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This study investigates the impact of acetylation treatment on Enterolobium cyclocarpum (Parota) starch, focusing Morphological, Physico‐chemical and thermal impact induced by varying acetylation levels. The research employed scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) to examine the structural and thermal alterations resulting from acetylation. These analyses also evaluated the starch's thermal stability. Through titration, the degree of substitution and acetyl group content were quantified, demonstrating significant morphological transformations in the starch, such as increased particle size and the appearance of surface cracks on the granules. The study revealed that the degree of substitution, which changes with the duration of acetylation, markedly influences the starch's physicochemical properties, including hydrophobicity and thermal stability. Initially, acetylation reduced the gelatinization temperature, suggesting a decrease in the energy required for gelatinization. Over longer acetylation periods, however, the gelatinization temperature increased, likely due to enhanced crystallinity or molecular reorganization. These findings indicate that acetylated Parota starch has potential applications in the food industry as an encapsulating agent and in the thermoplastics industry as a plasticizer, dependent on the level of acetylation. This research underscores the utility of specific chemical modifications to adapt starch properties for various industrial applications. [ABSTRACT FROM AUTHOR]

We presents an innovative approach to addressing the mechanical properties limitations of fluororubber (FKM) in the industrial field. A novel functionalized nano-silica spheres (SiO2), grafted with amino groups, were constructed by utilizing chemical grafting. The surface modification of the nanosilica microspheres enables the formation of C=N bonds between the amino-functionalized nanosilica microspheres and FKM promoting high dispersion and strong interfacial bonding of SiO2, resulting in an exceptional mechanical enhancement function for FKM composite. Compared to original FKM, the FKM/SM-A-10 composite demonstrates remarkable improvements in both tensile strength and hardness by 242% and 49%, respectively. Additionally, there is a notable 40% enhancement in thermal conductivity of the FKM/SM-A-10 composite. This straightforward and efficient manufacturing approach for achieving high-performance FKM proves to be a valuable and practical foundation for industrial design. [ABSTRACT FROM AUTHOR]

Hydrophobic coatings were fabricated on 400-mesh 304 stainless steel by combining hydrothermal treatment and chemical modification. The hydrophobicity of the surfactant coatings was evaluated. The fabricated coatings were characterized by scanning electron microscopy, contact angle measurements and X-ray diffraction. The results revealed that a hydrophobic coating with a water contact angle of 154∘ could be successfully synthesized under specific conditions: a concentration of 0.005mol⋅L−1 C12H25SO4Na and subsequent modification with a 1mol⋅L−1 ethanol stearate solution for 24h. This outcome highlights the potential of this methodology for producing highly efficient hydrophobic coatings for stainless steel mesh substrates. [ABSTRACT FROM AUTHOR]

Anti-wear and anti-oxidation abilities are two key properties of lubricants that play a crucial role in ensuring long-term stable equipment operation. In this study, we aimed to develop a base oil with good anti-oxidation and anti-wear properties for use under extreme pressure. The as-prepared metallocene polyalphaolefin (mPAO) was chemically modified using the trifluoromethanesulfonic acid (TfOH) catalysis through an alkylating reaction with triphenyl phosphorothioate (TPPT). During the experiments, when the reaction temperature exceeded 70 °C or the concentration of TfOH exceeded 2.67%, the β -scission reaction in the alkylation process became significantly more pronounced. The physical and chemical properties of TPPT-modified mPAO (T-mPAO) were evaluated by nuclear magnetic resonance spectroscopy, Fourier trans-form infrared spectroscopy, gel–permeation chromatography, and ASTM standards. T-mPAO showed significantly improved antioxidant capacity, with the initial oxidation temperature increasing by 32 °C compared to the base oil, and it exhibited the slowest increase in acid number in the 96-h oven oxidation test. The tribological tests showed that T-mPAO had the lowest friction coefficient, wear track, and wear rate (72.7% lower than that of mPAO) as well as the highest PB (238 kg) and PD (250 kg) among all tested samples. Compared to mPAO, the average friction coefficient of TPPT-modified mPAO in the four-ball friction test was reduced by 30.5%, and by 16.4% in the TE77 reciprocating friction test. Based on the experimental results, T-mPAO had strong anti-oxidation ability and excellent lubricating performance.The successful synthesis of multifunctional mPAO has enabled lubricant base oil additization, making it possible to use it in more demanding work scenarios, greatly broadening its application scope and making lubricant formulation blending more flexible. [ABSTRACT FROM AUTHOR]

