Cationic Resin Research Articles

Efficient adsorptive removal of potassium from potassium perrhenate solution using a cationic ion exchange resin.

Potassium is a harmful impurity in the rhenium sinter, which adversely affects its mechanical properties by significantly reducing the density of sintered rhenium. Cationic resin is a promising material for potassium removal. In this study, the strong acid cationic exchange resin C160H was pretreated with an HNO3 solution to enhance its performance in potassium removal. The pretreated C160H resin was characterized using BET, SEM and point of zero charge (PZC) measurements to understand its physicochemical properties. It was verified that the lower PZC value of C160H than that of pristine C160 resin resulted in increased potassium adsorption efficiency. Moreover, the pretreated C160H resin exhibited a maximum potassium adsorption efficiency of 99.28% for 2.00 g L-1 KReO4 at 25 °C and pH 7.0 for 6 h, with a solid-to-liquid ratio of 1 : 20. The cation sequence affecting potassium adsorption efficiency was found to be Na+ < Ca2+ < Fe3+ < NH4 +. Isothermal adsorption thermodynamics showed that potassium adsorption by C160H resin followed a heterogeneous and exothermic process. The pseudo-second-order kinetics model best fitted the data, suggesting that potassium adsorption was primarily chemical in nature. DFT calculations confirmed that the adsorption mechanism was based on ion exchange between H+ and K+, with electrostatic interactions serving as the primary driving force for adsorption. The C160H resin demonstrated outstanding regeneration performance, maintaining an adsorption efficiency above 99% after ten cycles. These findings could contribute to improve the potassium adsorption capacity of the resin, thereby reducing both resin dosage and cost in the purification of perrhenate salts.

Optimizing seawater purification: Ion exchange selective demineralization through single and multi-objective techniques

This study focused on optimizing a selective demineralization process for seawater purification using ion-exchange technology. Experiments were conducted in three semi-batch reactors containing cation, anion, and mixed resins. Key process parameters included temperature (25 °C–50 °C), resin depth (23–82 cm), and pH (2–12). Statistical modeling and optimization were performed using Response Surface Methodology (RSM) with a central composite design, addressing both single and multi-objective criteria. A desirability function was used to assess process performance based on multiple response variables, such as the removal of trace metals (Ca2+, Mg2+, Mn2+, Zn2+, Fe2+, Cu2+, Ba2+, Cd2+), conductivity reduction, and total dissolved solids (TDS) elimination. Ten quadratic regression models were developed to describe the relationships between input parameters and responses, achieving high R2 values (≥0.7) for most responses except Cu2+, Mn2+, and Ba2+. Multi-objective optimization highlighted TDS, conductivity, and the removal of Ca2+, Mn2+, and Mg2+ as critical targets due to their significant impact on water hardness. The optimal conditions (temperature of 43.9 °C, resin depth of 75.45 cm, and pH of 5.9) yielded a composite desirability score of 0.77. Under these conditions, the process achieved over 99% removal efficiency for key cations (Ca2+, Mg2+), significant conductivity reduction, and near-complete TDS elimination. However, Mn2+ removal efficiency reached approximately 85%, likely due to its lower diffusion coefficient and higher hydration enthalpy. The results, particularly from the multicriteria optimization combined with desirability function approaches, highlight the effectiveness of ion-exchange resins in seawater demineralization and offer a robust framework for enhancing process performance.

Water efficiency analysis and optimization of chemical usage on productivity of demineralizer plant PT. Pupuk Iskandar Muda

Abstract A demineralization process is carried out in industrial water treatment, and this process requires large amounts of chemicals that can increase the pollutant load of wastewater and harm ecosystems, biodiversity, and climate. Therefore, this study aims to analyze water efficiency and chemicals used in the water treatment process at the Demineralizer Plant. The analysis was carried out through a fishbone diagram and Nominal Group Technique (NGT) method to identify the problem so that the corrective solution is obtained, namely by backwashing the cation and anion resins periodically at 100,000 m3, maintaining the flow service setting for the demineralized plant at 90 - 100 m3/hour, and adjusting the specific gravity at the time of regeneration of Cation in the first Chemical. The results showed that PT made improvements. Pupuk Iskandar Muda has succeeded in carrying out a water efficiency of 484.87 m3. That impacts production costs, which decrease along with reduced chemical use. The company saved IDR 4.251.782 in 2021 after the repairs were carried out. Water efficiency and optimization of chemical use can save the cost of purchasing chemicals, minimize environmental impacts, and provide the best and most practical solutions at PT. Pupuk Iskandar Muda.

