Glycol Diglycidyl Research Articles

Sustainable leather making — An amphoteric organic chrome-free tanning agents based on recycling waste leather

Currently, globally, 90 % of the tannery is still tanned by using chrome, resulting in chromium-containing wastewater and chromium-containing solid waste that will cause serious harm to the environment. Under the pressure of environmental protection, on the one hand, the leather manufacturing industry should to dispose the current problem of chromium pollution, especially chromium-containing solid waste (chromium-containing waste leather (CCWL)), on the other hand, to popularize chrome-free tanning agent. Organic chrome-free tanning agents are the way forward for chrome-free tanning agents. However, organic chrome-free tanning agents exhibit several limitations with respect to their preparation and applications: The preparation process is not eco-friendly, and physicochemical properties of tanned crust leather are poor. More importantly, the leather tanned by an organic chrome-free tanning agent has low absorptivity of traditional anionic wet finishing materials, resulting in high total dissolved solids in tannery wastewater, which increased the difficulty of tannery wastewater treatment, and posed a potential threat to the environment. In this study, collagen polypeptide (CP) was extracted by using in situ dechromization and industrial trypsin from CCWL, followed by modification with ethylene glycol diglycidyl ether (EGDE) to obtain an epoxy-terminated, biomass-based, amphoteric organic, chrome-free tanning agent (CP-EGDE) with a high isoelectric point of 5.16, and an epoxy value of 0.316 mol/100 g. CP-EGDE can be applied in the pickling-free and salt-free tanning processes to prepare wet white leather and the tannery wastewater with good degradability. The shrinkage temperature (Ts = 84.9 °C), grain flatness, fullness, softness, yellowing resistance, mechanical properties, absorptivity of traditional anionic fatliquor (88.4 %) and dyes (95.3 %) of CP-EGDE tanned leather exceeded those of commercial organic chrome-free tanning agents. This research considered both environmental protection and leather quality, especially greatly improving the absorptivity of traditional anionic wet finishing materials. CP-EGDE is expected to replace chrome tanning agents and has good application prospects.

Implantable and in-vivo shape-recoverable nanocellulose-hyaluronic acid composite hydrogel

Hydrogels have been used as a filling material in medical cosmetology, but current injection hydrogels have poor shaping ability due to its fluidity, while the hydrogels with fixed shape are easy to cause large wound size, resulting in rarely used in clinical practice. An implantable and in-vivo shape-recoverable hyaluronic acid (HA) based hydrogel is developed for tissue filling. In this work, complexes were made by hydrogen bonding between two natural polysaccharides: HA and TEMPO-oxidation cellulose nano-fiber. The elastic modulus of the HA/TOCN physical crosslinking hydrogel was maintained at 2500 G′ in Pa, while, when ethylene glycol diglycidyl ether was introduced in the hydrogel, the elastic modulus could reach 60,000 G′ in Pa. The volume of shrunk hydrogel reduced 80 ± 6 % of initial state, importantly, it can recover the shape in vivo inducing by extracellular moisture environment. Facts have proved that these shape recovery hydrogels were non-toxic to mammalian cells.

Yttria-stabilized tetragonal zirconia prepared using gel casting and two-stage sintering

ABSTRACT Gel casting technology and a two-stage sintering process were used to produce yttria-stabilized tetragonal zirconia (YTZP) ceramics with excellent mechanical properties. A carbonic acid-based polyelectrolyte dispersant was used as a dispersant to prepare a well-dispersed nano-sized (94 nm) zirconia slurry with a high solid content (45 vol%) for gel casting. The functional carboxyl groups of the polyelectrolyte dispersant reacted with epoxy monomer (ethylene glycol diglycidyl ether, EGDGE) as it was added to the slurry, resulting in a decrease in gelling incubation time and an increase in viscosity, resulting in gel casting failure. Adding hydroquinone (HQ) to the slurry can cause polymerization to be delayed and the gel-casting working time to be extended. To control grain growth, a two-stage sintering process was used. The temperature for the first stage of sintering was set at 1300°C, then lowered to 1240°C and soaked for 24 h in the second stage to achieve a relative density of greater than 99%. The two-stage sintered sample has a Vickers hardness of 15.2 GPa, fracture toughness of 7.8 MPa.m1/2, and flexural strength of 771 MPa.