Rapid control of the content of Parkinson's drugs in biological fluids and pharmaceutical formulations is of great importance because changes in the concentration of these drugs affect their bioavailability and biopharmaceutical properties. Therefore, we presented a simple and convenient method for the ratiometric detection of carbidopa and levodopa for carbon dots (CDs) dual‐fluorescent emission. Dual‐emission CDs were prepared from chitosan using a microwave method, following which the surface was chemically modified with terephthalaldehyde. CDs had two strong well‐separated peaks at 445 and 510 nm. The relative measurement of carbidopa and levodopa was based on the static extinction of CDs at 445 nm and increase at 510 nm, respectively. The linear range for carbidopa measurement was 2.5–300 nM, with a limit of detection (LOD) of 2.1 nM, and a relative standard deviation (RSD) of 1.68%. Further, the linear range for levodopa measurement was equal to 3.0–400 nM, with LOD and RSD% of 2.8 nM and 3.5%, respectively. Also, selectivity of ratiometric sensor in the presence of interferences was investigated, which showed that the recovery of carbidopa and levodopa in serum and urine samples has changed between 96.80% and 116.24% with RSD% 0.11–0.77. CDs also provided good results for the determination of carbidopa and levodopa in real samples, and had high selectivity in the presence of possible interferences. [ABSTRACT FROM AUTHOR]

BACKGROUND: Garlic is a promising source of antimicrobial peptide separation, and chemical modification is an effective method for activity improvement. The present study aimed to improve the antifungal activity of a peptide extracted from garlic. Chemical modifications were conducted, and the structure–activity relationship and antifungal mechanism were investigated. RESULTS: The results indicated that the cationic charge induced by Lys residue at the N‐terminal was important for the antimicrobial activity, and the modified sequence exhibited significant antifungal activity with low mammalian toxicity and a low tendency of drug resistance (p < 0.05). The structure–activity relationship analysis revealed that the modified active peptide had a predominant α‐helical structure and an inner cyclic correlation. Transcriptomic analysis showed that peptide KMLKKLFR (Lys‐Met‐Leu‐Lys‐Lyse‐Leu‐Phe‐Arg) affected the rRNA processing and carbon metabolism process of Candida albicans. In addition, the membrane potential study indicated a non‐membrane destruction mechanism, and molecular docking analysis and a DNA interaction assay suggested promising inner targets. CONCLUSION: The results of the present study indicate that chemical modification by amino acid substitution was effective for antimicrobial activity improvement. The present study would benefit future antimicrobial peptide development and suggests that garlic is a great source of antibacterial peptides and peptide template separations for coping with antibiotic resistance. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The synthesis of Cu2O nanoparticles (NPs) through the reduction of copper hydroxide using ascorbic acid and then Cu2O NPs modified with triacetoxy(vinyl)silane (TVAS) (m-Cu2O) by solution method were achieved. FTIR analysis of the unmodified Cu2O NPs and m-Cu2O NPs revealed the presence of absorption characteristics corresponding to Cu–O–Si linkages in the FTIR spectra of m-Cu2O NPs, which is strong evidence that the Cu2O NPs have been successfully modified. The characteristics and properties of m-Cu2O NPs were determined and compared to those of the u-Cu2O NPs. The results indicated that the modification process had an insignificant effect on the crystal structure and morphology of Cu2O NPs. X-ray diffraction analysis indicated that the crystal grain size of m-Cu2O NPs slightly increased, measuring 41.04 nm compared to 38.36 nm for the u-Cu2O NPs, this change was minor. However, the m-Cu2O NPs demonstrated enhanced dispersion into acrylic emulsion polymer, resulting in improved abrasion resistance and thermal stability of the acrylic coating. In comparison with an acrylic coating filled with the u-Cu2O NPs, the coating filled with m-Cu2O NPs exhibited a 70% increase in abrasion resistance and better thermal stability. Importantly, the antibacterial performance against E. coli and S. aureus of acrylic coating filled with m-Cu2O NPs was similar to that of the u-Cu2O NPs nanocomposite coating. These findings underscore the versatility and benefits of chemical modification in enhancing specific properties of the acrylic coating without compromising antibacterial efficacy. [ABSTRACT FROM AUTHOR]

