Spherical Gel Research Articles

Improvement of Adsorption Capacity by Refined Encapsulating Method of Activated Carbon into the Hollow-Type Spherical Bacterial Cellulose Gels for Oral Absorbent

To reduce the risk of adsorption of granular activated carbon (AC) in the gastrointestinal tract, we successfully prepared a hollow-type spherical bacterial cellulose gel encapsulated with AC (ACEG) and evaluated its pH tolerance and adsorption capacity. The bacterial cellulose gel membrane of ACEG features a three-dimensional mesh structure of cellulose fibers, allowing the selective permeation of substances based on their size. In this study, the preparation method of ACEGs was investigated, and the indole saturation adsorption capacity of the obtained gel was measured. We modified the gel culture nucleus gel from calcium alginate gel to agar gel, facilitating the encapsulation of previously challenging particles. The new preparation method used sodium hydroxide solution for sterilization and dissolution to remove the debris of Komagataeibacter xylinus, which was feared to remain in the bacterial cellulose membrane. This treatment was also confirmed to have no effect on the adsorption capacity of the AC powder. Therefore, this new preparation method is expected not only to improve the performance of ACEGs but also to be applied to a wide range of adsorbent-encapsulated hollow-type bacterial cellulose gels.

An improved synthesis of alkyl AMP esters

Enzymes belonging to the Acyl-CoA/NRPS/Luciferase (ANL) superfamily of enzymes, are significant targets in drug development. One member of this superfamily is Acetyl-CoA Synthetase (ACS). This enzyme is an emerging target for the treatment of various infectious diseases and cancer. Alkyl AMP esters have emerged as potent inhibitors of ACS. Previous methods for synthesizing these esters often involved water-based reactions or necessitate purification through reverse phase prep-HPLC or ion-exchange chromatography. To address these challenges, we developed a new approach utilizing 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) to couple 5′-adenylic acid to the corresponding alcohol, utilizing triethylamine as the base. This method yielded primary, secondary, unsaturated, and cyclic alcohols in excellent yields. Importantly, we optimized the reaction conditions to achieve excellent yield and purity without the need for reverse phase prep-HPLC or ion exchange chromatography. Instead, purification was achieved through silica gel chromatography using Biotage ® Sfar spherical silica gel.

Exploring performance and mechanism of modified metal-organic frameworks in calcium alginate/polyvinyl alcohol double-network hydrogels for effective dye wastewater treatment

To address the growing problem of dye wastewater pollution, a novel MOFs adsorbent calcium alginate/polyvinyl alcohol@UiO-66 was developed using environmentally friendly polymers, sodium alginate and polyvinyl alcohol creating gel spheres with a double-network structure through cross-linking. UiO-66 metal-organic frameworks are then grown onto the gel spheres, resulting in the final CA/PVA@UiO-66 adsorbent. This adsorbent boasts a high surface area (17.4 m2/g) and a mesoporous-nested microporous structure. It effectively removes MB from water, the actual maximum adsorption capacity was measured at 275.8 mg/g, which surpasses most existing adsorbents. Remarkably, the adsorbent retains 93.9 % of its initial capacity even after 10 reuse cycles. The adsorption process adhered to the Redlich-Peterson model and the PFO model. The N2-Sorption isotherm, actual Methylene blue (MB) adsorption experiments, and model analysis further suggest that the adsorption process is a complex heterogeneous diffusion process involving simultaneous chemical and physical adsorption. Additionally, the adsorption process is endothermic, indicating that it can occur spontaneously at 298 K. Increasing the temperature promotes the forward progress of the adsorption reaction, thereby enhancing the adsorption capacity. The gel adsorbent exhibited excellent dye wastewater purification capabilities, coupled with commendable reusability.

Effects of Particle Size and Shape on the Texture Property of a Solid-Liquid Dispersion System With Gel Particles.

