Optimal Modification Conditions Research Articles

Eco-friendly, stable, and high-performance biochar prepared by a twice-modification scheme: Saccharification of raw materials & thermal air oxidation of biochar

Organic pollutants, such as phenolic compounds, pose significant risks to both the environment and human health. While biochar is an effective adsorbent for removing these pollutants, its dissolved solid (DS) components can lead to the loss of functional groups, structural disintegration, unstable performance, and environmental issues. This study introduces a twice-modification scheme designed to produce a biochar (BC-M) that combines high stability with superior performance. The process begins with the preparation of a stable biochar from cellulase-treated lignocellulose. This precursor biochar is then subjected to thermal air oxidation to enhance its oxygen-containing functional groups, thereby improving its adsorption capabilities. A mathematical model was developed to explore the relationship between different thermal air oxidation conditions and the properties of BC-M, aiming to optimize both adsorption capacity and DS. The model's multi-objective optimization indicated the optimal modification conditions. Compared to unmodified biochar (BC-O), BC-M showed significant improvements: its specific surface area increased by 63.6%, pore volume by 139%, and functional groups by 50%–1271%. Notably, the DS of BC-M was reduced to just 1.08 mg/L, representing a 97.5% reduction from BC-O, with a minimal mass loss of only 0.78 ± 0.45% during modification. BC-M also demonstrated a remarkable enhancement in the adsorption of phenolic compounds, with a capacity 21%–2408% higher than BC-O. Furthermore, calculations indicated that BC-M could reduce carbon emissions by 0.70 t CO2/yr/t, outperforming activated carbon in this regard. This study offers valuable insights into biochar modification, providing a low-cost, high-stability, and high-efficiency alternative for environmental cleanup.

Additive manufacturing and in vitro study of biological characteristics of sulfonated polyetheretherketone-bioactive glass porous bone scaffolds

Polyetheretherketone (PEEK), a high-performance special engineering plastic, has gradually been used in bone substitutes due to its wear resistance, acid and alkali resistance, non-toxicity, radiolucency, and modulus close to that of human bone. However, its stable biphenyl structure determines strong biological inertness, thus artificial interventions are required to improve the biological activity of fabricated PEEK parts for better clinical applications. This study developed a novel strategy for grafting bioactive glass (BAG) onto the surface of PEEK through sulfonation reaction with concentrated sulfuric acid (H2SO4), aiming to improve the bioactivity of printed porous bone scaffolds manufactured by fused deposition modeling (FDM) to meet clinical individual needs. In vitro biological study was conducted on sulfonated polyetheretherketone-bioactive glass (SPEEK-BAG) scaffolds obtained by this strategy. The results demonstrated that the optimal modification condition was a 4-hour sulfonation reaction with 1 mol/L concentrated H2SO4 at high temperature and high pressure. The scaffold obtained under this condition showed minimal cytotoxicity, and the Ca/P molar ratio, yield compressive strength, and compressive modulus of this scaffold were 2.94 ± 0.02, 62.78 MPa, and 0.186 GPa respectively. The hydrophilicity and the biomineralization ability of PEEK modified by the proposed strategy were substantially improved. The SPEEK-BAG bone scaffolds exhibited excellent biocompatible properties, suggesting that the sulfonation reaction and BAG effectively enhanced the proliferation and differentiation of osteoblasts. The presented method provides an innovative, highly effective, and customized strategy to improve the biocompatibility and bone repair ability of printed PEEK bone scaffolds for virous biomedical applications.

Surface treatment optimization of mixed cellulose ester membrane by cold plasma treatment to improve apple juice clarification

This study aimed to determine the optimal conditions for the surface modification of mixed cellulose ester (MCE) microfiltration membrane by cold plasma (CP) for apple juice clarification. Response surface method using central cubic design (CCD) was employed for the optimization of the membrane surface modification process. Plasma gas type (oxygen, carbon dioxide, and air), power (10, 15, and 20 W), and exposure time (120, 180, and 240 s) were used as the factors for cold plasma surface modification. The results revealed the surface modification of the MCE membrane using air as plasma gas with plasma power and exposure time equal to 10 W and 180 s resulted in the maximum permeate flux in apple juice clarification. The results of scanning electron microscope, and atomic force microscope confirm the effect of CP treatment on the membrane surface roughness. Fourier transform infrared spectroscopy showed the incorporation of the hydroxyl group into the membrane surface due to CP treatment which affected the surface contact angle and hydrophilicity. The CP treatment of the membrane significantly affects the membrane resistances. Also, the surface modification of the MCE membrane using the CP treatment process in optimal conditions is an effective method for clarifying apple juice.

