NMR, FT-IR, elemental analysis, scanning electron microscopy and static water contact angle measurements. Phase separation of the BCP film induced by annealing in CHCl 3 vapor and hot ethanol resulted in its fishnet-like porous nanostructure. Humidity sensing properties of the nanostructured BCP based sensor have been examined at room temperature, and the sensing mechanism was examined. Both concentration of polymer solution for film preparation, and the sulphonation duration seriously affected the sensing properties of the BCP based sensor. Under optimal conditions, the BCP based sensor demonstrated high response magnitude towards relative humidity (RH) (impedance change of three orders of magnitude in the range of 40–90%RH). Moreover, it was featured with quick response (t 90% of 10 s and 13 s for humidification and desiccation, respectively), good sensing repeatability and relatively small hysteresis (∼5%RH), which is attributed to its special nanostructure. The desirable sensing performance suggests the potentials of the BCP with phase separation-induced nanostructures as high performance humidity sensing material. [ABSTRACT FROM AUTHOR]

The article presents results of experimental analysis of alkylaromatics composition in paraffins dehydrogenation process feed flow. It was shown that during the technological stages, as a result of dealkylation and polymerization processes, these substances adversely affect the equipment. At the HF-catalyst regeneration stage their presence leads to compression of inter-draining period, as heavy aromatics accumulate mainly in the column bottom. In sulphonation reactor it manifests itself as viscous component formation, sulphonation uniformity disfunction and compression of inter-washing period. Recommendations concerning the processes optimization depending on alkylaromatics composition in the feed flow are provided. [ABSTRACT FROM AUTHOR]

A commercial packing polystyrene had been modified via sulphonation process yielding an efficient ion-exchanger for softening of water . Some factors that have to do with such transformation had been followed up . It had been found that sulphonation conditions, molecular weight, residence time and additives have roles to play.

Glycerol derived from biodiesel (BD) production is oversupplied and requires urgent utilization. Hence, crude bio-derived glycerol was utilized as a carbon precursor for heterogeneous solid acid catalyst synthesis via partial sulphonation and carbonization in a single step. The as-synthesized catalyst was utilized to catalyze glycerol acetylation reaction with acetic acid to produce oxygenated fuel additives (diacetin and triacetin) and monoacetin. Under reaction conditions of 110 °C, glycerol-to-acetic acid molar ratio of 3, 2 wt% catalyst dose, and 3 h reaction time, 88% combined DAG and TAG selectivity was attained with a corresponding glycerol conversion of 99%. The high surface acid sites density of the catalyst primarily contributed to its enhanced catalytic performance. The catalyst displayed sufficient heterogeneity and robustness in polar reaction media despite high hydrophilic acid sites density. Hence, it was reused in seven cycles of the experiment without experiencing significant deactivation. [ABSTRACT FROM AUTHOR]

Polysaccharides extracted from Pleurotus eryngii (PEPS) and Streptococcus thermophilus ASCC 1275 (EPS) were sulphonated and their composition determined. Antioxidant activities of crude and sulphonated polysaccharides (S.PEPS and S.EPS) were investigated using the ABTS radical scavenging test and CCD and Caco-2 cell models. Degrees of sulphonation for S.PEPS and S.EPS were 0.73 and 0.37, respectively. Results showed that S.PEPS and S.EPS had significantly higher scavenging capacities than PEPS and EPS in the ABTS radical scavenging test. Reactive oxygen species and malondialdehyde in H 2 O 2 treated CCD 841 CoN (CCD) and Caco-2 cells were significantly inhibited by PEPS, EPS, S.PEPS and S.EPS compared to the control group. Additionally, S.PEPS and S.EPS significantly improved superoxide dismutase, catalase and glutathione peroxidase activities in H 2 O 2 treated CCD and Caco-2 cells compared to PEPS, EPS and control groups. Results indicated that sulphonation was effective in improving antioxidant activities of both PEPS and EPS. [ABSTRACT FROM AUTHOR]