The post-treatment of heavy metal-enriched plants in mining areas and the purification of ammonia and nitrogen pollution in water bodies are significant for the ecological environment of ionic rare earth mining areas. Herein, we focused on the biochar production potential of Dicranopteris pedata, characterizing biochar prepared by an oxidative modification process and an iron modification process. We conducted adsorption experiments to comparatively investigate the adsorption performance of biochar on NH4+ and studied the fertilizer application and migration toxicity of the adsorbed biochar for rare earth elements (REEs). Results indicated that ~332.09 g of biochar could be produced per unit area of D. pedata under 100% clipping conditions. The Brunauer–Emmett–Teller (BET) specific surface area of oxidized biochar (H2O2BC) increased, and the pore size of iron-modified biochar increased. The adsorption behavior of biochar toward NH4+ was well represented by the pseudo-second-order and Langmuir models. H2O2BC demonstrated the strongest adsorption of NH4+ with maximum theoretical equilibrium adsorption of 43.40 mg·g−1, 37.14% higher than that of pristine biochar. The adsorption process of NH4+ on biochar is influenced by various physicochemical mechanisms, including pore absorption, electrostatic attraction, and functional group complexation. Furthermore, the metal ions in the biochar did not precipitate during the reaction process. The adsorbed NH4+ biochar promoted the growth of honey pomelo without risking REE pollution to the environment. Therefore, it can be applied as a nitrogen-carrying rare earth fertilizer in low rare earth areas. This study provides a theoretical basis and technical support for the phytoremediation post-treatment of rare earth mining areas and the improvement of ammonia nitrogen wastewater management pathways in mining areas. [ABSTRACT FROM AUTHOR]

This article succinctly outlines the key points of the emergence and development of methods for chemical modification of the surface of inorganic substrates. It is shown that the assumption of the presence of chemically active functional groups on such surfaces arose relatively recently, although the first experience of practical application was carried out in the middle of the 19th century. The main stages in the development of the chemistry of surface compounds are traced. [ABSTRACT FROM AUTHOR]

Herein, the cost-effective utilization of biosorption for toxic pollutant removal was investigated, with a specific emphasis on enhancing mushroom-based biosorbents for the decontamination of heavy metals-polluted aqueous environments. Firstly, Oyster mushrooms (Pleurotus ostreatus) collected from Bajaur, Khyber Pakhtunkhwa, Pakistan, underwent thorough cleaning, followed by air-drying for 2–3 weeks to produce a fine powder. The obtained powder was subjected to thermal modification through heating at 400°C/1 h, and a portion of it was additionally modified using potassium hydroxide (KOH). This process resulted in three distinct materials: untreated dried mushroom (AM), thermally modified mushroom (TMM), and chemically modified mushroom (CMM), and their chemical compositions were assessed using Fourier Transform Infrared (FTIR) spectroscopy. Subsequently, the resulting materials were employed as bioadsorbents for the elimination of toxic Fe(III) ions from aqueous media. Various experimental variables, including solution pH, temperature, contact time, pollutant concentration, and adsorbent amount were varied to investigate their impact on adsorption. Analysis using an atomic absorption spectrophotometer (AAS) demonstrated exceptional Fe(III) removal capacities of mushrooms, achieving a removal extent of 29.99 mg/g at 303 K, pH 6.0, and an adsorbent dosage of 0.1 g/L, resulting in a remarkable 99.97% removal efficiency. The type of adsorbent significantly affected the extent of adsorption. Furthermore, thermodynamic analysis revealed that adsorption was spontaneous and exothermic. The adsorption data were evaluated using Langmuir, Freundlich, and Temkin isotherms, with the pseudo-second-order reaction kinetics providing the best fit, suggesting that chemisorption predominates the surface adsorption of Fe(III). This study highlights the potential of mushroom-based biosorbents as eco-friendly and effective materials for purifying water contaminated with toxic pollutants. [ABSTRACT FROM AUTHOR]

The synthesis and modification of peptides occupy a unique position in the field of drug development, and the functionalization of amino acids is a valuable strategy as an alternative to peptide modification. Currently, the development of tyrosine (Tyr) as a target amino acid is a major challenge in the field of chemistry. Herein, we report an electrochemical radical coupling reaction of labeling tyrosine-containing active drugs and peptides with thiocarbamate derivatives for the first time. This tri-component, one-pot reaction can be performed smoothly under simple, gentle, and clean electrochemical conditions and is suitable for the functionalization of various Tyr-containing drug molecular derivatives and peptides. [ABSTRACT FROM AUTHOR]