Modulating Carbon Fiber Surfaces with Vinyltriethoxysilane Grafting to Enhance Interface Properties of Carbon Fiber/Norbornene-Polyimide Composites.

In this study, vinyltriethoxysilane (TEVS) was introduced onto the surface of carbon fiber using liquid-phase oxidation and impregnation methods to incorporate vinyl groups onto the carbon fiber, thereby enhancing the chemical bonding between the carbon fiber and norbornene-polyimide (PI-NA). Through a systematic study of the hydrolysis conditions and concentration of the TEVS solution, the optimal modification conditions were determined. These conditions were used to graft TEVS onto the surface of oxidized carbon fiber to prepare carbon-fiber-reinforced PI-NA composites (CF/PI-NA). The results show that when carbon fiber was treated with a 0.4 wt% TEVS solution, the interlaminar shear strength (ILSS) of the composites reached 65.12 MPa, and the interfacial shear strength (IFSS) reached 88.58 MPa, representing increases of 27.58% and 35.62%, respectively, compared to the CF/PI-NA composite materials prepared from untreated carbon fiber. It is worth noting that the modification method described in the study is simple and easy to implement, and it has the potential for large-scale continuous production applications.

A Novel, Dual-Initiator, Continuous-Suspension Grafting Strategy for the Preparation of PP-g-AA-MAH Fibers to Remove of Indigo from Wastewater.

The indigo dye found in wastewater from printing and dyeing processes is potentially carcinogenic, teratogenic, and mutagenic, making it a serious threat to the health of animals, plants, and humans. Motivated by the growing need to remove indigo from wastewater, this study prepared novel fiber absorbents using melt-blow polypropylene (PP) melt as a matrix, as well as acrylic acid (AA) and maleic anhydride (MAH) as functional monomers. The modification conditions were studied to optimize the double-initiation, continuous-suspension grafting process, and then functional fibers were prepared by melt-blown spinning the modified PP. The results showed that the optimum modification conditions were as follows: a 3.5 wt% interfacial agent, 8 mg/L of dispersant, 80% monomer content, a 0.8 mass ratio of AA to MAH, a 1000 r/min stir speed, 3.5 wt% initiator DBPH grafting at 130 °C for 3 h, and 1 wt% initiator BPO grafting at 90 °C for 2 h. The highest grafting rate of the PP-g-AA-MAH was 31.2%, and the infrared spectrum and nuclear magnetic resonance spectroscopic analysis showed that AA and MAH were successfully grafted onto PP fiber. This modification strategy also made the fibers more hydrophilic. The adsorption capacity of the PP-g-AA-MAH fibers was highly dependent on pH, and the highest indigo adsorption capacity was 110.43 mg/g at pH 7. The fiber adsorption capacity for indigo increased rapidly before plateauing with increasing time or indigo concentration, and the experimental data were well described in a pseudo-second-order kinetic model and a Langmuir isothermal adsorption model. Most impressively, the modified fiber adsorption capacity for indigo remained as high as 91.22 mg/g after eight regeneration and reuse cycles. In summary, the PP-g-AA-MAH fibers, with excellent adsorption-desorption characteristics, could be readily regenerated and reused, and they are a promising material for the removal of indigo from wastewater.