Pathological crystallization of calcium oxalate (CaOx) inside the urinary tract is called calculi or kidney stone (Urolithiasis). CaOx exhibits three crystalline types in nature: CaOx monohydrate COM, dihydrate COD and trihydrate COT. COD and COM are often found in urinary calculi, particularly COM. Langmuir monolayers, membrane vesicles, phospholipids' micelles, among others, have been adopted as simplified biomimetic template-models to study in vitro the urolithiasis through CaOx. The nucleation and crystal growth of COM on self-assembled lipid monolayers have revealed that the negatively charged phosphatidylserine interface is a strong promoter of COM. Herein, we describe the synthesis and physicochemical characterization of diazotated sulphonated polystyrene films (DSPFs), prepared from various aminocompounds varying their polarity degree i.e., polar, non-polar and acidic DSPF derivatives. We also used these DSPFs as polymeric templates in crystallization experiments of CaOx in vitro. Images obtained by optical microscopy and scanning electron microscopy confirmed the precipitation of COM crystals on the DSPF surface. The employment of functionalized polymeric films as templates for CaOx crystallization represents a viable approach for understanding inorganic mineralization. [ABSTRACT FROM AUTHOR]

Se realizó un conjunto de experimentos de sulfonación de dodecilbenceno (DDB) y ésteres metílicos (ME) derivados de la esteari- na hidrogenada de palma, con SO3 gaseoso desorbido del óleum, en un reactor de sulfonación en película líquida descendente a escala banco de 40 cm de longitud y ½ pulgada de diámetro interno. Mediante titulaciones volumétricas se determinaron los porcentajes de materia sulfonada y contenido de ácido sulfúrico, así como el porcentaje de aceite libre mediante extracciones con éter de petróleo. La funcionalidad del reactor se verificó efectuando ensayos a condiciones reportadas por Gutiérrez y cola- boradores para dodecilbenceno sulfonado (DDBS), para lo cual fueron determinadas las técnicas de análisis en el Laboratorio de Ingeniería Química (LIQ) de la Universidad Nacional de Colombia, sede Bogotá, con el acompañamiento de la empresa Química Básica Colombiana (Caloto, Cauca). Finalmente, se procedió a evaluar la influencia de diferentes variables de proce- so sobre la sulfonación de la mezcla de ésteres metílicos. Los resultados obtenidos en el sulfonador se ajustaron por regresión li- neal múltiple a ecuaciones empíricas, obteniendo expresiones que muestran de forma directa el efecto de variables como la re- lación molar SO3/ME, concentración de SO3 en la corriente gaseosa y flujo másico de ME.

Exopolysaccharide (EPS) produced by Streptococcus thermophilus GST-6 in skim milk was extracted and purified. The EPS was composed of glucose and galactose in a molar ratio of 1.80:1.03 with identical primary structure to the EPS from S. thermophilus ST1 reported previously. The purified EPS was sulphated at a sulphonation degree of 0.26 ± 0.03, and presence of sulphate groups in the sulphated EPS (SEPS) was confirmed. Microstructural studies demonstrated a porous web with coarse surface for the EPS while the SEPS appeared as stacked flakes with relatively uniform shapes. Sulphonation of the EPS slightly decreased its degrading temperature from 234.6 °C to 232.5 °C. The DPPH, superoxide and hydroxyl radicals scavenging activities of the EPS were significantly (P < 0.05) improved after sulphonation. The SEPS also showed stronger inhibitory activity than the EPS against Eschericia coli , Salmonella typhimurium and Staphylococcus aureus . [ABSTRACT FROM AUTHOR]

Polysaccharides were extracted from Pleurotus eryngii (PEPS) and sulphonated. Anti-inflammatory activities of PEPS and sulphonated PEPS (S.PEPS) were tested on RAW264.7 macrophages in four experimental models. Cytokines of IL-1β, IL-6, IL-10, and TNF-α were quantified by ELISA. Cytokine secretion ratios (IL-1β/IL-10, IL-6/IL-10, and TNF-α/IL-10) were significantly decreased by PEPS and S.PEPS treatments in a dose dependent manner in all four experimental models. Anti-inflammatory activity of S.PEPS was significantly stronger than that of PEPS, and the S.PEPS exhibited stronger reactive oxygen species (ROS) and nitric oxide (NO) inhibition activities compared with those of PEPS. Additionally, S.PEPS also had significantly stronger anti-proliferative activities on both Caco-2 and HepG2 cells compared with those of PEPS. Results indicated that sulphonation improved the anti-inflammatory and anti-proliferative activities of PEPS significantly. [ABSTRACT FROM AUTHOR]