Efficient recovery of europium by biosorption and desorption using beads developed from sericin residues from silk yarns processing, sodium alginate and poly(ethylene glycol) diglycidyl ether

The removal and recovery of critical rare-earth elements (REEs) are important from an environmental and economic perspective. The recovery of critical metals from secondary sources has received considerable attention. This work aims to evaluate the beads produced from sericin, alginate, and poly(ethylene glycol) diglycidyl ether (SA@PEGDGE) to recover Eu3+. The pH effect showed that pH 5.0 had the highest uptake of Eu3+ (0.289 ± 0.006 mmol/g) with stoichiometric cationic exchange with Ca2+ (0.425 ± 0.023 mmol/g) by SA@PEGDGE. The kinetic (pseudo-first order, pseudo-second order, and external diffusion) and equilibrium (Langmuir) models adequately represented the adsorption results. The particles had an increase in adsorptive capacity from 0.555 mmol/g at 25 °C to 0.633 mmol/g at 55 °C. Hydrochloric acid (0.1 mol/L) showed the highest recovery rate of Eu3+ (96.50 ± 0.84%) from SA@PEGDGE. Eu3+ recovery was highly successful for five cycles. The recovery was greater than 95% and the reuse of the eluent in the adsorption cycles enriched the Eu3+ concentration 10-fold, from 1.07 mmol/L to 9.96 mmol/L. The SA@PEGDGE also showed better performance for biosorption of Eu3+ with other competing ions. The characterization analyzes showed that the SA@PEGDGE beads produced by the ionotropic gelation technique have a spherical shape, surface with low roughness, and amorphous character. The mechanisms of Eu3+ biosorption involved interactions with the functional groups present on the SA@PEGDGE surface, cation exchange, and electrostatic interactions. Thus, the crosslinked sericin/alginate particles can be a sustainable alternative for the recovery of critical REEs from wastewater, resulting in social and economic benefits from a circular economy.

Novel and Integrated Process for the Valorization of Kraft Lignin to Produce Lignin-Containing Vitrimers.

The valorization of lignin into value-added products by oxidative conversion is a widely studied strategy. However, in many cases, this approach has limited scope for integration into industrial processes. The objective of our work is to maximize overall lignin utilization to produce diverse value-added products with a focus on integration in the existing industrial pulp and paper processes. The utilization of the sequential oxidation strategy using oxygen and ozone resulted in kraft lignin with a marked improvement in carboxyl content and also allowed the formation of vanillin and vanillic acid in the oxygen stage. The sequentially oxidized lignin (OxL-COOH) was then cured with poly(ethylene glycol) diglycidyl ether (PEG-epoxy) to form high-lignin-content (>48 wt %) vitrimers with high thermal stability, fast relaxation, swelling, and self-healing due to the presence of bond-exchangeable cross-linked networks. Overall, this study provides a novel approach for the multidimensional valorization of lignin and demonstrates an integrated approach for kraft lignin valorization in the pulp and paper industry.

Synthesis of Spherical Composite CMC-LTO-EGDE-ME for Lithium Recovery from Geothermal Water

In this study, ethylene glycol diglycidyl ether (EGDE) and melamine (ME) were used to prepare a spherical composite material CMC-LTO-EGDE-ME through the strategy of cross-linking reaction of biodegradable sodium carboxymethyl cellulose (CMC) with Li2TiO3 (LTO) to improve the cycle stability of the adsorption-desorption for lithium recovery. In the geothermal water at 333.15°K, the adsorption capacity of the spherical composite adsorbent for lithium-ion is 12.02 mg/g, and the adsorption equilibrium time is 8 h. There is a good selectivity of Li+ (Kd = 3.7 × 103) and high separation factors between Li+ and Na+, K+, Cs+ and Ca2+ (between 39.17 and 181.97). Studies on adsorption kinetics and adsorption isotherm showed that composite material’s adsorption process was obtained from the pseudosecond-order kinetics and the molecular diffusion model. It was found that the composite material has broad applications in lithium recovery from geothermal water.

Hydrotropic Hydrogels Prepared from Polyglycerol Dendrimers: Enhanced Solubilization and Release of Paclitaxel.