Charge transfer-driven enhanced lithium extraction using poly(acrylic) acid-modified layered double hydroxide

This study presents an advanced strategy for developing a novel poly(acrylic) acid-modified layered double hydroxide (PAA@LDH) for enhanced lithium adsorption. The optimal modification conditions include the use of a 2.5 % PAA solution in deionized water, an LDH powder dosage of 90 mL/g, and direct mixing at 333 K. Under these conditions, additional negatively charged functional groups were introduced into the material structure, thereby improving charge transfer, increasing electron cloud density, and lowering equipotential charge, as determined by DFT calculations. Consequently, the modified adsorbent exhibited a substantial rise in lithium adsorption capacity, increasing from 2.08 mg/g to 3.41 mg/g in produced water with low lithium concentration. Adsorption kinetics were rapid, reaching equilibrium within 40 min, and the adsorption behavior conformed to the Langmuir isotherm model. Besides, the adsorbent exhibited excellent selectivity for Li+ ions and maintained its performance at approximately 3.40 mg/g over seven cycles when regenerated under neutral conditions. The findings establish a robust framework for designing innovative adsorbent systems for lithium recovery from aqueous sources like produced water.

A comparison of three modification methods for polyvinylidene fluoride membrane grafting

Abstract UV-induced covalent bonding, UV-benzophenone (BP) embedding, and ozone-activated grafting methods were respectively used to graft 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) on polyvinylidene fluoride (PVDF) hollow fiber membrane surfaces via orthogonal test. The rejection rate, permeating flux, and pure water flux were chosen as comprehensive evaluation indexes to optimize the modification conditions. The optimal experimental conditions for UV-induced covalent bonding, UV-BP embedding, and ozone-activated grafting methods were obtained. Subsequently, three membranes were prepared by these three methods under their optimal modification conditions to compare their properties. The PVDF-g-AMPS-2 membrane obtained by the UV-BP embedding method exhibited the highest hydrophilicity and lipophobicity, and its water and underwater oil contact angles were respectively 66.0° and 146.6°. Besides, The PVDF-g-AMPS-2 membrane can resist the adhesion of oil with the underwater oil adhesion force of zero. What’s more, the PVDF-g-AMPS-2 membrane possessed the largest pure water flux (544.5 L/(m2·h·bar)), permeation flux (66.5 L/(m2·h·bar)), and recovered flux (205.7 L/(m2·h·bar)). By comparison, UV-BP embedding with simpler procedures can fabricate the AMPS modified PVDF membrane with superior performance, which has better application prospects in industrial scale-up production.

Synthesis and Characterization of Emulsifiers Based on the Maillard Reaction and Its Application in Stabilized DHA Algal Oil Nanoemulsions.

The aim of this study was to optimize the formation of sodium caseinate (CS) and gum arabic (GA) complexes through the Maillard reaction and to evaluate their effectiveness in improving the emulsification properties and stability of docosahexaenoic acid (DHA) nanoemulsions. First, the best target polysaccharides were selected, and the best modification conditions were determined using orthogonal experiments. Secondly, the response surface experiments were used to optimize the preparation process of the emulsion. The stability, in vitro digestion characteristics, and rheological characteristics of the emulsion prepared by means of CS-GA were compared with the emulsion prepared using a whey protein isolate (WPI). After the orthogonal test, the optimal modification conditions were determined to be a reaction time of 96 h, a CS-GA mass ratio of 1:2, a reaction temperature of 60 °C, and a degree of grafting of 44.91%. Changes in the infrared (IR), Raman, ultraviolet (UV), and endogenous fluorescence spectra also indicated that the complex structure was modified. The response surface test identified the optimal preparation process as follows: an emulsifier concentration of 5 g/L, an oil-phase concentration of 5 g/L, and a homogenization frequency of five, and the emulsion showed good stability. Therefore, the use of a nanoemulsion as a nanoscale DHA algal oil delivery system is very promising for extending the shelf life and improving the stability of food.

Influence of Hydrothermal Modification on Adsorptive Performance of Clay Minerals for Malachite Green.