The sulphonation of organic-inorganic composite materials was performed both by the sulphuric and chlorosulphonic acids. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of residual organic modifier grafting, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature, amount of sulphonation agent. Strong acidic media could results in partial destruction of organic modifier layer of composite material. Treatment of silylized materials in 20-fold excess of sulfuric acid results in formation of hydrophilic phase. The competitive adsorption of toluene and water data demonstrates the increase in quantity of the adsorbed water from 30 mg/g for MCM-41 to 110-280 mg/g for sulphonated materials. This results in reduction of the Hydrophobicity Index from 5.00 for MCM-41 to 0.3-0.9 for mesoporous material sulphonated by sulfuric and chlorosulphonic acids, respectively. Mild conditions of sulphonation in trichloromethane or acetic anhydride at temperature 275 K increase the hydrophilicity of composites and results in significant increasing of the surface area and pore volume in comparison with the material silylated by chlorodimethylphenylsilane. The TG/DTA data demonstrates high hydrophilicity of sulphonated mesoporous composites based on MCM-41 and high affinity to water molecules with 50-58 % weight loss at 25-100 °C. [ABSTRACT FROM AUTHOR]

This article discusses reasons leading to formation of highly viscous component in linear alkylbenzenes sulphonation reactor of alkylbenzene sulphuric acid production. It was found that highly viscous homologs of tetralin are formed in aromatic compounds dealkylation reactions with subsequent polymerization of alkenes. Infringement of mixture viscosity negatively the affects the uniformity of sulphonation process and reduces the quality of target product. [ABSTRACT FROM AUTHOR]

The presented paper is devoted to research on stability of alkylation and sulphonation units joint work in alkylbenzene sulphuric acid manufacturing. The reasons of equipment unstable operation and product quality deterioration in the stages of benzene alkylation with olefins and alkylbenzenes sulphonation were determined. Using the developed mathematical models of these processes uncontrolled temperature rise in the bottom of HF-catalyst regeneration column forecasting was carried out. Study of sulphonation and alkylation units stability in dependence on aromatics flow rate in alkylator was also performed. [ABSTRACT FROM AUTHOR]

With the goal of enhancing overall carbohydrate recovery and reducing enzyme loading refiner mechanical pulping and steam pretreatment (210 °C, 5 min) were used to pretreat poplar wood chips. Neutral sulphonation post-treatment indicated that, although the lignin present in the steam pretreated substrate was less reactive, the cellulose-rich, water insoluble component was more accessible to cellulases and Simons stain. This was likely due to lignin relocation as the relative surface lignin measured by X-ray photoelectron spectroscopy increased from 0.4 to 0.8. The integration of sulphite directly into steam pretreatment resulted in the solubilisation of 60% of the lignin while more than 80% of the carbohydrate present in the original substrate was recovered in the water insoluble fraction after Na 2 CO 3 addition. More than 80% of the sugars present in the original cellulose and xylan could be recovered after 48 h using an enzyme loading of 20 mg protein/g cellulose at a 10% substrate concentration. [ABSTRACT FROM AUTHOR]

Pathological crystallization of calcium oxalate (CaOx) inside the urinary tract is called calculi or kidney stone (Urolithiasis). CaOx exhibits three crystalline types in nature: CaOx monohydrate COM, dihydrate COD and trihydrate COT. COD and COM are often found in urinary calculi, particularly COM. Langmuir monolayers, membrane vesicles, phospholipids’ micelles, among others, have been adopted as simplified biomimetic template-models to study in vitro the urolithiasis through CaOx. The nucleation and crystal growth of COM on self-assembled lipid monolayers have revealed that the negatively charged phosphatidylserine interface is a strong promoter of COM. Herein, we describe the synthesis and physicochemical characterization of diazotated sulphonated polystyrene films (DSPFs), prepared from various aminocompounds varying their polarity degree i.e., polar, non-polar and acidic DSPF derivatives. We also used these DSPFs as polymeric templates in crystallization experiments of CaOx in vitro. Images obtained by optical microscopy and scanning electron microscopy confirmed the precipitation of COM crystals on the DSPF surface. The employment of functionalized polymeric films as templates for CaOx crystallization represents a viable approach for understanding inorganic mineralization.

