Hydrophobic Modification Research Articles

Impact of hydrophobic modification on biocompatibility of Alaska pollock gelatin microparticles.

This study investigates the impact of hydrophobic modification on the immunogenicity, cytotoxicity, and inflammatory response of Alaska pollock gelatin (ApGltn) microparticles (MPs). Gelatin, known for its inherent biocompatibility, was modified with decyl group (C10) to explore potential alterations in its interaction with the immune system. Immunogenicity was evaluated through the measurement of material-specific IgM and IgG responses, indicating no significant increase post-modification. Cytotoxicity against Caco-2 cell lines and NF-κB-mediated LPS-induced inflammation were also assessed, revealing no exacerbation by the modified MPs. Furthermore, C10 modification with different types of linkage such as secondary amine and amide structure did not influence immune reactivity. These findings suggest that C10 modification maintains the non-immunogenicity and biocompatibility of gelatin MPs, supporting their potential use in biomedical applications.

Preparation and characterization of micro-cellular melamine foam supported SiO2 aerogel for building thermal insulation

This study aims to complement the advantages of SiO2 aerogel and melamine foam (MF) to produce high-performance building insulation materials. The optimal sol–gel scheme was determined by controlling system temperature, water content, amount of ethanol and amount of acid-base catalyst (orthogonal experiment). The density and porosity of MF/SiO2 aerogel were regulated by adjusting aging time, aging temperature and type of aging agent. Furthermore, the effects of different volume fractions hydrophobic modifier on the surface free energy and wettability of MF/SiO2 aerogel were also investigated. The experiment results showed that the prepared MF/SiO2 aerogel satisfies requirements for low density (0.089 g/cm3), low thermal conductivity at room temperature (0.0256 W m−1·K−1), and excellent hydrophobic performance (the contact angle was 140.1°). Meanwhile, it was found that SiO2 aerogel was stably and uniformly distributed in the pores of the MF and effectively enhanced the mechanical property (a maximum compressive strength of 0.2058 MPa), heat-shielding performance, flame retardant property, and sound absorption capacity(αmax = 0.76, αave = 0.31).Therefore, the MF/SiO2 aerogel composites exhibit exceptional application potential in comparison to conventional building insulation materials (such as EPS, Rock wool board, etc.) due to their significantly low thermal conductivity and remarkable flame retardant properties.

Super-hydrophobic ceramic membrane with dense and robust silane grafting for efficient water-in-oil emulsion separation

Separate water from water-in-oil (W/O) emulsions is essential in oil resources recycling and wastewater treatment. Hydrophobic ceramic membranes (HCM) have shown great potential in the dehydration of W/O emulsions but developing high-performance HCM is still a challenge due to the difficulty in hydrophobic modification of ceramic membranes. In this study, an HCM with high grafting density and robust structure was prepared by the grafting silane coupling agent onto an attapulgite (ATP) ceramic membrane. The hexadecyltrimethoxysilane (HDTMS) was chosen for membrane surface modification considering its reaction activity and stability based on molecular dynamic simulation. The effect of the HDTMS contents in the grafting solution and reaction time on the membrane properties were examined. The ATP membrane grafted by HDTMS solution with a content of 9600 ppm for 24 h had a water contact angle of 161° and oil permeability larger than 2207.5 L·m−2·h−1·bar−1 (LMHB). When dealing with W/O emulsions with a water content of 10000 ppm, the steady permeability, permeability recovery ratio, and water rejection of ATP-based HCM was 362 LMHB, 97 %, and 99 %, respectively. Ascribe to the –OH-rich nature of ATP, the performance of HCM in this work is superior to most membranes including Al2O3, ZrO2, and SiC. Hydrophobic-modified ATP provides a new idea for the development of high-performance HCM based on natural mineral ceramics.