Artificially modified adsorbing materials mainly aim to remedy the disadvantages of natural materials as much as possible. Using clay materials such as rectorite, sodium bentonite and metakaolinite (solid waste material) as base materials, hydrothermally modified and unmodified materials were compared. CM-HT and CM (adsorbing materials) were prepared and used to adsorb and purify wastewater containing malachite green (MG) dye, and the two materials were characterized through methods such as BET, FT-IR, SEM and XRD. Results: (1) The optimal conditions for hydrothermal modification of CM-HT were a temperature of 150 °C, a time of 2 h, and a liquid/solid ratio 1:20. (2) Hydrothermal modification greatly increased the adsorptive effect. The measured maximum adsorption capacity of CM-HT for MG reached 290.45 mg/g (56.92% higher than that of CM). The theoretical maximum capacity was 625.15 mg/g (186.15% higher than that of CM). (3) Because Al-OH and Si-O-Al groups were reserved in unmodified clay mineral adsorbing materials with good adsorbing activity, after hydrothermal modification, the crystal structure of the clay became loosened along the direction of the c axis, and the interlayer space increased to partially exchange interlayer metal cations connected to the bottom oxygen, giving CM-HT higher electronegativity and creating more crystal defects and chemically active adsorbing sites for high-performance adsorption. (4) Chemical adsorption was the primary way by which CM-HT adsorbed cationic dye, while physical adsorption caused by developed pore canal was secondary. The adsorption reaction occurred spontaneously.

Comparative Study on the Emulsification of Octenyl Succinic Anhydride Modified Sweet Potato Starch: As Macromolecular and Particulate Stabilizers

AbstractSweet potato is one of the essential starch materials for food and feed world widely. However, its application is limited by the low viscosity and poor stability of native starches. Herein, sweet potato starch is modified by octenyl succinic anhydride (OSA) in the aqueous system. The optimization for esterification is studied using response surface methodology. The characteristics of OSA‐modified sweet potato starch are investigated, and its emulsifying properties as macromolecular and particulate stabilizers in the oil‐in‐water systems are compared. The optimal process conditions for OSA modification are: reaction time 4.0 h, temperature 38.8 °C, pH of the reaction system 8.2, starch concentration 32.2%, OSA amount 3.0%. The degree of substitution is 0.0185, and reaction efficiency is 79.7% under the optimum conditions. The new peaks at 1725 and 1573 cm−1 are observed by Fourier transform infrared spectroscopy. Compared with native starch, OSA‐modified sweet potato starch exhibits higher viscosities, improved paste clarity, and decreased retrogradation. The confocal laser scanning microscope results show that the gelatinized starch macromolecule and ungelatinized starch particles can arrange at the water–oil interface. The OSA‐modified sweet potato starch is both an effective macromolecular emulsifier and a particulate stabilizer, effectively stabilizing oil‐in‐water emulsions.

High-performance and economic biodegradable composites based on polybutylene adipate terephthalate and modified lignin

Polybutylene adipate terephthalate (PBAT) is a biodegradable polymer with promising properties, but its wide-spread application is limited by factors such as high cost, suboptimal mechanical characteristics, and slow biodegradation rate. In this study, these limitations are addressed by incorporating low-cost lignin, modified with an isocyanate compound, into PBAT via an extrusion process. By investigating the effects of varying isocyanate content on the lignin surface, the optimal modification conditions at room temperature are identified over 48 h. Additionally, the maximum lignin content (5 wt%) is determined within the composite to achieve a balance between mechanical, thermal, and biodegradation properties while also considering the economic and environmental feasibility of the polymer composite. The research delved into the examination of both the minimum selling price (MSP) and global warming potential (GWP) for all PBAT-mLigA composites. The optimized PBAT-mLigA composites exhibited a notable reduction of up to 7% in both MSP and GWP when compared to pure PBAT. The predominant determinants influencing the economic and environmental potentials of these composites are the pricing of PBAT and the ratio in which it is incorporated into the proposed composites.

Сорбция ионов Cu(II) и Fe(II) хлопковой целлюлозой, модифицированной диэтилентриамином