Polyglycerol dendrimers (PGD) exhibit unique properties such as drug delivery, drug solubilization, bioimaging, and diagnostics. In this study, PGD hydrogels were prepared and evaluated as devices for controlled drug release with good solubilization properties. The PGD hydrogels were prepared by crosslinking using ethylene glycol diglycidylether (EGDGE). The concentrations of EGDGE and PGDs were varied. The hydrogels were swellable in ethanol for loading paclitaxel (PTX). The amount of PTX in the hydrogels increased with the swelling ratio, which is proportional to EGDGE/OH ratio, meaning that heterogeneous crosslinking of PGD made high dense region of PGD molecules in the matrix. The hydrogels remained transparent after loading PTX and standing in water for one day, indicating that PTX was dispersed in the hydrogels without any crystallization in water. The results of FTIR imaging of the PTX-loaded PGD hydrogels revealed good dispersion of PTX in the hydrogel matrix. Sixty percent of the loaded PTX was released in a sink condition within 90 min, suggesting that the solubilized PTX would be useful for controlled release without any precipitation. Polyglycerol dendrimer hydrogels are expected to be applicable for rapid release of poorly water-soluble drugs, e.g., for oral administration.

Degradation of 2,4-DCP by the immobilized laccase on the carrier of sodium alginate-sodium carboxymethyl cellulose.

In this paper, sodium alginate-sodium carboxymethyl cellulose (SA-CMC) composite material was used as a carrier, and sodium alginate-embedded laccase (Lac@SC) was prepared by traditional embedding method. After that, ethylene glycol diglycidyl ether (EGDE) and glutaraldehyde (GLU) were used as cross-linking agents, two different cross-linking-embedded co-immobilized laccases (Lac@SCG and Lac@SCE) were innovatively prepared, respectively, and then these immobilized laccases were characterized by SEM, FT-IR and XRD, and the stability of the three immobilized laccases was explored. In addition, the effects of different factors on the removal of 2,4-DCP by immobilized laccase were studied, and the degradation kinetic models of three immobilized laccases on 2,4-DCP were summarized, the possible degradation pathways of pollutants were also given. Experimental results showed that compared to free laccase, the pH stability, thermal stability and storage stability of immobilized laccase were greatly improved. These immobilized laccases could maintain high activity at pH3~6, 45~55°C. Lac@SCG had the best storage stability. After 30days of storage, the relative enzyme activity was still more than 40%. Lac@SC had good reusability, the relative enzyme activity was still more than 50% after 5 uses. In the degradation of 2,4-DCP, all three immobilized laccases showed good performance, when Lac@SCE was at pH5, 35°C, 25h, the removal rate of 2,4-DCP could reach 95.2%; When at 45°C, Lac@SC had the highest degradation rate which reach to 94%; At 45°C, the degradation rate of Lac@SCG reached 83.2%.

Sustainable lignin precursors for tailored porous carbon-based supercapacitor electrodes

Sustainable materials are attracting a lot of attention since they will be critical in the creation of the next generation of products and devices. In this study, hydrogels were effectively synthesized utilizing lignin, a non-valorised biopolymer from the paper industry. This study proposes a method based on utilizing lignin to create highly swollen hydrogels using poly(ethylene) glycol diglycidyl ether (PEGDGE) as a crosslinking agent. The influence of different crosslinker ratios on the structural and chemical properties of the resultant hydrogels was investigated. Pore size was observed to be lowered when the amount of crosslinker was increased. The inclusion of additional hydrophilic groups in the hydrogel network decreased the swelling capacity of the hydrogels as the crosslinking density increases. These precursor materials were carbonised and electrochemically tested for application as electrodes for supercapacitors with capacitance characterized as a function of crosslinker ratio.

Construction of modified MXene with “organic–inorganic” structure to enhance the interfacial and mechanical properties of UHMWPE fiber-reinforced epoxy composite