Hydrophobic Thiophene Unit Modification for the Construction of Novel Anion Exchange Membranes for High-Speed Transport of Ion Channels

Hydrophobic Thiophene Unit Modification for the Construction of Novel Anion Exchange Membranes for High-Speed Transport of Ion Channels

Preparation and mechanism research on hydrophobic coupling modification of HTV silicone rubber

Neat high-temperature vulcanized silicone rubber (HTV SR) showed bad hydrophobicity due to the existence of a large number of inorganic reinforcing fillers on its surface, which affected its security application in outdoor insulation systems. In this work, hydrophobic silane chains were grafted onto the surface of inorganic particles on the skin layer of HTV SR by a one-step coupling modification to improve its hydrophobicity. The effects of coupling agent types and coupling reaction conditions on the hydrophobicity of HTV SR were investigated. It was determined that the perfluorooctane trichlorosilicon with a large number of low surface energy fluorine atoms was the preferred coupling agent. The contact angle of HTV SR was increased by 15.70% when the optimal coupling reaction conditions were determined to be a reaction temperature of 60°C, a reaction time of 4 h, and an amount of coupling agent of 0.5%. The study found that both etching reaction and grafting reaction occurred during the whole coupling modification process, which led to the disappearance or decrease of a lot of holes on the HTV SR surface. After the fluorination coupling reaction, the surface of HTV SR became smooth and dense that led to the decrease of water absorption. The result of Fourier-transform infrared spectroscopy analysis showed the formation of C-F bond in HTV SR after fluorination modification, and the energetic dispersive spectroscopy analysis showed that the fluorine content on the surface of the fluorinated HTV SR increased significantly. Moreover, the stability analysis showed that the fluorinated HTV SR still had a good thermal stability and mechanical property stability.

Hydrophobic Dendritic Modification of a Poly(acrylamide-co-acrylic Acid) Copolymer with Behera′s Amine as Viscous Agent

Hydrophobic Dendritic Modification of a <i>Poly</i>(acrylamide<i>-co-</i>acrylic Acid) Copolymer with Behera′s Amine as Viscous Agent

A novel strategy for iodine removal from nuclear reactor accidental gases: efficient adsorption of CH3I on the moderately hydrophobic modified silver-loaded zeolite under high temperature and humidity conditions

ABSTRACT Ensuring nuclear energy safety through effective gas emission filtration from nuclear reactor containment in accident scenarios is paramount. The efficacy of hydrophobic modified Ag-loaded zeolites for methyl iodide (CH3I) removal under challenging conditions of high temperature, humidity, and irradiation is studied in this work. Through hydrophobic modification of AgX zeolite with three different silane coupling agents, a series of modified zeolites with varied hydrophobicity levels is produced. The adsorption capabilities of these modified materials are assessed using a self-designed gas adsorption setup, focusing on CH3I removal from a gas mixture emblematic of nuclear accident environments. Results indicate that all hydrophobically modified zeolites exhibited superior CH3I removal rates compared to their unmodified counterparts, with the variant modified with 10% phenyltriethoxysilane achieving the highest removal rate of 99%. Additionally, zeolites modified with octyltrimethoxysilane demonstrate commendable irradiation resistance at a radiation dose of 4.2 × 105 Gy. The results suggest that optimally hydrophobically modified AgX zeolites hold significant promise for filtering gases containing radioactive iodine, offering novel insights for the advancement of adsorbent materials in nuclear reactor containment discharge systems.

Effect of hydrophobic modification and dosage of long afterglow phosphors on the properties of self-luminescent cement-based materials

Both the hydrolysis instability of original long afterglow phosphors (OLP) and limited amount of reflective powders (RP) degraded the luminescent performance of self-luminescent cement-based materials (SLCM). This study novelty proposed a solution by coating organosilicon layer on the OLP surface to create hydrophobic effect for enhancing its water resistance. Furthermore, compared with typical SLCM with low content of LP and RP, SLCM mixtures were prepared through replacing cement by LP and containing higher volume of RP according to the modified Andreasen and Andersen (A&A) model. The effects of dosage and surface modification of LP on the strength, hydration kinetics, luminescent performance, phase composition and microstructure of SLCM were examined. Hydrophobic LP (HLP) achieved similar crystal structure but changed its surface morphology as well as enhanced its water resistance. Introduction of the OLP into SLCM was liable to generate the hydrolysis products. HLP performed better in generating more hydration products but less hydrolysis products, thus formed a compact microstructure and enhanced the thermal stability. Hydration kinetics revealed that the hydrolysis reaction of OLP decreased the heat of hydration, while the hydration process was promoted by HLP. Higher dosage of LP after hydrophobic modification in SLCM helped in obtaining a better luminescent performance but caused a drastic reduction in strength. Overall, the optimal dosage of HLP in SLCM including higher volume of RP was more effective in achieving a superior luminescent performance without degrading the strength.