We report the use of sulphonated waste polystyrene (SWPS) in the removal of heavy metal ions from water. Waste polystyrene (WPS) comprising of high impact polystyrene (HIPS) and expanded polystyrene (EPS) collected from dump sites in Harare were activated through sulphonation to produce a cation-exchange resin. The presence of the sulphonic group was studied with fourier transform infrared spectroscopy (FTIR). Flame atomic absorption spectrometry (FAAS) was used to determine the concentrations of residual metals (Zn 2+ , Pb 2+ ) after batch adsorption experiments. Sulphonated HIPS reduced Zn 2+ from 80 to 38.3 mg/L compared to 10–1.6 mg/L for sulphonated EPS. Similarly, sulphonated HIPS reduced Pb 2+ from 100 to 33 mg/L compared to 80–50.3 mg/L for sulphonated EPS. The adsorption data followed both the Langmuir and Freundlich isotherms and pseudo-second order kinetics. Maximum adsorption capacities as quantified by the Langmuir parameter q max for HIPS was 5.01 mg/g, EPS 0.38 mg/g for Zn 2+ and HIPS 6.80 mg/g, EPS 0.68 mg/g for Pb 2+ . The data were analysed using pseudo first order and pseudo second order Lagergren equation and the adsorption kinetics of the metals Pb 2+ and Zn 2+ was found to follow the pseudo second order kinetic model. Interpretation of the sorption data in terms of separation factor ( S F ) suggested that the removal of Pb 2+ and Zn 2+ from water mainly occurred through chemisorption. [ABSTRACT FROM AUTHOR]

Industrial production of ether antiknock substances (e.g. ETBE or TAME) involves the use of catalysts based mainly on acidic ion-exchange resins. However, the use of such resins causes certain drawbacks leading to technological difficulties and for this reason the search for other catalysts suitable for the purpose is continued. Our studies were focused on the synthesis of tert -amyl methyl ether (TAME) in which different modified activated carbons were tested as catalysts. The modifications were undertaken to introduce sulphonic groups on the surface of activated carbon, as a result of reactions with such reagents as concentrated or fuming sulphuric acid, in situ generated diazonium salt of 4-aminobenzenesulphonic acid or sodium sulphide and hydrogen peroxide. For the sake of comparison, the activated carbon with P-containing and/or O-containing groups on the surface and the commercial catalyst Amberlyst-15 were used. The most effective method of SO 3 H groups introduction has been proved to be the reaction of activated carbon with in situ generated diazonium salt. The majority of catalysts obtained were active in tert -amyl methyl ether synthesis, however, significant differences in yields of TAME were observed, depending on the method of activated carbon modification. [ABSTRACT FROM AUTHOR]

To efficiently deliver stavudine (d4T) for AIDS therapy, chitosan–stavudine conjugate (Cs–d4T) was synthesized. However, its poor water-solubility limited its clinical application. In this study, a sulphonated chitosan–stavudine conjugate (SCs–d4T) was synthesized with a mild SO 3 ·Py complex sulphonation strategy. Chemical characteristics and morphology of Cs–d4T and SCs–d4T were performed by NMR, XRD, FTIR, ICP-AES and SEM. SCs–d4T demonstrated satisfactory solubility (106-bold of Cs–d4T solubility), good anti-HIV activity (6-fold of d4T anti-HIV activity), and well sustained release ability. The major release product O -isopropyl-5′- H -phosphonate of d4T (d4T-P-H) showed higher anti-HIV activity than d4T. For further evaluating the influence of linker and sulphonation strategy on anti-HIV activity, chitosan grafted with d4T by succinyl linker (Cs–sd4T) and SCs–d4T sulphonated by oleum were also prepared. The result showed that the O -isopropyl monophosphate linker of Cs–d4T and SO 3 ·Py complex sulphonation strategy revealed higher anti-HIV activity than succinyl linker of Cs–sd4T and oleum sulphonation strategy, respectively. [ABSTRACT FROM AUTHOR]