Messenger RNA (mRNA) is a type of RNA that carries genetic information from DNA to the ribosome, where it is translated into proteins. mRNA has emerged as a powerful platform for development of new types of medicine, especially after the clinical approval of COVID-19 mRNA vaccines. Chemical modification and nanoparticle delivery have contributed to this success significantly by improving mRNA stability, reducing its immunogenicity, protecting it from enzymatic degradation, and enhancing cellular uptake and endosomal escape. Recently, substantial progresses have been made in new modification chemistries, sequence design, and structural engineering to generate more stable and efficient next-generation mRNAs. These innovations could further facilitate the clinical translation of mRNA therapies and vaccines. Given that numerous review articles have been published on mRNA nanoparticle delivery and biomedical applications over the last few years, we herein focus on overviewing recent advances in mRNA chemical modification, mRNA sequence optimization, and mRNA engineering (e.g., circular RNA and multitailed mRNA), with the aim of providing new perspectives on the development of more effective and safer mRNA medicines. [ABSTRACT FROM AUTHOR]

Resistant starch from plantain (Macho Musa paradisiaca L.) and banana (Roatan Musa sapientum L.) varieties was chemically modified by crosslinking using epichlorohydrin (EPI). These modified starches were subjected to in vitro digestibility studies using the Englyst method to determine the content of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). The thermal stability of these crosslinked starches was evaluated by gelatinization and retrogradation analyses, and their enthalpies were determined using differential scanning calorimetry (DSC). Additionally, their functional properties were evaluated. Chemical modification with EPI significantly increased the RS content in both starch varieties compared to that in native starch. The enthalpy and gelatinization temperature decreased in the EPI-modified starches of both varieties, indicating lower thermal stability during the gelatinization process compared to that of native starch. In general, both varieties of crosslinked plantain starch had lower viscosity (0.43 Pa*s) than did native starch (0.58 Pa*s). The results indicates that this starch crosslinked with EPI constitutes an alternative for use in food for people with health problems such as high cholesterol levels or postprandial insulin concentrations. [ABSTRACT FROM AUTHOR]

Olive mill waste (olive pomace, OP, and olive stone, OS) was used in this work to produce adsorbents for the removal of five phenolic acids typically found in olive mill wastewater. OP and OS were subjected to different treatments (combined or not) that were chemically modified (NaOH) or physically modified by two different methods, incipient wetness impregnation (IWI) and hydrothermal deposition (HD), and even biochar production obtaining a total of 16 materials. The materials were characterized by different analytical techniques such as N2 absorption, scanning electron microscopy, infrared spectroscopy, and pH zero-potential charge. The mixture of five phenolic acids was used to evaluate in batch conditions the adsorption capacity of the prepared materials. OS chemically modified with IWI (OSM-IWI) and OS biochar with HD (BOS-HD) presented better adsorption capacity at 157.1 and 163.6 mg/g of phenolic acids, respectively, from a total of 200 mg/g. For some materials, the surface area cannot be correlated with adsorption capacity, unlike pHzpc, where high values fit better adsorption rates. The infrared spectroscopy profile indicates the presence of O-H and N-H functional groups and, the last one, red-shifted in the IWI preparation compared to the HD one. In addition to this, the prepared material from olive mill waste can be suitably used for the mixture of phenolic compounds. [ABSTRACT FROM AUTHOR]

Purpose: In order to solve the key problem that the flotation tailings of collophanite are difficult to effectively utilize because of large discharge, fine particle size, and high loss on ignition, this study carried out an experimental study on the preparation of magnesium-based cementitious materials by roasting activation and chemical modification of phosphorus tailings. Method: The effects of the roasting temperature of phosphorus tailings, MgCl2 content,and water-cement ratio on the mechanical properties and microstructure of cementitious materials were studied by the method of controlled variables. Results: When the calcination temperature is 800 °C, the calcination time is 2 h, the dosage of MgCl2 is 8%, and the water-cement ratio is 0.1, the 7-day compressive strength of cementitious materials can reach 45. 21 MPa, which has good mechanical properties. The main hydration products are phase 518 and phase 318, which play a positive role in improving the strength of cementitious materials and promoting the strength of cementitious materials. Conclusion: This study makes full use of the natural endowment characteristics of high magnesium content in phosphorus tailings to prepare cementitious materials with excellent properties, which provides a new idea for the high-value utilization of phosphorus tailings. [ABSTRACT FROM AUTHOR]