The hydrophobicity of the CARD8 N-terminus tunes inflammasome activation

Mounting evidence indicates that proteotoxic stress is a primary activator of the CARD8 inflammasome, but the complete array of signals that control this inflammasome have not yet been established. Notably, we recently discovered that several hydrophobic radical-trapping antioxidants (RTAs), including JSH-23, potentiate CARD8 inflammasome activation through an unknown mechanism. Here, we report that these RTAs directly alkylate several cysteine residues in the N-terminal disordered region of CARD8. These hydrophobic modifications destabilize the repressive CARD8 N-terminal fragment and accelerate its proteasome-mediated degradation, thereby releasing the inflammatory CARD8 C-terminal fragment from autoinhibition. Consistently, we also found that unrelated (non-RTA) hydrophobic electrophiles as well as genetic mutation of the CARD8 cysteine residues to isoleucines similarly potentiate inflammasome activation. Overall, our results not only provide further evidence that protein folding stress is a key CARD8 inflammasome-activating signal, but also indicate that the N-terminal cysteines can play key roles in tuning the response to this stress.

Corn Stalk-Derived Cellulose Aerogel/Poly(vinyl alcohol): Impact of Hydrophobic Modifications on the Adsorption Activity and Assessment of Thermal Insulation Perspective

Corn Stalk-Derived Cellulose Aerogel/Poly(vinyl alcohol): Impact of Hydrophobic Modifications on the Adsorption Activity and Assessment of Thermal Insulation Perspective

Preparation of lightweight porous slag-based geopolymer highly hydrophobic materials for efficient oil-water separation

Surface hydrophobic modification is a critical technology for enhancing the application properties of materials, crucial for the development of geopolymer materials in oil-water separation. in this study, a lightweight porous slag-based geopolymer highly hydrophobic materials (PSGHHMs) were successfully prepared in-situ using slag and liquid water glass by varying different influencing factors, such as the amount of water/foaming agent/polymethylhydrosiloxane (PMHS) and the curing temperature. The PSGHHMs exhibited high strength, large flux and excellent highly hydrophobic properties, with contact angle reaching 156.14° and a sliding angle of less than 2°. SEM-EDS, TG-DSC and FT-IR analysis reveal that the in-situ modification mechanism of PSGHHMs involves the hydrolysis of Si-H in PMHS under alkaline conditions to form Si-OH. This subsequently reacts with Ca-OH in C-S-H gel to produce Ca-O-Si. Consequently, the PSGHHMs retained their excellent highly hydrophobicity even after calcination at 450℃ for 2.5 h. The PSGHHMs demonstrated robust resistance to acid/alkali/salt corrosion, as well as to friction, with the ability to quickly restore damaged highly hydrophobic properties. Additionally, the PSGHHMs could quickly absorb light/heavy oils, and achieving a desorption efficiency of over 99 %. They were also capable of continuously separation of oil-in-water emulsions and oil-water mixtures. Given these properties, the PSGHHMs have broad potential applications in antifreezing, antifogging, drag reduction and oil-water separation.