Polysaccharides from Pleurotus eryngii (PEPS) and exopolysaccharides from Streptococcus thermophilus ASCC 1275 (ST1275 EPS) were sulphated, and antioxidant and antibacterial activities of sulphated and crude polysaccharides were determined. Degree of sulphonation of PEPS and ST1275 EPS was 0.69 and 0.31, respectively. Characteristic bands in FT-IR spectra indicated that the sulphate group was at the C6 position of the galactose skeleton. Antioxidant activities of PEPS and ST1275 EPS were significantly (P<0.05) improved after sulphonation. For tested crude and sulphated polysaccharides, sulphated PEPS had the largest inhibition zone against Escherichia coli ATCC 25922 and Staphylococcus aureus CMCC 26003 while sulphated ST1275 EPS had the largest inhibition zone against Listeria monocytogenes CMCC 54001. Furthermore, sulphated PEPS had the lowest minimum inhibitory concentration (MIC) for E. coli ATCC 25922, and both sulphated PEPS and sulphated ST1275 EPS had the lowest MICs on S. aureus CMCC 26003 and L. monocytogenes CMCC 54001. [ABSTRACT FROM AUTHOR]

The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. [ABSTRACT FROM AUTHOR]

A simple procedure was developed for the synthesis of sulphonic group-functionalised silica material (SAM) under formic acid conditions without the presence of surfactant species or precursors. The organic–inorganic hybrid materials exhibited high catalytic activity and excellent thermal stability in the alkylation of aromatics with olefins. Pyridine-FTIR indicated that SAM has abundant Lewis acid sites, especially weak acid sites. 29 Si and 27 Al MAS NMR confirmed that aluminium methanesulphonate was anchored on the surface of the silica matrix by the covalent bond of Si–O–Al. [ABSTRACT FROM AUTHOR]

The Zn2+ and Ni2+ adsorption capacities of six biosorbents derived from water hyacinth (Eichhornia crassipes) (WH) and sawdust (SD) were investigated, with activated carbon as the control. The biosorbents were raw biomass (WH, SD), charred WH (BWH) and SD and sulphonated bio-chars of WH and SD. The effect of the initial solution pH and Zn2+ and Ni2+ concentrations on adsorption capacity was studied, and adsorption isotherms for Zn2+ and Ni2+ evaluated. The initial solution pH significantly influenced adsorption (p<0.05) but the relationship was generally nonlinear. Zn2+ suppressed Ni2+ adsorption on all biosorbents. The adsorption capacities of the biosorbents were statistically (p ⩽ 0.05) similar to or higher than that of activated carbon. The effects of pyrolysis and bio-char sulphonation on adsorption were inconsistent and dependent on biomass type; in most cases bio-char was a better biosorbent than the original biomass, while sulphonation resulted in less or comparable adsorption. Adsorption data obeyed at least one of three isotherms (linear, Langmuir and Freundlich) (r2 = 0.90-0.995, p< 0.05). The study revealed that low-cost biosorbents may be used as alternatives to activated carbon in applications including selective separation of Zn2+ from multi-metal ion solutions containing Ni2+, and water and wastewater treatment. [ABSTRACT FROM AUTHOR]