Food texture is one of the most important factors for assessing the quality and acceptability of food. However, the study of food texture has been delayed compared with other factors, such as flavor and taste, due to the difficulty of quantitative analysis related to real physiological senses. Furthermore, the numerical and systematic evaluation of the texture property of dispersion systems, in which solid particles are dispersed in a liquid medium, is very difficult, despite most foods being in a solid-liquid dispersion state during mastication in the human mouth. In this study, the texture property of a solid-liquid dispersion system with spherical and cubic gel particles of agar and konjac was examined to evaluate the physical behavior of food during mastication using the back extrusion method. The yield stress of the system strongly depended on the size and shape of the particles, the mixing ratio of particles of different sizes and shapes, and the concentration of components in the particles. The proposed index, reflecting the size, shape, and number of particles and the yield stress of a single particle, expressed well the measured yield stress of the entire dispersion system. However, the adhesiveness and recoverability showed relatively little dependence on particle size. The findings obtained in this study will contribute to elucidating the texture property of various foods and to the development of new and novel food products and cuisines, thereby benefiting food science and industry.

Synthesis and characterization of pH-responsive sodium alginate/humic acid composite hydrogels for sustained drug release of l-ascorbic acid

Addressing the challenges of poor biocompatibility and degradability of artificial drug carriers and poor stability of natural monomer gels in the current pharmaceutical market, this study utilized green natural sodium alginate (SA) and humic acid (HA) as raw materials. SA/HA-Ca2+ hydrogel spheres were prepared using Ca2+ as a crosslinking agent and loaded with l-ascorbic acid (L-AA), and the drug-retardation study was conducted using the droplet method. Various analysis techniques confirmed the formation of a three-dimensional network structure through coordination between HA, SA, and Ca2+, resulting in hydrogel spheres with good thermal stability. Meanwhile, the drug-loading rate, swelling, and in vitro drug release of SA/HA-Ca2+ gel spheres were investigated. Results showed that the hydrogel spheres exhibited strong pH responsiveness and satisfactory pore structure favorable for the loading of L-AA. The solubility of the SA/HA-Ca2+ hydrogel in buffer solutions at pH = 1.4 and 7.4 was 1.7315 and 5.1235 g/g, respectively, while the swelling kinetics followed a second-order swelling kinetic equation; the maximum release of L-AA was 23.67 % and 82.64 %. The release profiles of L-AA from different drug-loaded gels conformed to Langmuir's quasi-primary and quasi-secondary kinetic models. In conclusion, this study provides a theoretical basis for achieving slow drug release using SA/HA-Ca2+.

Design, synthesis, and characterization of novel copolymer gel particles for water-plugging applications

Abstract Multi-stage plugging represents a promising strategy for enhancing production and injection rates in medium-and low-permeability oilfields. Despite its potential, the efficacy of current plugging agents, particularly hydrophobically bonded water-soluble polyacrylamide-based gel microspheres, is hindered by notable drawbacks such as low stability and inadequate compressive strength. Therefore, a comprehensive understanding of water plugging mechanisms coupled with the optimization of gel microsphere properties is essential for advancing the development of gel-based plugging agents with superior characteristics or intelligent regulatory capabilities. The P(AA-AM-[PrSO3]Vim) ionic liquid copolymerized gel particles were designed and synthesized by using microfluidic technique and titration gel method with AM, acrylic acid (AA), 1-vinylimidazole (Vim) and 1,3-propylsulfonyl lactone (PrSO3) as the raw materials. The morphology and structure of the copolymer gel particles were characterized, and the effects of [PrSO3]Vim and cross-linker content on the water-absorbing properties and strength of the gel particles were investigated. When the amount of [PrSO3]Vim was 12%, the concentration of crosslinker was 1.5%, and the temperature was 40°C, the water absorption capacity reached the maximum value of 163 g·g−1. The strength of the P(AA–AM–[PrSO3]Vim) spherical gel particles was maximized at a [PrSO3]Vim content of 4%. Furthermore, the chemical and physical roles of the P(AA–AM–[PrSO3]Vim) spherical gel particles were studied in a typical water-plugging environment. This study provides experimental data and a theoretical basis for the application of functional spherical gel-plugging particles in current oilfield environments.