Nanocellulose-assisted construction of multi-cavity structured Ti3C2Tx/melamine composite sponges for enhanced electromagnetic interference shielding

The deposition of Ti3C2Tx nanosheets onto an ultralight melamine sponge (MS) holds great appeal for constructing mechanically robust and high-performance electromagnetic interference (EMI) shielding composites. However, the full potential of Ti3C2Tx materials for shielding performance is impeded by the insufficient affinity between Ti3C2Tx nanosheets and MS. Herein, with the assistance of cellulose nanofibers (CNF), large-sized single-layer Ti3C2Tx nanosheets were firmly attached to the MS skeleton and enveloped the pores. The obtained Ti3C2Tx/MS composite sponges exhibit a unique multi-cavity structure. Moreover, hydrophobic modification was applied to the composites through the use of two-component silane coupling agents. The silane-modified multi-cavity structured composite sponges demonstrate significant enhancements in conductivity, mechanical strength, and environmental stability. Particularly, the incorporation of 17 wt% CNF leads to a 29.3 dB increases in shielding efficiency (SE) for the composite sponge. The enhancement can be attributed to the high reflectance of electromagnetic waves due to the highly conductive Ti3C2Tx/CNF cavity-membranes, the multiple internal reflections within the multi-cavity structure, and the improved interfacial polarization loss capability facilitated by the abundance of MXene-CNF interfaces.

Amphiphilic block and random copolymers: aggregation and hydrophobic modification on metal-free tanned collagen fibers

Hydrophobicity enhancement of metal-free leather, which is crucial for improving its comprehensive performance, can be achieved by using amphiphilic copolymer retanning agents. However, the relationship between the sequential structure and the hydrophobic modification effect of amphiphilic copolymers remains unclear. Herein, an amphiphilic block copolymer was synthesized using stearyl methacrylate and 2-(dimethylamino)ethyl methacrylate via atom transfer radical polymerization, and the corresponding random copolymer with similar monomer compositions and molecular weights was prepared for comparison. The aggregation behavior of block and random copolymers was investigated. DLS and TEM results indicate that the block copolymer exhibits a larger aggregate size than the corresponding random copolymer. Molecular dynamics simulations suggest that the block copolymer aggregate exhibit a thicker hydrophilic shell and more concentrated distribution of cationic DMA block than the random copolymer aggregate. Subsequently, the block and random copolymers were used for the hydrophobic modification of metal-free tanned collagen fibers (CFs). The block copolymer shows superior binding capacity to CFs than the random one because of its larger size and more concentrated charge distribution. Hence, the block copolymer can form a dense and uniform hydrophobic film on the surface of collagen fibrils and endow CFs with higher hydrophobicity than the random one. This work provides theoretical guidance for modulating the hydrophobicity of CFs by tailoring the sequential structure of amphiphilic copolymers, which is expected to inspire the manufacturing of high-performance metal-free leather.Graphical

Preparation and characterization of hydrophobically-modified sodium alginate derivatives as carriers for fucoxanthin

Micelles are nano-architectured structures capable of encapsulating hydrophobic substances in aqueous solutions, thereby improving their stability, solubility, and bioavailability to control the release of bioactive compounds. In this study, the sodium alginate backbone was modified via a hydrophobic modification scheme where octyl chains were covalently attached to the alginate chains via esterification reactions. Fourier-transformed infrared spectrometry (FTIR), 1H nuclear magnetic resonance (1H NMR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) were used to characterize the structure of the sodium alginate derivatives of varying molar mass (ALG-C8). Fluorescence spectroscopy, surface tension measurements, and dynamic light scattering (DLS) were employed to assess the self-assembly performance of ALG-C8. The three methods produced consistent results, indicating that self-assembly decreased with higher molar mass. The self-assembled ALG-C8 micelles were utilized to encapsulate fucoxanthin. The loading capacity (LC) and encapsulation efficiency (EE) were determined using UV–Vis spectrophotometry. The molar mass of ALG-C8 has a key influence on fucoxanthin loading and release behavior. The ALG-C8 molecules with the lowest molar mass produced micelles with the smallest hydration diameter, resulting in the highest LC and EE. Furthermore, the release of fucoxanthin is significantly influenced by the pH and ionic strength of the medium. ALG-C8 micellar-like aggregates exhibit resistance to low pH and high ionic strength environments, releasing encapsulated material at the target site under alkaline conditions. Therefore, synthesized ALG-C8 is a potential candidate for preparing pH-responsive self-assembled micellar-like aggregates, enabling targeted delivery and gradual release of hydrophobic functional food components.