A type of MXene nanosheets with “organic–inorganic” structure was constructed through chemical reactions of 3-aminopropyltriethoxysilane and ethylene glycol diglycidyl ether on MXene surface to improve the interfacial and mechanical properties of ultrahigh-molecular weight polyethylene (UHMWPE) fiber-reinforced epoxy composite. The soft “organic” portion was conducive to good dispersion of epoxy-modified MXene nanosheets (M−MXene) in epoxy resin, whereas the “inorganic” part guaranteed the excellent mechanical performance of M−MXene. Then, M−MXene nanosheets were added into the epoxy matrix or deposited onto the surface of modified UHMWPE fibers to investigate the effect of M−MXene on composites’ properties. Results indicated the introduction of M−MXene could increase friction force and mechanical interlocking, produce excellent wettability with epoxy matrix, and form chemical bonds with the curing agent. Then, reduced stress concentration and complicated crack path were formed due to the unique “organic–inorganic” structure. Compared with UHMWPE/Epoxy, UHMWPE-PAS@M−MXene/Epoxy and UHMWPE-PAS/Epoxy@M−MXene illustrated significant improvements of 39% and 56%, respectively, in tensile strength and 311% and 324%, respectively, in interfacial shear strength (IFSS). Improved mechanical and interfacial properties of UHMWPE-PAS/Epoxy@M−MXene were attributed to the uniform distribution of M−MXene in the epoxy matrix, which generated a longer crack path from fiber to matrix and more crack deflections compared with those of UHMWPE-PAS@M−MXene/Epoxy.

Preparation of a laminated structured polyethyleneimine cryogel for carbon capture.

A cryogel solid amine adsorbent with a laminated structure has been prepared by crosslinking polyethylenimine (PEI) with ethylene glycol diglycidyl ether (EGDE) at a low temperature via liquid nitrogen treatment and freeze-drying. The effects of cryogenic treatment on the morphology of the cryogels were investigated. The liquid nitrogen treatment and freeze drying were critical to create the layered structure. The fast formation of ice crystals at 77K served as a template which directed the ordered lamellar structure of the PEI and EGDE cross-linked polymer networks. The PEI cryogel adsorbent showed excellent CO2 adsorption performance both in dry and wet conditions. In dry conditions, the PEI-gel-5-0.25 cryogel showed a 5.60mmol/g of CO2 adsorption capacity at 75°C. After being swelled with water, the PEI-gel-15-0.25 cryogel showed an extremely high CO2 adsorption capacity of 11.39mmol/g at 25°C. The adsorption behaviors of adsorbents with varied water contents were explained using kinetic simulations and intraparticle diffusion simulations. It was found that the presence of water can significantly enhance the diffusion process. The regeneration performance was examined in both dry and wet conditions. After 20 adsorption-desorption cycles, the adsorption capacity of the regenerated PEI cryogel had barely decreased, indicating reliable regeneration stability.

One-step crosslinking preparation of tannic acid particles for the adsorption and separation of cationic dyes

In this study, a new tannic acid adsorbent (ethylene glycol diglycidyl ether crosslinked tannic acid, TA-EGDE) for adsorptive removal of dyes from water was prepared using EGDE as a cross-linking agent. The resultant TA-EGDE was in particulate form with rough surface morphology and a diameter ranging from 10 to 30 µm. The adsorption performance of the TA-EGDE was evaluated in a flow-through mode using water samples contaminated with methylene blue (MB) and two-component mixed dyes, respectively. The TA-EGDE provided adsorption capacity up to 721.8 mg·g−1 at 65 °C for MB. It showed a high removal efficiency (99%) of MB (50 mg·L–1) from the water sample and could recovery 90% of the adsorbed MB by eluting with acidic ethanol aqueous solution. The excellent adsorption of MB and neutral red on the TA-EGDE may be the result of the synergy of electrostatic interaction and π–π interaction. Furthermore, the TA-EGDE could separate dyes from water samples contaminated with two-component mixed dyes with a separation coefficient ranging from 1.8 to 36.5. The anionic TA-EGDE would be an effective adsorbent to remove and recycle dyes from the contaminated water.

Electrochemical and Optical Evaluation of the Stability of Enzymatic Hydrogels (BPEI-GOx) Used in Glucose Biosensors