The authors have developed new effective sorbent based on chemically modified cotton cellulose. The modification process consists of two stages, including sequential treatment of cellulose with epichlorohydrin and diethylene triamine. The authors present 
 the optimal modification conditions for the obtained sorbent. It allows ones’ to achieve the highest values of sorption capacity for the extraction of iron(II) and copper(II) ions from aqueous solutions. The authors investigated the kinetics and equilibrium of heavy metal ion sorption in the system "cellulose sorbent - aqueous solution of metal sulphate" for original and modified cotton cellulose. Processing of the kinetic experiment results indicates that the kinetics of metal ion sorption is described most correctly in the framework of the pseudo-second-order kinetics model. Isotherms of heavy metal ions sorption clearly indicate the growth of sorption capacity for the modified sorbent in comparison with the original one. Processing of experimental isotherms within the Langmuir model made it possible to determine the values of the maximum sorption capacity (A∞) of original and modified with diethylenetriamine cotton cellulose with respect to Cu(II) and FE(II) ions. It was found that the A∞ of the modified sorbent was about 3 times higher than the ultimate sorption capacity of original cotton cellulose towards iron(II) and Cu(II) IONS. Comparison of IR spectra of the original cellulose samples and cellulose treated with diethylenetriamine indicates the changes that occurred during chemical modification. The paper presents SEM images showing the changes in the surface structure of the modified sorbent compared to the original one.

Cu(II) AND Fe(II) ION SORPTION BY COTTON CELLULOSE MODIFIED WITH DIETHYLENETRIAMINE

The authors have developed new effective sorbent based on chemically modified cotton cellulose. The modification process consists of two stages, including sequential treatment of cellulose with epichlorohydrin and diethylene triamine. The authors present 
 the optimal modification conditions for the obtained sorbent. It allows ones’ to achieve the highest values of sorption capacity for the extraction of iron(II) and copper(II) ions from aqueous solutions. The authors investigated the kinetics and equilibrium of heavy metal ion sorption in the system "cellulose sorbent - aqueous solution of metal sulphate" for original and modified cotton cellulose. Processing of the kinetic experiment results indicates that the kinetics of metal ion sorption is described most correctly in the framework of the pseudo-second-order kinetics model. Isotherms of heavy metal ions sorption clearly indicate the growth of sorption capacity for the modified sorbent in comparison with the original one. Processing of experimental isotherms within the Langmuir model made it possible to determine the values of the maximum sorption capacity (A∞) of original and modified with diethylenetriamine cotton cellulose with respect to Cu(II) and FE(II) ions. It was found that the A∞ of the modified sorbent was about 3 times higher than the ultimate sorption capacity of original cotton cellulose towards iron(II) and Cu(II) IONS. Comparison of IR spectra of the original cellulose samples and cellulose treated with diethylenetriamine indicates the changes that occurred during chemical modification. The paper presents SEM images showing the changes in the surface structure of the modified sorbent compared to the original one.

Study of the Effect of NaOH Treatment on the Properties of GF/VER Composites Using AE Technique.

The purpose of this study is to use acoustic emission (AE) technology to explore the changes in the interface and mechanical properties of GF/VER composite materials after being treated with NaOH and to analyze the optimal modification conditions and damage propagation process. The results showed that the GF surface became rougher, and the number of reactive groups increased after treating the GF with a NaOH solution. This treatment enhanced the interfacial adhesion between the GF and VER, which increased the interfacial shear strength by 25.31% for monofilament draw specimens and 27.48% for fiber bundle draw specimens compared to those before the GF was modified. When the modification conditions were a NaOH solution concentration of 2 mol/L and a treatment time of 48 h, the flexural strength of the GF/VER composites reached a peak value of 346.72 MPa, which was enhanced by 20.96% compared with before the GF was modified. The process of damage fracture can be classified into six types: matrix cracking, interface debonding, fiber pullout, fiber relaxation, matrix delamination, and fiber breakage, and the frequency ranges of these failure mechanisms are 0~100 kHz, 100~250 kHz, 250~380 kHz, 380~450 kHz, 450~600 kHz, and 600 kHz and above, respectively. This paper elucidates the fracture process of GF/VER composites in three-point bending. It establishes the relationship between the AE signal and the interfacial and force properties of GF/VER composites, realizing the classification of the damage process and characterizing the mechanism. The frequency ranges of damage types and failure mechanisms found in this study offer important guidance for the design and improvement of composite materials. These results are of great significance for enhancing the interfacial properties of composites, assessing the damage and fracture behaviors, and implementing health monitoring.