Chitin-augmented wetting resistance and water-in-oil emulsion separation performance of silane-modified polyketone membrane

The utilization of membrane technology for separating water-in-oil (W/O) emulsions necessitates a membrane possessing high hydrophobic properties. However, the use of naturally hydrophobic membrane materials, such as polyvinylidene fluoride, is undesirable due to the persistence of fluorine-containing compounds in the environment. Polyketone (PK) membranes present a potential alternative, but their inherent hydrophilic properties can hinder the W/O emulsion separation process. To address this issue, hydrophobic modification of PK membranes can improve their performance in separating W/O emulsion. Natural hydrophobic materials like chitin offer a more sustainable alternative compared to synthetic materials. Chitin was introduced onto the membrane surface along with hexadecyltrimethoxysilane (HDTMS) subsequent to the initial reaction of the PK membrane with tetraethyl orthosilicate (TEOS). Comparative analysis revealed that the mixed chitin and HDTMS modification resulted in the lowest surface wettability compared to membrane modification using only TEOS, HDTMS, and chitin. Examination of membrane performance through toluene emulsion separation demonstrated increased permeability after modification, with permeate toluene purity over 99.8 %. Additionally, the chitin and silane-modified PK membrane exhibited a two-fold increase in filtration process permeability, indicating outstanding fouling resistance. These findings underscore the potential of natural compounds in imparting desired hydrophobic properties to membranes while minimizing reliance on synthetic materials.

Superhydrophobic ceramic membrane coupled with a biphasic solvent for efficient CO2 capture

An innovative strategy was proposed by integration of membrane contactor (MC) with biphasic solvent for efficient CO2 capture from flue gas. The accessible fly ash-based ceramic membrane (CM) underwent hydrophobic modification through silane grafting, followed by fluoroalkylsilane decoration, to prepare the superhydrophobic membrane (CSCM). The CSCM significantly improved resistance to wetting by the biphasic solvent, consisting of amine (DETA) and sulfolane (TMS). Morphological characterizations and chemical analysis revealed the notable enhancements in pore structure and hydrophobic chemical groups for the modified membrane. Predictions of wetting/bubbling behavior based on static wetting theory referred the liquid entry pressure (LEP) of CSCM increased by 20 kPa compared to pristine CM. Compared with traditional amine solvents, the biphasic solvent presented the expected phase separation. Performance experiments demonstrated that the CO2 capture efficiency of the biphasic solvent increased by 7%, and the electrical energy required for desorption decreased by 32%. The 60-h continuous testing and supplemental characterization of used membrane confirmed the excellent adaptability and durability of the CSCMs. This study provides a potential approach for accessing hydrophobic ceramic membranes and biphasic solvents for industrial CO2 capture.

Facile fabrication of superhydrophobic ZnO powders coated on polyurethane sponge for effective oil/water separation application

Oil spills pose significant challenges to the environment, wildlife, and local economies, thus an effective method for cleaning up an oil spill is urgent. Here, superhydrophobic ZnO powder particles were synthesized using a simple and efficient method and investigated their coating on polyurethane sponge for oil/water separation application. Initially, ZnO particles were prepared through a hydrothermal reaction of Zn(CH3COO)2 and NaOH solution in an autoclave. Subsequently, superhydrophobic ZnO particles were obtained through hydrophobic modification using either stearic acid or 1H, 1H, 2H, 2H-Perfluorooctyltriethoxysilane. The results demonstrate that the ZnO particles exhibited excellent superhydrophobic properties, with contact angle of 153o. After coating superhydrophobic ZnO particles on the polyurethane sponge, the surface became superhydrophobic/oleophilic and could adsorb oil with a capacity measured up to more than 40 times its own weight. Results demonstrate the promising application of superhydrophobic/oleophilic polyurethane sponge for oil/water separation.