Solvent-free Simplistic Synthesis of Bis(indolyl) Methanes Using Tulsion®- 8052 MP Resin

Tulsion®-8052 MP cation resin catalyst accelerates chemical reaction by creating a suitable environment for the aldehyde and indole reactants to interact and form desired product bis(indolyl) methanes in solvent-free room temperature conditions. The uniqueness of this catalytic method is that it is eco-friendly, recyclable, selective, and operates on a variety of functional groups with good to excellent yield at room temperature conditions without the use of any hazardous solvents, high temperature, and inert atmosphere.

A Systematic Study on Biobased Epoxy-Alcohol Networks: Highlighting the Advantage of Step-Growth Polyaddition over Chain-Growth Cationic Photopolymerization.

Vanillyl alcohol has emerged as a widely used building block for the development of biobased monomers. More specifically, the cationic (photo-)polymerization of the respective diglycidyl ether (DGEVA) is known to produce materials of outstanding thermomechanical performance. Generally, chain transfer agents (CTAs) are of interest in cationic resins not only because they lead to more homogeneous polymer networks but also because they strikingly improve the polymerization speed. Herein, the aim is to compare the cationic chain-growth photopolymerization with the thermally initiated anionic step-growth polymerization, with and without the addition of CTAs. Indeed, CTAs lead to faster polymerization reactions as well as the formation of more homogeneous networks, especially in the case of the thermal anionic step-growth polymerization. Resulting from curing above the TG of the respective anionic step-growth polymer, materials with outstanding tensile toughness (>5MJ cm-3) are obtained that result in the manufacture of potential shape-memory polymers.

Valorisation of acid mine drainage through effective recovery of selected rare earth elements using cationic resins

Acid mine drainage (AMD) presents a challenge to the environment if not well managed, but it also presents an opportunity for the recovery of economically valuable products, including rare earth elements (REEs), which are critical for the development of advanced, and green technologies. REE concentrations in AMD samples from coal and gold mines were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES) and their sorption by different cationic resins (CHT4083, CHP4502 and CHP00712) was evaluated. Optimum conditions for the sorption of the REEs by these resins were determined through batch experiments and desorption of the REEs from the resins using different concentrations of sulphuric acid (H2SO4) solutions. Coal mine drainage (CMD), with a low pH of 2.37, had higher amounts of REEs (ΣREE 226.3732 mg/L) than AMD from the gold mines (ΣREE 4.9705 mg/L), with a pH of 3.21. A REE sorption efficiency of up to 98% was obtained with CHP4502 and CHP00712 resins and further optimisation of CHP00712 revealed that a resin volume of 250 mL and a contact time of 10 min were required to successfully remove REEs from 500 mL AMD. The sorption capacities of the resin for the selected REEs were 3.88 mg/g, 0.88 mg/g, 1.37 mg/g, 3.18 mg/g, 0.67 mg/g, 0.01 mg/g and 0.27mg/g for Pr, Gd, Nd, Ce, Sm, Eu and Y, respectively. Elution of the resin with a 0.5 N solution of sulphuric acid desorbed the REEs. AMD from coal mines could be an alternate source of REEs and cationic resins can be used to recover these REEs from the CMD. Further investigations, including impregnation of resin to improve its sorption capacity, and temperature effects on the sorption process, are recommended.