At present, research and development of a large number of new devices for the detection and quantification of biomedical analytes incorporated into miniaturized platforms of high interest such as organ-on-a-chip (OCC), lab-on-a-chip (LOC), and implantable devices. Together, these systems are characterized by taking continuous measurements for long periods (hours, days, weeks) of the products and/or by-products generated by these platforms[1, 2]. Based on the above, it is essential to detect the failure mechanisms of the systems developed to make improvements in the operational stability of these devices, which could generate biosensing instruments with a longer life span.In this work, the stability of hydrogels was evaluated for the detection of glucose, made up of the branched polyethyleneimine/glucose oxidase (BPEI/GOx) system using ethylene glycol diglycidyl ether (EGDGE) and glutaraldehyde (GA) as crosslinking agents. The stability of these systems was evaluated by light, fluorescence, and electrochemical microscopy (SECM).First, the hydrogels formed were deposited by drop-casting on glass surfaces, gold, and a combination of both (polycrystalline gold chips deposited on glass substrates). The surfaces were treated with different cleaning methodologies and the impact they had on the adhesion of the hydrogels was subsequently evaluated. For their part, the hydrogels were subjected to different conditions such as exposure to aqueous media and potential disturbances to measure their adhesion to the surfaces described. The results showed that, when cleaning the surfaces with the RCA process for 15 minutes, both the hydrogels with EGDGE and GA show better adhesion. Likewise, both hydrogels showed better adherence on gold surfaces compared to glass ones. This can be attributed to electrostatic interactions between the surface and the amino groups present in BPEI and GOx.Subsequently, the spatial arrangement of the BPEI and GOx of both systems was evaluated by fluorescence microscopy and SECM. For this, the GOx was labeled with the fluorophore fluorescein-5-isothiocyanate (FITC) and the BPEI with tetramethylrhodamine-5-Isothiocyanate (5-TRITC). The hydrogels were irradiated with blue, green, and UV light. In the fluorescence images of the controls, unlabeled hydrogels, it was observed that when cross-linked with GA, there was an intense emission of fluorescence at the three wavelengths evaluated. According to the literature, this fluorescence can be attributed to the mechanism proposed by Liu et al.[3] which is based on the formation of Schiff bases from the reaction between aldehydes and amino acid residues. The above-described mechanism was used to confirm the crosslinking reaction between BPEI and enzyme with the crosslinking agent. On the other hand, in hydrogels with EGDGE, heterogeneous structures are seen, in which the distribution of each of the labeled components can be observed. Which facilitated the measurement of stability to time. The spatial arrangement of the enzyme and its stability to time was also evaluated by SECM using the generation of the substrate/collection at the tip (SG/TC) method. A 15 µm Pt UME was used, applying a potential of 0.45 V vs Ag│AgCl to follow the oxidation of H2O2 generated by the enzymatic reaction.As a final step, the concentration of EGDGE and GA was varied to observe the behavior of the hydrogels for the electrochemical detection of different concentrations of glucose in 0.1 M phosphate buffer pH 7.4, following the oxidation of H2O2. Calibration curves were made by chronoamperometry of solutions with concentrations of 0-50 mM of glucose. For EGDGE, the concentration of the solutions ranged from 7.5 to 20%. The results obtained showed that the variation in the concentration of the crosslinker does not affect the diffusion of glucose or H2O2 through the hydrogel and therefore the currents obtained are very similar. In the case of GA, the concentration of the solutions ranged from 4.5 to 0.45%. In this system, it was observed that the concentration of crosslinker significantly affects the diffusion of glucose and/or H2O2 through the hydrogel, reflecting on the currents obtained. In this way, it was determined that the GA concentration of 0.45% allows efficient diffusion through the hydrogel, allowing an increase in the current as of the glucose concentration increases.References Lopez GA, Estevez M-C, Soler M, Lechuga LM (2017) Recent advances in nanoplasmonic biosensors: applications and lab-on-a-chip integration. Nanophotonics 6:123–136. https://doi.org/doi:10.1515/nanoph-2016-0101Rebelo R, Barbosa AI, Correlo VM, Reis RL (2021) An Outlook on Implantable Biosensors for Personalized Medicine. Engineering. https://doi.org/https://doi.org/10.1016/j.eng.2021.08.010Liu SG, Li N, Ling Y, et al (2016) pH-Mediated Fluorescent Polymer Particles and Gel from Hyperbranched Polyethylenimine and the Mechanism of Intrinsic Fluorescence. Langmuir 32:1881–1889. https://doi.org/10.1021/acs.langmuir.6b00201

Self-Crosslinking Poly(Ethylene Glycol) Diglycidyl Ether in Water-in-Salt Electrolytes for Minimal Hydrogen Evolution Reactions and Extended LiTFSI Solubility