An investigation of a strengthening polysaccharide interfacial membrane strategy utilizing an anionic polysaccharide-alkaline ligand interfacial assembly for all-liquid printing

The applications of polysaccharides as emulsifiers are limited due to the lack of hydrophobicity. However, traditional hydrophobic modification methods used for polysaccharides are complicated and involve significant mechanical and thermal losses. In this study, soy hull polysaccharide (SHP) and terminally aminopropylated polydimethylsiloxane (NPN) were selected to investigate the feasibility of a simple and green interfacial membrane strengthening strategy based on the interfacial polymerization of anionic polysaccharides and fat-soluble alkaline ligands. Our results show that deprotonated SHP and protonated NPN can be complexed at the water/oil (W/O) interface, reduce interfacial tension, and form a strong membrane structure. Moreover, they can quickly form a membrane at the W/O interface upon the moment of contact to produce stable all-liquid printing products with complex patterns. However, the molecular weight of NPN affects the complexation reaction. Consequently, this study has long-term implications to expanding the areas of application for anionic polysaccharides.

Microorganisms immobilized hydroxyethyl cellulose/luffa composite sponge for selective adsorption and biodegradation of oils in wastewater

The highly efficient removal of oils such as oils or dyes from wastewater has aroused wide concern and is of great significance for clean production and environmental remediation. The synthesis of a novel aerogel (designated as HEC/LS) is reported herein, achieved through a sol-gel method followed by freeze-drying utilizing loofa and hydroxyethyl cellulose as the raw materials. The new HEC/LS aerogel exhibits excellent porosity and specific surface area, with a porosity of 88.70 %, a total pore area of 0.607 m2 g−1, and a specific surface area of 230 m2 g−1. The prepared HEC/LS aerogel exhibits exceptional hydrophilicity and self-floatability, facilitating its rapid absorption of water up to 21 times its own weight within a mere 3 s. Additionally, it demonstrates good adsorption performance for methylene blue (MB), with a maximum adsorption capacity of 83.30 mg g−1. Subsequently, a new hydrophobic microorganisms-loaded composite aerogel (namely, Bn-HEC/LS) was obtained by doping microorganisms into the as-prepared HEC/LS in multiple enrichment followed by a hydrophobic and oleophilic surface modification. Based on its rich porous structure and oleophilic wettability, the as-synthesized Bn-HEC/LS exhibits excellent selective adsorption and degradation properties for the oil contamination, the diesel oil could be selectively absorbed in the Bn-HEC/LS and degraded by the loaded microorganisms. Among them, B5-HEC/LS displays the highest removal efficiency of 94.50 % within 180 h, while free microorganisms and HEC/LS aerogels show degradation efficiencies of only 21.70 % and 48.10 %, respectively. The fixation of microorganisms in the aerogel increases their number within the material and enhances the relative microorganisms removal capacity. The hydrophobic and lipophilic modifications improve the selective adsorption performance of the aerogel on diesel oil, resulting in a significantly high removal rate of Bn-HEC/LS for diesel oil. The results indicate that the immobilization of microorganisms into aerogel improves the activity of microorganisms, and the hydrophobic and oleophilic modification enhances the selective adsorption performance of aerogel to diesel oil, thus resulting in a very high removal rate of Bn-HEC/LS for diesel oil. This study is expected to provide a now possibility for the green and efficient bioremediation of oils.

Efficient synthesis of durable superhydrophobic SiO2@PFDMS coatings on bamboo by liquid deposition

Fast-growing bamboo offers a sustainable alternative to meet the increasing demand for wood. However, its inherent hydrophilicity limits its performance, necessitating hydrophobic modifications to enhance longevity. In this study, 1 H,1 H,2 H,2 H- perfluorodecyltrimethoxysilane was used to anchor SiO2 nanoparticles onto bamboo surface, creating superhydrophobic coatings. The nanoparticles constructed a micro-/nano-rough structure on the bamboo surface, and fluorosilanes significantly reduced the surface energy of bamboo. The wettability, micro-morphology, chemical composition, and resistance to acid and alkali corrosion, mechanical abrasion, and UV aging of the superhydrophobic coatings were extensively investigated. The results demonstrated that the modified bamboo achieved a surface energy of 0.2±0.0 J/m2 and a water contact angle of 156.8±0.2°. Furthermore, the coating exhibited excellent chemical and physical stability. This straightforward and effective surface treatment method offers substantial potential for broadening bamboo's applications in outdoor environments.