Optimization of the polishing process by integrating experimental design and high-throughput screening

Complex bispecific antibody formats tend to form more product-related impurities than monoclonal antibodies. The primary constraints are yield and purity in the polishing stage. The purpose of this study was to enhance the understanding of the optimal working window for four mixed-mode resins and to reduce the burden of resin screening and parameter optimization during process development. This study optimized the loading and elution conditions of four different mixed-mode cationic resins to enhance the yield and purity by integrating Design of Experiments with High-Throughput Screening. It was observed that despite being weakly acidic mixed-mode cationic resins, these four resins exhibited significant differences in their adsorption and elution performances and varied tolerances to salt concentrations. Capto MMC demonstrated strong hydrophobicity, while the performance profiles of MX-Trp-650 M and Nuvia cPrime were similar, with Nuvia cPrime showing superior purification effects. Eshmuno CMX, by extending its side chain ligand, achieved higher binding efficiency and capacity. Through the optimization of salt concentrations or the application of dual-gradient elution strategies, the target protein with high yield (77 %) and purity over 99 % was successfully obtained. This research not only provides in-depth insights into the application of mixed-mode chromatography in the biopharmaceutical field but also offers practical optimization strategies for the industrial-scale purification of bispecific antibodies.

Solid-State NMR Characterization of Mefloquine Resinate Complexes Designed for Taste-Masking Pediatric Formulations.

Mefloquine (MQ) is an antimalarial medication prescribed to treat or malaria prevention.. When taken by children, vomiting usually occurs, and new doses of medication frequently need to be taken. So, developing pediatric medicines using taste-masked antimalarial drug complexes is mandatory for the success of mefloquine administration. The hypothesis that binding mefloquine to an ion-exchange resin (R) could circumvent the drug's bitter taste problem was proposed, and solid-state 13C cross-polarization magic angle spinning (CPMAS) NMR was able to follow MQ-R mixtures through chemical shift and relaxation measurements. The nature of MQ-R complex formation could then be determined. Impedimetric electronic tongue equipment also verified the resinate taste-masking efficiency in vitro. Variations in chemical shifts and structure dynamics measured by proton relaxation properties (e.g., T1ρH) were used as probes to follow the extension of mixing and specific interactions that would be present in MQ-R. A significant decrease in T1ρH values was observed for MQ carbons in MQ-R complexes, compared to the ones in MQ (from 100-200 ms in MQ to 20-50 ms in an MQ-R complex). The results evidenced that the cationic resin interacts strongly with mefloquine molecules in the formulation of a 1:1 ratio complex. Thus, 13C CPMAS NMR allowed the confirmation of the presence of a binding between mefloquine and polacrilin in the MQ-R formulation studied.

Modulation of cream cheese physicochemical and functional properties with ultrafiltration and calcium reduction

The production of cream cheese from ultrafiltered (UF) milk can reduce acid whey generation but the effect of altered protein and calcium concentration on the physicochemical properties of cream cheese is not well understood. In this study, the effect of skim milk concentration by UF (2.5 and 5 fold) was assessed both with and without calcium reduction using 2% (w/v) cation resin treatment. UF concentration increased the concentration of peptides and free amino acids and led to a more heterogeneous and porous microstructure, resulting in a softer, less viscous and less thermally stable cream cheese. Calcium reduction decreased peptide generation, increased the size of corpuscular structures, decreased porosity and increased thermal stability but did not significantly decrease cheese hardness or viscosity. The study illustrates how protein or calcium concentration, can be used to alter functional properties.

Enzyme activity test paper with high wet strength and anion adsorption properties fabricated from whole cationized softwood chemical fiber

Paper-based test film material is widely used in a variety of test instruments for different applications. The enzyme activity test paper sheet is one of the most popularly used test papers. Here we present a novel fabrication of paper-based enzyme activity test paper without cationic resin added in. The chemical pulping fibers were first beaten to different degrees (from 14.6 to 41.5°SR) with a PFI beater. After that, the fibers were modified with a cationic agent (3-chloro-2-hydroxypropyl trimethyl ammonium chloride) under the system of alkali and water solution. Finally, the test papers were made with the modified fiber by a regular paper former in lab. The results showed that beating is beneficial for the improvement of the cationization reaction which is indicated by the Zeta potential, FTIR and EDS. The main mechanisms involved are the destruction of crystalline zone, increase of free hydroxyl group and defibrillation. This hypothesis was supported by the SEM, XRD and fiber analyzer. Beating under the optimized condition, the wet strength and liquid absorbability of test paper can meet the application requirement, and the test results of enzyme activity are quite close to those of commercial test papers.