The insight into behavior and mechanism of chitosan-embedded hydroxyapatite gel spheres used for efficient solidification of uranium in wastewater

In this work, hydroxyapatite (HAP), an environmentally friendly material was prepared with Phosphogypsum (PG) as calcium source, and uranium immobilization gel spheres were prepared by chitosan (CS) embedding, which would reduce HAP agglomeration while providing an abundance of uranium-loving groups, realizing “treating waste for waste”. The optimum pH for U(VI) removal was determined to be 4, the optimum dosage was 0.2 g/L, and qmax = 350.88 mg/g through batch experiments. When C0 = 10 mg/L, it was found that the removal rate of U(VI) by HAP-CS could be up to 99.92 %, and the residual uranium concentration was 0.008 mg/L, which meets the national emission standard. The removal rate of uranium can reach 95.92 % by applying it to high concentration uranium ore wastewater. CS was found to have good biocompatibility with HAP by SEM, FTIR, XRD, and XPS characterization. Meanwhile, we found that Ca, –OH, and P-O play a dominant role in the uranium removal process, and the main mechanism of uranium removal by Hydroxyapatite-Chitosan gel spheres (HAP-CS) is surface complexation, ion exchange, and dissolution–precipitation binding. The HAP-CS has high uranium removal efficiency, simple solid–liquid separation, and good biocompatibility, and can be used to treat actual uranium-containing wastewater.

Encapsulation of HRP-Immobilized Silica Particles into Hollow-Type Spherical Bacterial Cellulose Gel: A Novel Approach for Enzyme Reactions within Cellulose Gel Capsules.

We revealed that the encapsulation of enzyme-immobilized silica particles in hollow-type spherical bacterial cellulose (HSBC) gels enables the use of the inside of HSBC gels as a reaction field. The encapsulation of horseradish peroxidase (HRP)-immobilized silica particles (Si-HRPs, particle size: 40-50 μm) within HSBC gels was performed by using a BC gelatinous membrane produced at the interface between Komagataeibacter xylinus suspension attached onto an alginate gel containing Si-HRPs and silicone oil. After the biosynthesis of the BC gelatinous membrane, formed from cellulose nanofiber networks, the alginate gel was removed via immersion in a phosphate-buffered solution. Si-HRP encapsulated HSBC gels were reproducibly produced using our method with a yield of over 90%. The pore size of the network structure of the BC gelatinous membrane was less than 1 μm, which is significantly smaller than the encapsulated Si-HRPs. Consequently, the encapsulated Si-HRPs could neither pass through the BC gelatinous membrane nor leak from the interior cavity of the HSBC gel. The activity of the encapsulated HRPs was detected using the 3,3',5,5'-tetramethylbenzidine (TMB)-H2O2 system, demonstrating that this method can encapsulate the enzyme without inactivation. Since HSBC gels are composed of a network structure of biocompatible cellulose nanofibers, immune cells cannot enter the hollow interior, thus, the enzyme-immobilized particles encapsulated inside the HSBC gel are protected from immune-cell attacks. The encapsulation technique demonstrated in this study is expected to facilitate the delivery of enzymes and catalysts that are not originally present in the in vivo environment.

Efficient removal of direct dyes by SA-Er biopolymer gel spheres: Equilibrium isotherms, kinetics and regeneration performance study