In this study, a random copolymer of poly(styrene-co-acrylic acid) (PS-AA) was synthesized in solution by radical polymerization and partially crosslinked with divinyl benzene to improve mechanical resistance. The copolymer (PS-AA) was sulphonated with different theoretical molar quantities (20–60%) of sulphuric acid (H 2 SO 4 ) and acetyl sulphate (CH 3 COOSO 3 H). The sulphonated PS-AA materials were characterized with infrared spectroscopy (FTIR), insoluble material percentage by soxhlet extraction, molar mass by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). FTIR indicated the presence of sulphonic groups bound into the copolymer matrix and some changes in specific bands. Gel percentage was considerably increased when H 2 SO 4 was used as the sulphonation agent while a drop in molecular weight was detected by GPC with acetyl sulphate as the agent. The former effect is due to linkages through the sulphone groups and the latter as a consequence of a polymer matrix destructive side reaction. DSC thermograms show that sulphonation with H 2 SO 4 decreases the Tg value, while CH 3 COOSO 3 H increases the transition, in comparison with the neat PS-AA. The latter could be due to the presence of ionic interactions in the copolymer. Side reactions during sulphonation of polymers are very important for the final physical properties. [ABSTRACT FROM AUTHOR]

The butadiene units of polystyrene-block-polybutadiene-block-polystyrene (SBS) triblock copolymer were subjected to epoxidation and subsequent sulphonation in order to prepare proton conducting ionomer membrane. The products were characterized by different techniques such as atomic force microscopy, Fourier transform infrared (FTIR) spectroscopy and electron microscopy. A simple laboratory device was developed to carry out the tests on proton conductance ability of the prepared ionomer membrane. The experiments demonstrated that the prepared membrane excellently performed as proton conducting membrane. DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7174 BIBECHANA 9 (2013) 50-58

Abstract: A simple way was proposed to prepare reverse phase open tubular column (OTC) for capillary electrochromatography (CEC) by dynamically coating cationic latex particles with C10 functional groups onto the fused silica capillary with surface sulphonation. The latex particles are bounded into the capillary wall via electrostatic attraction force and demonstrate good stability under test conditions. Relative bare silica capillary, reverse electroosmotic flow (EOF) is generated for the OTC due to the existence of cationic latex particles onto the capillary. Preliminary separation of aromatic compounds on an OTC with 50 i.d. has been demonstrated. [Copyright &y& Elsevier]

Summary: Conducting polymer films were prepared by introducing ionic groups via chemical modification of one of the blocks of the polystyrene- block-polybutadiene- block-polystyrene (SBS) triblock copolymer and by adding different amount of metal salts into the modified block copolymer. The butadiene part of the copolymer was partially sulphonated to prepare the proton conducting film while the epoxidized form was used to fabricate electron conducting films with different inorganic salts. The products were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and potential as well as conductivity measurements. [ABSTRACT FROM AUTHOR]

Abstract: Sulphonated polystyrene butadiene rubber/carbon nanoballs (SPSBR/CNBs) composites proton exchange membrane was developed by sulphonation of polystyrene butadiene rubber using chlorosulphonic acid as the sulphonating agent. The sulphonated rubber was then blended with non-catalytic carbon nanoballs (CNBs) produced by swirled floating catalytic chemical fluid deposition (SFCCVD) method. The SPSBR/CNBs composites proton exchange membrane was characterized to determine the thermal stability, water uptake, porosity and proton conductivity. The results obtained revealed that blending of the membrane with CNBs improved the thermal stability, water uptake retention and proton conductivity of the membrane with about 50% increase in proton conductivity. The synthesized and composite membranes were sandwiched between two electrodes to produce a membrane electrode assembly (MEA). The performance of the fabricated MEA was tested in a single PEM fuel cell using hydrogen as the fuel gas and oxygen as oxidant .The results obtained revealed that the utilization of SPSBR-CNBs composite proton exchange membrane resulted in higher performance compared to Nafion 112. Nafion 112 produced a maximum power density of 66.9 mW/cm2, while the developed membrane gave a maximum power density in the range of 73.7-97.1 mW/cm2depending on the mass of CNBs. [Copyright &y& Elsevier]