A contribution to understanding ion-exchange mechanisms for lithium recovery from industrial effluents of lithium-ion battery recycling operations

Industrial effluents or process waters generated from spent lithium-ion battery recycling operations often contain high concentrations of lithium ions (Li+). This study characterizes the composition of process water obtained from pre-treatment and concentration operations of LIBs recycling. Ion-exchange experiments are conducted using synthetic lithium solutions (1 g/L) and industrial waters to understand Li+ recovery. Employing four commercial cationic resins, fast Li+ exchange kinetics are observed fitting the pseudo-second order model. The equilibrium isotherm data corresponds to the Langmuir adsorption model and reveals a Li capacity of 30–32 mg/g using Amberlite™ IRC 120 H, 70 mg/g using Lewatit® TP 308 H, 37–40 mg/g using Lewatit® TP 208 Na, and 37–41 mg/g using Lewatit® TP 260 Na. While the resins initially demonstrate moderate affinity for Li+, this can be significantly enhanced by increasing the Li+ concentration. Notably, as LIBs recycling operation effluents typically contain minimal competing ions, these results underscore the potential of employing ion exchange as a viable method to recover and concentrate lithium before precipitation into lithium salts.

Effects of competitive cations and dissolved organic matter on ammonium exchange and up-concentration properties of ion exchangers from domestic wastewater under multicycle exchange - regeneration operation

This study aimed to investigate the impact of competitive cations and dissolved organic matter (DOM) on ammonium exchange and up-concentration properties of ion exchangers for domestic wastewater treatment during the multicycle exchange - regeneration operations. Three ion exchangers, including zeolite, strong acid cation resin and 4A molecular sieve (MS), all showed good NH4+ separation and up-concentration properties in 30 exchange - regeneration cycles. The exchange capacities of zeolite, resin, and MS decreased by 8.2 %, 10.4 %, and 4.8 % in the presence of Ca2+ and Mg2+, while DOM only impaired the exchange ability of zeolite. The up-concentration factors of zeolite, resin, and MS were 5.1, 11.5, and 5.0, respectively. Isothermal tests and breakthrough curves confirmed that long-term salt regeneration slightly reduced the exchange capacity, and the presence of competitive cations and DOM shortened the breakthrough time. Elemental mass balance further demonstrated that Ca2+ and Mg2+ were easily trapped by ion exchangers and could be released into the regeneration solution, which should be precipitated to avoid accumulation for long-term cyclic operation. Morphological analysis indicated that the presence of Ca2+ and Mg2+ would cause the resin to crack. Overall, for domestic wastewater treatment, the resin exhibited the highest NH4+ capture ability and up-concentration properties with low resistance to Ca2+ and Mg2+ contamination, while silicate exchangers with a regular and compact structure had higher durability but lower up-concentration properties.

Study on Organic Fluorine Modified Cationic Acrylic Resin and its Application in Cathodic Electrodeposition Coatings

The organic fluorine modified/containing cationic acrylic resin is prepared via solution polymerization technique using hexafluorobutyl methacrylate (HFMA) along with butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), dimethylaminoethyl methacrylate (DMAEMA) and hydroxy propyl methacrylate (HPMA) as the comonomers, proprylene glycol monomethyl ether (PGME) as the solvent, and 2, 2-Azo-bis-iso-butyronitrile (AIBN) as the initiator. The synthesized resin in which fluorine atom is introduced into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthesized resin and blocked isocyanate. The influence of the amount of organic fluorine on the resin and the resultant CED coatings is investigated in detail. In view of the appearance and hydrophobicity of the film, the optimum amount of organic fluorine is obtained, which is 12.0%. The hydrophobicity and the acid and alkaline resistance properties of the coating film are improved when the organic fluorine monomer is introduced into the resin.