Biomass-based adsorbent materials are characterized by their low cost, environmental friendliness, and ease of design and operation. In this study, biomass-based hydrogel microspheres erbium alginate (SA/Er) with high stability and adsorption properties were prepared by a one-step synthesis method. The prepared materials were characterized and analyzed by SEM-EDS, XRD, TGA, FT-IR, UV–Vis, BET-BJH and XPS, and the adsorption performance of SA/Er was investigated for high concentrations of azo dyes in water. The results showed that the adsorption performance of SA/Er on the azo dyes of direct violet N (DV 1) and direct dark green NB (DG 6) with concentrations of 850 mg/L and 1100 mg/L under the optimal conditions was very high, and the adsorption amount could be up to 692 mg/g and 864 mg/g, respectively. The adsorption process was in accordance with the quasi-secondary kinetic model, which was accomplished by physical and chemical adsorption; the Langmuir isothermal model was able to better respond to the adsorption equilibrium, and the adsorption was dominated by the adsorption of surface monolayers; after seven desorption cycles, the removal of both azo dyes by the adsorbent material could reach >79.7 %. Combined with the results of FT-IR, UV–vis and XPS analysis before and after the adsorption, it was revealed that the adsorption of SA/Er with the dye molecules mainly consisted of hydrogen bonding, electrostatic adsorption and surface complexation, which resulted in the significant adsorption effect on the two azo dyes, and the above results can provide a reference for the treatment of dye wastewater.

Sustainable soil rehabilitation with multiple network structures of layered double hydroxide beads: Immobilization of heavy metals, fertilizer release, and water retention

The remediation of heavy metal-contaminated soils necessitated a holistic approach that encompassed water and fertilizer conservation alongside soil property restoration. This study introduced the synthesis of (poly)acrylamide-layered double hydroxide gel spheres (PAM-LDH beads), which were designed to simultaneously immobilize heavy metals, control the release of fertilizers, and enhance soil water retention. Laboratory soil experiments under diverse conditions highlighted the superior performance of PAM-LDH beads in the immobilization of hexavalent chromium (Cr(VI)). The layered double hydroxide (LDH) component was identified as the key player in Cr(VI) immobilization, with anion exchange being the predominant mechanism. Notably, the encapsulated urea within the beads was released independently of environmental influences, governed by a concentration gradient across the beads surface. This release process was characterized by an initial phase of absorptive swelling followed by a diffusive phase. The impact on plant growth was assessed, revealing that PAM-LDH beads significantly curtailed Cr(VI) accumulation and alleviated its phytotoxic effects. Changes in the carbon (C) and nitrogen (N) content of the plants suggested that the urea encapsulated within the beads served as a nutrient source, contributing to soil fertility. Moreover, the water-holding capacity and soil-water characteristic curves of PAM-LDH beads suggested that these superabsorbent beads could delay soil water evaporation. The observed shifts in microbial community structure provided evidence for the enhancement of soil carbon and nitrogen cycles, indicative of improved soil properties.

Facile Wet‐Process to Free‐Standing Whispering Gallery Mode Resonators Mixed with Spherical Silica Gel and π‐Conjugated Molecules

Facile Wet‐Process to Free‐Standing Whispering Gallery Mode Resonators Mixed with Spherical Silica Gel and π‐Conjugated Molecules

Engineering and microstructural properties of environmentally friendly alkali-activated composites containing clinker aggregate: heat-curing regime and elevated-temperature effect

The common wisdom in the literature about clinker aggregate (CA) is that it improves the performance properties of mortar or concrete to some extent. The current study, in this context, investigated the physical characteristics and mechanical performances of alkali-activated composites (AACs) made entirely with CA. The CA was used in three particle sizes of 0–2 mm (named No.10), 2–4 mm (named No.5), and 4–8 mm (named medium). To examine the impact of the fine CA-size fraction on the characteristics of AAC, No.10 CA was partially replaced by No.5 CA up to 50%, while the content of the medium CA was kept constant in all AAC mixtures. Moreover, to evaluate the influence of the 8-h curing temperature on the performance of the AACs, different temperature-based curing strategies (ambient, 45, and 75 °C) were applied to the AACs. In the production of AACs, granulated blast furnace slag was employed as an aluminosilicate-rich raw material, and a sodium silicate and sodium hydroxide combination was used as an alkaline activator. Physical properties (flowability, water absorption, capillary water absorption, and dry unit weight), and 8-h strength performances (flexural and compressive) were determined. Furthermore, to monitor the influence of high temperatures on the characteristics of the AAC, the mixtures were exposed to elevated temperatures (200, 500, and 800 °C). In SEM image analysis, it was determined that spherical CSH gels were formed in the heat-cured AACs. It has been observed that the geopolymerization products decompose in AACs exposed to 800 °C. To evaluate statistically the experimental results, a multi-factor analysis of variance (ANOVA) was also applied. The results revealed that increasing the coarser fine aggregate fraction led to higher water absorption and apparent porosity capacities and lower unit weight. Besides, strength performance was improved by applying a heat-curing strategy to the AAC, whereas a decrease was observed by increasing the No.5 CA fraction. There was a remarkable reduction in compressive strength and considerable loss of mass when the AAC mixes were exposed to high temperatures.