Chitosan-modified iron fillings materials for remediation of arsenic-contaminated soil

Arsenic (As) contamination of soils adversely affects human health and ecosystems and is an environmental issue of serious concern worldwide. Efficient and economical remediation methods are urgently needed. In this research, a chitosan-modified scrap iron filings (CFF) composite was prepared by using industrial scrap iron filings and chitosan to stabilize As-contaminated soil. The optimal modification conditions were explored, and CFF was applied to As-contaminated soil to investigate its remediation effect and stabilization mechanism. The results showed that the optimal preparation conditions of CFF were chitosan concentration of 3.75 % (w/w), chitosan to scrap iron filings ratio of 1:1, optimal modification temperature of 40 °C, iron filings particle size of 35–80 mesh, and 10 % glutaraldehyde crosslinking for 6 h, and the stabilization efficiency of As was 73.98 %. The adsorption behavior of CFF was consistent with the pseudo-second-order kinetic model and the Langmuir isotherm model, and the best adsorption effect was achieved at pH = 5–6. The possible mechanisms of As stabilization by CFF were surface complexation, hydrogen bonding synergy, precipitation, electrostatic attraction, and van der Waals forces.

Study on the adsorption performance of amoxicillin by hydrothermally modified coconut shell activated carbon

AbstractBACKGROUNDUtilizing biowaste‐derived carbon (C) materials to remediate antibiotic‐rich wastewater has considerable ecological significance in the broader ecological cycle. In this study, coconut shell activated carbon (AC) was modified using a potassium hydroxide (KOH) hydrothermal method, and the influence of modified coconut shell AC on the adsorption of amoxicillin at different particle sizes and treatment temperatures was investigated. In addition, the adsorption kinetics of amoxicillin on different modified coconut shell AC was studied.RESULTSThe study found that unmodified coconut shell AC itself had a certain adsorption capacity for amoxicillin, with a maximum adsorption capacity of 22.43 mg g−1. After hydrothermal‐alkali modification, the adsorption capacity of coconut shell AC for amoxicillin was greatly improved, with an adsorption capacity increase of 221%. In addition, the adsorption kinetic fitting results showed that the adsorption process of amoxicillin on coconut shell AC was more consistent with the pseudo‐second‐order kinetic model.CONCLUSIONThe optimal modification condition for coconut shell AC was to treat coconut shell AC with a particle size of 80–120‐mesh at 160 °C. The findings of this study could offer a green and environmentally sustainable approach for amoxicillin‐contaminated wastewater treatment, and also could provide a certain theoretical basis for the application of biowaste resources in organic wastewater treatment. © 2024 Society of Chemical Industry (SCI).

Dual-grating waveguide coupler biosensor for the real-time determination of human immunoglobulin M (IgM) antibodies

A dual-grating waveguide coupler biosensor was developed to detect human immunoglobulin M (IgM) antibodies with modification procedures using (3-aminopropyl)triethoxysilane (APTES) as the self-assembled monolayer were optimized. The average bulk sensitivity and optimal resolution were 43.84 ± 1.15 RIU−1 and 6.18 × 10−6 RIU, respectively. Due to the photocatalytic property of TiO2, ultraviolet treatment for 7.5 min was used to form the hydroxyl groups on TiO2 surface. APTES immobilized the biomolecules via chemical bonding; the optimal APTES modified parameters were 2% (v/v) for 0.5 h at 80 °C. Glutaraldehyde (GA) immobilized the protein A without activating carboxyl groups of protein A. The optimal GA modified conditions were 2.5% (v/v) for 48 min. Protein A immobilized the capture antibody directionally, the fragment antigen binding (Fab) region of the capture antibody was more completely exposed to improve the detection effect. Using the optimal modification conditions, the limit of detection for human IgM immunoassay was 2.67 × 10−8 ± 1.18 × 10−8 g/mL. Furthermore, this biosensor was demonstrated to determine the concentration of human IgM within 1 h and has potential for commercialization.