Evaporation-free tandem-column separation for Sr from geological samples with high Rb/Sr ratios

A novel tandem column method was devised for effective purification of Sr from geological samples characterized by relatively high Rb/Sr ratios, employing a strategic sequence of columns of AG50-X12 cation resin, Chelex-100 chelating resin and AG50-X8 cation resin. The process initiates with the AG50-X12 column to remove most of the matrix elements, followed by the Chelex-100 column to remove the residual Rb under alkaline conditions despite its inability to adsorb alkali metals such as Na, K, and Rb. The Sr fraction was eluted directly into the Chelex-100 column from the AG50-X12 column by a NH3-NH4Cl solution. The final purification through the AG50-X8 column to eliminate residual NH4Cl ensures the effective removal of matrix elements (such as K, Na, Li, Ti, Al, Fe, Mg, Mn and Ca) and Rb. The Chelex-100 resin acts comparatively to a similar Sr-specific resin for Rb and Sr. This method proved its efficacy and precision by aligning the Sr isotopic ratios from a range of reference materials, (JR-1, JR-2, JB-2, BCR-2, BHVO-2, W-2, GSP-2, CRPG Mica-Mg, CRPG Mica-Fe and NIST SRM 987) with their published values, demonstrating its reliability for Sr isotope analysis in complex geological matrices.

Removal and recovery of phenolic compounds from OMW by a cationic resin

Olive mill wastewater (OMW) is rich in valuable compounds such as phenolic compounds. Amberlite@HPR1100 was applied as adsorbent to recover these added-value compounds from OMW. For synthetic OMW, Langmuir isotherm and pseudo-second order kinetic model were able to predict the experimental data instead for real effluent, were the Freundlich isotherm and the pseudo-first order kinetic model the best fits. The continuous process was also studied, for real OMW the tbp, tst and tex were 1.27 min, 84.4 min and 575 min, respectively. After 645 min of adsorption, 42 % of phenolic content was adsorbed into the resin. An industrial column for recovering phenolic compounds from OMW was designed, which should have around 5 m and 0.6 m of height and diameter, respectively, filled with 112 kg of resin (dry basis). The desorption process for real OMW with acetone 80 % recovery was accomplished after 5 h of contact.

SB‐2 cationic resin: an efficient and reusable organocatalyst for the synthesis of α‐aminophosphonates, DFT calculations and, computer aided design in antifungal activity

AbstractSB‐2 cationic resin has been employed as an unexpected and reusable heterogeneous organocatalyst in multicomponents reaction for the synthesis of the α‐aminophosphonates derivatives that act as antifungal agents, this reaction proceeds under eco‐friendly and simple procedure by condensation in one pot of substituted aromatic aldehydes, anilines and diethylphosphite. Excellent isolated product yields are obtained (up to 70 %) for (4 a–o) within shorter reaction times in solvent‐free condition. The synthesized compounds were determined by spectroscopic analyses such as: NMR (1H, 13C and 31P), IR and HRMS.Molecular geometries, electronic properties, stability and reactivity such as: HOMO/LUMO, , dipole moment (6.1308&lt;D&lt;10.5829), electronegativity (2.3490&lt;X&lt;3.5892), electrophilicity (1.1046&lt;ω&lt;3.2185) and the calculated thermodynamic descriptors (Zero‐point Energies, Enthalpy and Gibbs Free Energy) of four trimethoxy α‐aminophosphonates derivatives (4 j, 4 k, 4 l and 4 m) were carried by DFT at B3LYP 6‐31G (d, p) basis set. Computer aided design by molecular docking of studied compounds revealed a good binding energy against 5HS1 receptor to be considered as antifungal candidates and compared with Voriconazole. In additionally, druglikeness parameters of selected compounds were found through in silico pharmacological ADME/T properties estimation.

Potential Regulatory Gene Network Associated with the Ameliorative Effect of Oat Antibacterial Peptides on Rat Colitis.