Water-in-salt electrolytes - WISEs - are prevailing thanks to their compelling extended voltage window due to the reduced free water molecules at the electrode interface. However, as has been reported elsewhere, free-water content still can be reduced further. In our previous work, an unstable phenomenon of solid electrolyte interphase (SEI) and salt precipitation/dissolution issue were revealed. Herein, we propose a novel approach in order to alleviate those issues using poly(ethylene glycol) diglycidyl ether (PDE) as an additive. Indeed, upon mixing LiTFSI, water and PDE at high concentrations, we observed a ring-opening reaction of PDE that was confirmed via Raman spectroscopy, FTIR and ionic conductivity measurements. These crosslinked networks could also increase the solubility limits of LiTFSI in water, which was identified by adding more LiTFSI or LiOTf. Differential scanning calorimetry (DSC) measurement demonstrated that these crosslinked electrolytes effectively suppress the crystallization of water molecules with the WISE. Linear sweep voltammetry (LSV) measurements revealed that these novel crosslinked electrolytes considerably reduce free water content which effectively drives the HER to more negative potentials. More significantly, the SEI formed with these novel electrolytes remains present and stable on the electrode surface after a resting period of 1 h. Our work herein offers a new approach to tackling SEI instability and precipitation/dissolution issues.

Designed loose nanofiltration membrane for efficient separation of low molecular dye/salt

AbstractEfficient selective separation of low molecular weight dye/salt system is of great significance for promoting the development of membrane technology in the field of wastewater treatment. In this study, a loose nanofiltration membrane (LNF) was fabricated for the desalination of dye wastewater through a facile method. Firstly, styrene‐co‐maleic anhydride (SMA) containing anhydride group was added to PES membrane by blending, then polyethylene imide (PEI) was grafted onto the membrane surface by the reaction between amino group and anhydride group. Finally, the unreacted NH2 on the membrane surface were used for secondary cross‐linking with glutaraldehyde (GA) and ethylene glycol diglycidyl ether (EGDE) to obtain GA‐NF and EGDE‐NF membranes. Results showed that nanofiltration membranes with narrow pore size distribution and uniform structure are obtained. Compared with the aldehyde group in GA, the epoxy group in EGDE monomer has higher reactivity and hydrophilicity, which reacts with the amine group of PEI molecule to form hydrophilic hydroxyl group. Therefore, the water flux of EGDE‐NF membrane was about 20% higher than that of GA‐NF membrane, and the rejection of CR, AF, and EBT dyes was increased to more than 99%. Through chemical treatment of acid and alkali, both GA‐NF and EGDE‐NF membranes showed excellent separation performance stability.

Preparation and Enzyme Degradability of Spherical and Water-Absorbent Gels from Sodium Carboxymethyl Cellulose.

To synthesize a biodegradable alternative to spherical polyacrylic acid absorbent resin, spherical hydrogel particles were prepared from carboxymethyl cellulose (CMC) dissolved in an aqueous solution, using ethylene glycol diglycidyl ether (EGDE) as a crosslinking agent. The effect of varying the initial CMC concentration and feed amount of EGDE on the shape, water absorbency, water-holding capacity, and enzyme degradability of the resultant CMC hydrogels was determined. The reaction solution was poured into fluid paraffin, and spherical hydrogel particles were obtained via the shear force from stirring. The shape and diameter of the spherical hydrogel particles in the swollen state depended on the CMC concentration. The spherical hydrogel particles obtained by increasing the amount of EGDE resulted in a decrease in absorbency. Additionally, all the spherical hydrogel particles were degraded by cellulase. Thus, spherical biodegradable hydrogel particles were prepared from CMC, and the particle size and water absorption of the hydrogel could be controlled in the range of 5–18 mm and 30–90 g·g−1 in the swollen state, respectively. As an alternative to conventional superabsorbent polymers, the spherical CMC hydrogels are likely to be useful in industrial and agricultural applications.

Preparation of a Fiber-Like 3D-Structured Adsorbent for CO2 Capture.