Preparation and Screening of SRB Gel Particles Used for Deep Purification of Acid Mine Drainage.

The progressive decline of the coal industry necessitates the development of effective treatment solutions for acid mine drainage (AMD), which is characterized by high acidity and elevated concentrations of heavy metals. This study proposes an innovative approach leveraging sulfate-reducing bacteria (SRB) acclimated to contaminated anaerobic environments. The research focused on elucidating the physiological characteristics and optimal growth conditions of SRB, particularly in relation to the pH level and temperature. The experimental findings reveal that the SRB exhibited a sulfate removal rate of 88.86% at an optimal temperature of 30 °C. Additionally, SRB gel particles were formulated using sodium alginate (SA) and carboxymethyl cellulose (CMC), and their performance was assessed under specific conditions (pH = 6, C/S = 1.5, T = 30 °C, CMC = 4.5%, BSNa = 0.4 mol/L, and cross-linking time = 9 h). Under these conditions, the SRB gel particles demonstrated an enhanced sulfate removal efficiency of 91.6%. Thermal analysis via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) provided further insights into the stability and properties of the SRB gel spheres. The findings underscore the potential of SRB-based bioremediation as a sustainable and efficient method for AMD treatment, offering a novel and environmentally friendly solution to mitigating the adverse effects of environmental contamination.

Silica Gel Chromatographic Methods for Identification, Isolation and Purification of Gossypol Acetic Acid.

Several cottonseed varieties are cultivated in different countries. Each variety produces a different amount of gossypol as a natural toxic compound. The rising interest in cottonseed products (oil and feed) increases the demand for establishing simple methods for gossypol detection. Silica gel-based methods are ideal for its isolation, purification, and characterization. Silica gel-based methods are variants and can be used as simple methods for tracking plants' compounds. In this study, gossypol was isolated, characterized, and purified as gossypol acetic acid in the form of yellow crystals. Methods used for its characterization were TLC, preparative TLC, silica gel column, UV/IR spectrophotometer, and HPLC (robust spherical silica gel). A comparative study between its amount in both the Egyptian and Chinese varieties was performed. Under the experimental conditions, the Egyptian's cottonseed contains 8.705 gm/kg, while the Chinese's cottonseed contains 5.395 gm/kg. The TLC used in this study proved to be fast, accurate, and inexpensive. It can be used for gossypol acetic acid evaluation and quantification. Additionally, using TLC as a pre-purification step will give a pre-judgment for the sample's purity and quality. This step will protect the expensive HPLC silica gel-based column from any unexpected impurities. During each step, the silica gel itself could be simply removed by paper filtration. Collectively, the different silica gel-based methods as well as the other used methods are recommended for better Gossypol acetic acid isolation, purification, and characterization, as well as for maintaining HPLC columns.

Adsorption Capacity of Activated Carbon-Encapsulated Hollow-Type Spherical Bacterial Cellulose Gels for Uremic Toxins in a Simulated Human Gastrointestinal Environment.