Oat protein is unstable in intestinal fluid digestion, and it is easily degraded by trypsin and chymotrypsin, producing low molecular weight peptides. Endopeptidase hydrolysis can improve the bioavailability of active peptides and avoid further digestion in the gastrointestinal tract. Antimicrobial peptides (AMPs) can effectively improve host immunity, but most related studies focus on physiology and ecology, and there are few reports on their molecular level. Therefore, in this article, oat peptides were prepared via the simulated digestion method in vitro, and the main metabolites and action factors affecting colitis were screened by using the multi-omics methods in a high-throughput mode to analyze the effect and mechanism of colitis. Firstly, oat antimicrobial peptides were prepared from cationic resin combined with HPLC, and the anti-inflammatory effects of antimicrobial peptides were analyzed in vitro through the use of human colon epithelial (HCoEpiC) anti-inflammatory cells. In vivo experiments using rats have verified that AMPs can effectively prevent colitis caused by dextran sodium sulfate (DSS), reduce intestinal inflammatory cell infiltration and glandular disappearance in the colon, and reduce the apoptosis rate of colon cells. Secondly, metabolomics and transcriptomics were combined to analyze the mechanism of preventing enteritis, and it was found that oat antimicrobial peptides can promote DAG diglycerol production and inhibit the activation of T helper cells (TH), resulting in the down-regulation of key factors in the main downstream pathways of TH1, TH2 and TH17, and inhibit the production of inflammatory cells. At the same time, AMP can activate the wnt pathway, improve the expression of key genes of wnt and frizzled, promote the generation of intestinal stem cells, facilitate the differentiation and repair of intestinal epithelial cells, and prevent the generation of enteritis. Finally, the underlying genetic regulatory network of the important pathway was constructed from the effect of AMP on rat colitis.

Kinetics of microwave-assisted synthesis of ethyl hexanoate by using heterogeneous catalyst: process intensification and energy consumption analysis

The current work illustrates microwave-assisted synthesis of ethyl hexanoate without a solvent system using cationic resin (Amberlyst-15) as a catalyst. The effect of various parameters was evaluated, and a maximum equilibrium conversion of 84.2% was achieved in 50 min. The optimized parameters were 1:02 mole ratio of acid to alcohol, temperature 328 K, and 9% (w/w) catalyst loading. The impact of mole ratio and catalyst loading on the reaction rate was predicted by developing an empirical correlation. The activation energy was determined as 17.63 kJ/mol. The experimental data fitted well with Eley-Rideal mechanism, in which the surface reaction was a rate-limiting step. Thermodynamic parameters were evaluated, including standard enthalpy, Gibbs free energy, and reaction entropy. The energy consumption for microwave reaction was predicted as 15.357 × 105 kJ/kg. These results have been compared with that of conventional as well as ultrasound-assisted synthesis of ethyl hexanoate. This novel technique shows an enhancement in reaction rates and higher yields.

Purification of boron using a combination of cationic and boron-specific resins and determination of boron isotopic composition in sediments by MC-ICP-MS

Boron is a lithophilic and biophilic element. Boron isotopes in sediments provide insight in the Earth's history. Boron is purified by a combination of cationic and boron-specific resins, and the isotopic composition of boron in sediments can be determined with high accuracy by MC-ICP-MS.

Colloidal Silica Production with Resin from Sodium Silicate and Optimization of Process

Colloidal silica is a stable and homogeneously dispersed form of amorphous silicon dioxide (SiO2) nanoparticles in water. Colloidal silica has been the focus of research due to large surface area, biocompatibility, low toxicity and chemical and thermal stability. It has been used in a wide variety of industrial applications, including pulp and paper, chromatography, electronics, foods, and colloids, as well as in the ceramics and glass industry. In this study, colloidal silica was produced using cationic resin and sodium silicate and process conditions were optimized. Temperature (50-80 °C), mixing speed (200-500 rpm) and time (20-120 min.), which significantly affect the particle size, were selected as parameters. Particle size distribution (PSD) analyzes of colloidal silica particles were performed to determine appropriate levels of the parameters. The most suitable process conditions are 50°C temperature, 40 min. and 300 rpm. The average particle size of colloidal silica produced in optimum conditions was measured as 80 nm.