Solid amine adsorbents are promising materials to mitigate global warming. In this study, a commercially available melamine-formaldehyde sponge was adopted as a support to prepare a kind of solid amine adsorbent using polyethylenimine as a functional component and ethylene glycol diglycidyl ether as a cross-linker. The adsorbent, with abundant tunnels and a high amine loading amount, had a high adsorption capacity. When the amine loading was 89.6 wt%, the as-prepared adsorbent showed a high adsorption capacity of 7.29 mmol/g at 20 °C in the presence of water. The spent adsorbent could be easily regenerated by heating it at 90 °C, resulting in lower energy consumption. It has been proved by the Avrami model that physical and chemical adsorption coexist in the adsorption of CO2 on this adsorbent. Simulation with the intraparticle diffusion model has revealed that the rate-controlling step in the adsorption process was the gas film diffusion period when the adsorption temperature was below 30 °C, while it was the adsorption equilibrium period when the adsorption temperature was above 30 °C.

Modification of PP Fabric with Polyols by the Plasma Composite Technique

Abstract In order to endow polypropylene (PP) fabric with hydrophilic and antistatic properties, PP was grafted with polyols (sorbitol, maltitol and polyethylene glycol (PEG)) by the oxygen plasma treatment and subsequent bridging process, where ethylene glycol diglycidyl ether (EGDE) and trimethylolpropanetris (2-methyl-1-aziridinepropionate) (TTMA) were used as crosslinkers. The highest grafting rate was 7.48%. The chemical structure changes were analysed by Fourier transform infrared spectroscopy (FTIR). A scanning electron microscope (SEM) was used to observe the changes in polypropylene fiber surface morphology. The hydrophilicity was characterized by testing loose fiber suspension and moisture retention. The modified PP was more easily immersed in water and the desorption behaviour continued for 2h without equilibrium. The half-life of the grafted PP was reduced to 7s. The results showed that the modified PP with polyols possessed hydrophilicity and antistatic properties.

Preparation and characterization of soy protein-based adhesive modified by microcrystalline cellulose

With the desire of promoting the further development of wood production, Soy protein-based adhesives (SPs) have been modified to overcome the defect of poor water resistance in the existing reports. Herein, the microcrystalline cellulose (MCC) was grafted by 3-Glycidyloxypropyltrimethoxysilane (KH560) to obtain a modified microcrystalline cellulose (MMCC). The soybean flour was mixed with ethylene glycol diglycidyl ether/diethylenetriamine (EGDE/DETA) and the MMCC to prepare the modified soy protein-based adhesive. The results showed that the adhesive with multiple additives had a better performance due to the interpenetrating network structure of soy protein molecules. The contact angle (CA) increased from 33.97° to 58.88°. The wet bonding strength increased to 0.99 MPa. Consequently, the objective of this study is to provide a new strategy for manufacturing a new environmental adhesive.

Synthesis of chitosan–magnetite gel microparticles with improved stability and magnetic properties: A study on their adsorption, recoverability, and reusability in the removal of monovalent and multivalent azo dyes

Here, the membrane emulsification technique was employed to synthesise novel size-controlled chitosan–magnetite emulsion droplets (diameter: 10–35 μm), which were subsequently converted into hydrogels via alkaline gelation and crosslinking with ethylene glycol diglycidyl ether (EGDE). The microscopy images revealed the efficient trapping of the magnetite nanoparticles within the chitosan emulsion droplets and crosslinked gel matrices. The microparticles exhibited an ideal surface morphology, which yielded a dye-removal percentage of 97% (pH 4), as well as a quick magnetic response. The adsorption reaction employing the chitosan–magnetite gel microparticles correlated with the Langmuir adsorption isotherm, exhibiting remarkable adsorptions towards Acid Orange 7 (AO7, monovalent), Acid Red 13 (AR13, divalent), and Acid Red 27 (AR27, trivalent) dyes with maximum adsorption capacities, Qmax, of 1.71, 1.55, and 1.13 g-dye/g-dry adsorbent, respectively, in a pH 5 buffer. The calculated molar ratio of the adsorbed dyes revealed the contributions of almost all the amino groups of the chitosan gel microparticles to the adsorption of AO7 dye. The fast and efficient recovery of the adsorbent microparticles by magnets, as well as their reusability for over 10 adsorption–desorption cycles without any particle loss or significant decrease in adsorption capacities, were demonstrated. The synthesised chitosan–magnetite gel microparticles could be a “green” state-of-the-art adsorbent exhibiting excellent properties for applications in wastewater treatment.