To reduce the risk of the adsorption of granular activated carbon in the gastrointestinal tract, we successfully produced a hollow-type spherical bacterial cellulose (HSBC) gel containing activated carbon with a particle size of 6 μm. In this study, the aim of which was to develop an effective formulation, we evaluated the stability of activated-carbon-encapsulating HSBC gels under various pH conditions. Activated-carbon-encapsulating HSBC gels (ACEGs) retained the activated carbon without leaking when subjected to agitation in acidic or basic environments. The saturated adsorption amount, calculated using the Langmuir adsorption isotherm, was affected by the target adsorbate and pH conditions. These results indicate that ACEGs can adsorb uremic toxins and their precursors similarly to conventional uremic toxin adsorbents while preventing direct contact between the encapsulated activated carbon and the gastrointestinal tract. Compared to powdered activated carbon, the ACEG is less likely to be adsorbed in the gastrointestinal tract. Therefore, the proposed ACEG is a promising new formulation that will contribute to the treatment of renal failure and improve patients' compliance with medication.

Role of polyferric sulphate in hydration regulation of phosphogypsum-based excess-sulphate slag cement: A multiscale investigation

Current demand for waste recycling, phosphogypsum-based excess-sulphate slag cement (PESSC) as a sustainable cement prepared by solid wastes, urges enhancing its performance development based on microstructure optimisation. For the purpose of improving the performance and durability of PESSC used in normal or corrosive environments, it is deemed an efficient technique to produce iron-doped compounds with high thermodynamic stability. This paper presents a systematic study of the effect of iron modification on PESSC binders by introducing 0%–2% polyferric sulphate (PFS) from a multiscale viewpoint. XPS, 29Si and 27Al NMR, and TEM were used to characterise the nanostructure of solid particles firstly at Level I. Then, the chemical composition and phase assemblage of PESSC binders were revealed at Level II in terms of ICC, ICP, DTG-DSC, FTIR, BSE-EDS and XRD. Finally, setting time and strength development were determined at Level III. Results indicated that the soluble FeOH4− supplied by the hydrolysis of PFS promotes the generation of iron-doped ettringite with a greater length-to-diameter ratio and thermodynamic stability. Seeding effect of iron doping also promotes the production of spherical and retiform gels with a slight influence on the chemical components and polymerisation. Despite the fact that iron doping weakens the early strength of PESSC mortars, it promotes the persistent hydration rate by retarding precipitation and encapsulation of hydrates on the surface of the slag, showing excellent strength in the later stages. In view of microstructure evolution and performance development during each stage, PFS supplementation within 1.0% is considered a feasible modification of PESSC relying on the formation control of iron-doped hydrates.

Sodium alginate/gelatin hydrogel spheres loaded with Fructus Ligustri Lucidi essential oil: Preparation, characterization and biological activity

The application of plant essential oils in the food industry is often hindered by their poor water solubility and high volatilize. Encapsulation has emerged as an effective solution to this problem. This study focuses on the preparation of Fructus Ligustri Lucidi essential oil gel spheres (FEOH) based sodium alginate and gelatin. The optimum formulation for FEOH was established by Box-Behnken Design response surface testing, resulting in a composition of 10 % FEO, 5 % TW20 and 2 % CaCl2. This formulation achieved an encapsulation efficiency of 85.56 %. FTIR and SEM results indicated the successful encapsulation of FEO within the gel spheres. Furthermore, DSC and TGA results showed that encapsulation enhanced the thermal stability of the essential oil. At room temperature, the water content of FEOH exceeded 90 %, and it showed the highest swelling ratio of 62.5 % in an alkaline medium at different pH conditions. The in vitro release behavior showed that FEOH was released up to 85.28 % in oil-based food simulants within 2 h. FEOH showed strong antibacterial activity, with a Minimum Inhibitory Concentration (MIC) of 128 mg/mL against Staphylococcus aureus and 256 mg/mL against Escherichia coli. The gel spheres obtained in this research show significant potential as food preservatives in food matrices.