Abstract: Novel main-chain-type and side-chain-type sulphonated poly(ether ether ketone)s (MS-SPEEKs) are synthesised by reacting the sulphonic acid groups of pristine SPEEKs with 2-aminoethanesulphonic acid to improve the nano-phase separated morphology of the material. 1H NMR and FT-IR spectroscopy are employed to determine the structure and composition of main-chain-type and side-chain-type sulphonated polymers. Flexible and tough membranes with reasonable thermal properties are obtained. The MS-SPEEKs show good hydrolytic stability, and water uptake values ranging from 15% to 30% are observed. Compared to Nafion 117®, the methanol permeability of the MS-SPEEKs is dramatically reduced to 8.83×10−8 cm2 s−1 to 3.31×10−7 cm2 s−1. The proton conductivity increases with increasing temperature, reaching 0.013–0.182Scm−1. A maximum power density and open circuit voltage of 115mWcm−2 and 0.830V are obtained at 80°C, respectively, which is significantly greater than the values generated with Nafion 117®. The introduction of pendent side-chain-type sulphonic acid groups increases the single-cell performance by more than approximately 20%; thus, the lower water diffusivity, methanol permeability, electro-osmotic drag coefficient and high cell performance indicated that MS-SPEEK is a promising candidate for DMFC applications. [Copyright &y& Elsevier]

Protons conducting sulphonated polystyrene ethylene butylene polystyrene (SPSEBS) membranes and solution interaction technique for fuel cell applications. Various composite membranes based on sulphonated polystyrene ethylene butylene polystyrene ionomer with montmorillonite were prepared to increase the mechanical strength as well as decrease the methanol permeability. Possible interaction between MMT and SPSEBS was studied by IR and XRD. The suitability of the composite membranes for fuel cell application was evaluated in terms of water uptake, Ion exchange capacity, methanol permeability and proton conductivity. The methanol absorption and permeability of the composite membranes was found to decrease with the increase in MMT content. The proton conductivity of the membranes was studied as a function of ion exchange capacity. The proton conductivity of the membrane was found to decrease slightly from that of SPSEBS membrane. The negative impact of Montmorillonite on the ionic conductivity was restricted. Hence, the low cost composite membranes can be considered for use in Fuel Cell Applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag decorated & sulphonate functionalized quantum dot photocatalyst was fabricated. • Executed lactic acid esterification using fabricated photocatalyst at low temp. • Reaction parameters were optimized for maximized conversion. • LHHW model gives the best suitable kinetic model. • Reaction mechanism proposed using Spectroscopic and Photoelectrochemical analysis. Lactic acid, or 2-hydroxypropionic acid (CAS 50-21-5), a natural organic acid immensely engaged in agricultural industry, pharmacy, garment and chemical industry with a long history of practice. Lactic acid generated in fermentation necessitates an extra purification step that must be cost-effective. A green and energy derivatization of lactic acid into corresponding esters was carried out under photocatalytic conditions in this study to render them volatile for distillation separation. Esterification reaction was carried out under low energy photocatalytic system under solvent free conditions using a range of Zirconium impregnated-activated Titanium dioxide photocatalysts (1-0.005Ag/1.9-4.4%S-2.5-12.5%Zr@TO). Both physical and chemical events in the reaction grid have been studied and thermodynamic and kinetic parameters have been established expending pseudo-homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Haugen-Watson (LHHW) models and the different adsorption of components were proposed to fit the intrinsic kinetic data. Reaction mechanism for the process have been proposed based on the kinetic modelling results as well as FT-IR, TGA, Ammonia-TPD and photo-Electrochemical characterizations, as well as radical trapping tests, were also used to effectively support the reaction mechanism. The findings will be beneficial in the design of industrial photo-reactors for low temperature ester synthesis strategies. [ABSTRACT FROM AUTHOR]

A series of phthalocyanines were prepared from phthalodinitrile and corresponding metal salts by means of the ‘solvent’ methods. Some experiments were also conducted in the absence of a solvent in a ‘solvent-free’ process from phthalanhydride, urea and metal chlorides. All of the prepared phthalocyanines were modified by the incorporation of desirable functional groups in order to transform the virtually insoluble phthalocyanine skeleton into more soluble forms. Derivatives soluble in polar media were prepared by means of sulphonation, while those soluble in non-polar media were produced by chlorosulphonation with the subsequent condensation of prepared sulphochlorides with primary alkyl amines. [ABSTRACT FROM AUTHOR]