Highly efficient capture of E. coli using amidoximated polyacrylonitrile nanofiber membrane immobilized with reactive green 19 dye/polyhexamethylene biguanide: Antibacterial and cytotoxicity studies

In this study, we synthesized an amidoximated polyacrylonitrile nanofiber membrane (P-Oxime). Subsequently, we grafted reactive green 19 (RG19) dye onto its surface, resulting in the formation of the P-Oxime-RG19 membrane. Further enhancement was achieved by physically attaching poly(hexamethylene biguanide) hydrochloride (PHMB) to the P-Oxime-RG19 membrane, leading to the formation of the P-Oxime-RG19-PHMB membrane. Extensive characterization of the nanofiber membranes was conducted, focusing on crucial physical and mechanical properties such as functional group content, morphology, and thermostability. The optimization of various modification conditions, including initial dye and PHMB concentrations, duration, temperature, and nitrile group conversion to oxime concentrations, played a pivotal role in achieving superior antibacterial performance in P-Oxime-RG19-PHMB nanofiber membranes. In-depth analyses involved the application of kinetic and equilibrium thermodynamic models to unravel the modification processes of RG19 dye and PHMB in the nanofiber membranes. Under the carefully tuned optimal modification conditions, the P-Oxime-RG19-PHMB nanofiber membrane exhibited remarkable antibacterial efficacy, achieving nearly 100% disinfection of E. coli. In addition to exploring its antimicrobial capabilities, we thoroughly examined the repeatability and biocompatibility of the nanofiber membranes. The results indicated not only the P-Oxime-RG19-PHMB nanofiber membrane was a highly promising antibacterial material but also highlighted its potential for diverse applications, particularly in food and textile fabrication, owing to its exceptional performance and suitability.

Influence of Silane Coupling Agent and Anionic Dispersant on the Dispersion Effect of Silicon Carbide Particles.

Silicon carbide (SiC), as a widely used material, has great properties. To improve the flowability of ultrafine silicon carbide slurry, this study used sodium humate, tetramethylammonium hydroxide (TMAH), and N-(β-monoaminoethyl)-γ-aminopropyltrimethyl(ethoxysilane) (KH792) to modify the ultrafine silicon carbide powder produced by Qingzhou Micro Powder Company. The effects of different modifiers on improving the flowability of ultrafine silicon carbide slurry were investigated by means of viscosity tests, sedimentation experiments, and SEM observations. Their modification mechanisms were investigated by means of zeta potential tests, XPS tests, and so on. In this paper, the initial modification of SiC was carried out with KH792, followed by the secondary modification with anionic and cationic modifiers (tetramethylammonium hydroxide and sodium humate), and the optimal modification conditions were investigated by means of a viscosity test, which showed that the lowest viscosity of the modified SiC reached 0.076 Pa·s and that the absolute maximum value of the zeta potential increased from 47.5 at the time of no modification to 63.7 (maximum values) at the time of modification. This means it has an improved surface charge, which improves dispersion. The adsorption results of the modifier on the silicon carbide surface were also demonstrated by the XPS test results.

Effect of various oligosaccharides on casein solubility and other functional properties: Via Maillard reaction

This study explored the improvement of casein (CN)’s properties by conjugating it with oligosaccharides, namely, fructooligosaccharide (FOS), galactooligosaccharide (GOS), isomaltooligosaccharide (IMO), and xylo-oligosaccharide (XOS) via Maillard reaction to identify the most optimal oligosaccharides and modification conditions. The degree of grafting was 30.5 ± 0.41 % for CN-FOS, 33.7 ± 0.62 % for CN-GOS, 38.9 ± 0.51 % for CN-IMO, and 43.7 ± 0.54 % for CN-XOS. With the degree of grafting rising, more oligosaccharides were conjugated, causing greater changes in CN properties. The CN-XOS underwent significant alterations, as the introduction of oligosaccharides led to a decrease in particle size by around 51 nm. Furthermore, the hydroxyl groups caused a reduction in surface hydrophobicity, which in turn decreased the proportion of hydrophobic groups. The solubility of CN-XOS increased significantly at pH 3, by approximately 30.99 %. Additionally, the conjugation of oligosaccharides substantially boosted the rates of DPPH, ABTS, and -OH radical scavenging by 4.61 times, 2.20 times, and 2.58 times, respectively, and also improved the thermal stability of the modified CN. Moreover, the process lowered the protein digestibility, possibly enhancing its applicability as an active substance transporter. This research offers additional theoretical backing for altering CN with oligosaccharides and implementing it in the food and pharmaceutical sectors.