Adsorption studies of tetracycline hydrochloride and diclofenac sodium on NH2-MIL-53(Al/Zr) sodium alginate gel spheres

Metal-organic frameworks are emerging inorganic-organic hybrid materials that can be self-assembled from metal ions and organic ligands via coordination bonds. These materials possess large specific surface area, tunable pore structure, abundant active center, diversity of functional groups as well as high mechanical and thermal stability which promote their applications in adsorption and catalysis studies. In this study, NH2-MIL-53(Al/Zr) was prepared and embedded into sodium alginate gel spheres (NH2-MIL-53(Al/Zr)-SA) and its adsorption properties towards TC and DCF in solution were investigated. According to XRD and FTIR analysis, the structure of the raw material was not changed after making the gel spheres. The maximum adsorption towards TC (pH =3) and DCF (pH =5) reached 98.5 mg·g−1 and 192 mg·g−1, respectively. The process was consistent with Langmuir and Freundlich, suggesting that there was both monolayer and multilayer adsorption which infers the presence of physical adsorption (intra-particle diffusion) and non-homogeneous chemical adsorption. The thermodynamic parameters showed that the adsorption process was a spontaneous entropy increasing reaction. The regeneration rate of spent NH2-MIL-53(Al/Zr)-SA could still reach 99.1 % after three cycles, indicating good regeneration performance. This study can provide a basis for the application of NH2-MIL-53(Al/Zr)-SA in wastewater treatment.

Environmentally friendly zero-valent iron-modified biochar beads for high-performance antimonite removal from aqueous solution

Antimony (Sb) contamination in aquatic environments has emerged as a significant environmental concern because of extensive industrial activities involving Sb and its associated health hazards. Nano-zero-valent iron (nFe) is recognised for its efficacy in heavy metal remediation; however, its application is often hindered by poor dispersion and suboptimal adsorption properties. We designed an innovative approach in which nFe is calcined with biochar to mitigate agglomeration and subsequently amalgamated with sodium alginate to form composite gel spheres (PEI/SA/BCFe) in a calcium chloride solution. The ability of these gel spheres to remove antimonite (Sb(III)) from water was evaluated under various conditions, including pH, initial concentration, the presence of competing ions, temperature, and cycling experiments. The R2 fitted to the Langmuir isotherm were 0.99, 0.96 and 0.97, respectively. The adsorption was carried out under thermostatic shaking conditions, and the maximum adsorption capacity was 621.04 mg g−1, 509.34 mg g−1, and 373.10 mg g−1 at 10, 25, and 40 °C, respectively, which corresponded to removal efficiencies of 72.5%, 65.3% and 63.7%, respectively. The underlying mechanisms driving the adsorption process were primarily attributed to the oxidation of Sb(III), inner-sphere complexation, and coprecipitation. This comprehensive study not only highlights the potential of PEI/SA/BCFe as an effective solution for mitigating antinomy contamination in water but also contributes valuable insights into the mechanistic aspects of heavy metal adsorption.

Exploring drug release performance of hollow‐structured CS/SA/POSS composite gel spheres employing hydrophilic polymerizable AS‐POSS as crosslinker

AbstractThis study prepares a series of hollow‐structured CS/SA/POSS composite gel spheres with a diameter of ~2.5 mm by using hydrophilic Janus‐type polyhedral oligomeric silsesquioxane (AS‐POSS) as a crosslinking agent in combination with sodium alginate and chitosan via electrostatic adsorption/free radical polymerization. As the content of POSS increases, the wall thickness of the gel spheres also increases from 20 to 30 μm, leading to a more compact and smooth wall structure in the polymerized CS/SA/POSS composite gel spheres. Additionally, the introduction and polymerization of POSS significantly enhance the stability, drug loading rate, and entrapment rate of the gel spheres, providing them with improved drug release capabilities. For hydrophilic drug doxorubicin, the loading rate and encapsulation rate reach 41.2% and 79.9%, respectively, while for the hydrophobic drug ibuprofen, they are 14.7% and 76.3%. Compared to some previously reported drug‐loaded gel materials, the gels prepared in this study demonstrate relatively higher drug loading performance. Thus, these hollow‐structured CS/SA/POSS composite gel spheres hold promise as innovative drug carriers in the biomedical field.