The potato has recently attracted more attention as a promising protein source. Potato proteins are commonly extracted from potato fruit juice, a byproduct of starch production. Potato proteins are characterized by superior techno‐functional properties, such as water solubility, gel‐forming, emulsifying, and foaming properties. However, commercially isolated potato proteins are often denatured, leading to a loss of these functionalities. Extensive research has explored the influence of different conditions and techniques on the emulsifying capacity and stability of potato proteins. However, there has been no comprehensive review of this topic yet. This paper aims to provide an in‐depth overview of current research progress on the emulsifying capacity and stability of potato proteins and peptides, discussing research challenges and future perspectives. This paper discusses genetic diversity in potato proteins and various methods for extracting proteins from potatoes, including thermal and acid precipitation, salt precipitation, organic solvent precipitation, carboxymethyl cellulose complexation, chromatography, and membrane technology. It also covers enzymatic hydrolysis for producing potato‐derived peptides and methods for identifying potato protein–derived emulsifying peptides. Furthermore, it reviews the influence of factors, such as physicochemical properties, environmental conditions, and food‐processing techniques on the emulsifying capacity and stability of potato proteins and their derived peptides. Finally, it highlights chemical modifications, such as acylation, succinylation, phosphorylation, and glycation to enhance emulsifying capacity and stability. This review provides insight into future research directions for utilizing potato proteins as sustainable protein sources and high‐value food emulsifiers, thereby contributing to adding value to the potato processing industry. [ABSTRACT FROM AUTHOR]

Abstract The mung bean peel polysaccharide (MBP) extracted by hot water was chemically modified. By changing the dosage of phosphorylation reagent and acetylation reagent, three kinds of phosphorylated MBP ( P-MBP-1, P-MBP-2, P-MBP-3 ) and acetylated MBP ( AC 0.6-MBP, AC 1-MBP, AC 1.4-MBP ) with different degrees of substitution were prepared. By measuring the sugar content and substitution degree of the modified products, it was found that the amount of reagent had a certain effect on both of them. The modified products were determined by infrared spectrum and nuclear magnetic resonance. The results showed that the chemical modification was successful. The in vitro antioxidant capacity (·OH scavenging ability, O2 −·clearing ability, reducing capacity, resistance to lipid peroxidation) of seven polysaccharide were measured, which manifested that chemical modification could enhance the antioxidant ability of MBP to varying degrees, and the DS also had a certain impact on their antioxidant activity. This promoted the development of mung bean peel polysaccharide functional products and the utilization of mung bean peel resources.

Abstract Resistant starch from plantain (Macho Musa paradisiaca L.) and banana (Roatan Musa sapientum L.) varieties was chemically modified by crosslinking using epichlorohydrin (EPI). These modified starches were subjected to in vitro digestibility studies using the Englyst method to determine the content of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). The thermal stability of these crosslinked starches was evaluated by gelatinization and retrogradation analyses, and their enthalpies were determined using differential scanning calorimetry (DSC). Additionally, their functional properties were evaluated. Chemical modification with EPI significantly increased the RS content in both starch varieties compared to that in native starch. The enthalpy and gelatinization temperature decreased in the EPI-modified starches of both varieties, indicating lower thermal stability during the gelatinization process compared to that of native starch. In general, both varieties of crosslinked plantain starch had lower viscosity (0.43 Pa*s) than did native starch (0.58 Pa*s). The results indicates that this starch crosslinked with EPI constitutes an alternative for use in food for people with health problems such as high cholesterol levels or postprandial insulin concentrations. Graphical Abstract

Anthocyanins have attracted a lot of attention in the fields of natural pigments, food packaging, and functional foods due to their color, antioxidant, and nutraceutical properties. However, the poor chemical stability and low bioavailability of anthocyanins currently limit their application in the food industry. Various methods can be used to modify the structure of anthocyanins and thus improve their stability and bioavailability characteristics under food processing, storage, and gastrointestinal conditions. This paper aims to review in vitro modification methods for altering the molecular structure of anthocyanins, as well as their resulting improved properties such as color, stability, solubility, and antioxidant properties, and functional applications as pigments, sensors and functional foods. In industrial production, by mixing co-pigments with anthocyanins in food systems, the color and stability of anthocyanins can be improved by using non-covalent co-pigmentation. By acylation of fatty acids and aromatic acids with anthocyanins before incorporation into food systems, the surface activity of anthocyanins can be activated and their antioxidant and bioactivity can be improved. Various other chemical modification methods, such as methylation, glycosylation, and the formation of pyranoanthocyanins, can also be utilized to tailor the molecular properties of anthocyanins expanding their range of applications in the food industry. [ABSTRACT FROM AUTHOR]

Acylation is a common method for chemical modification of proteins, which can effectively improve the functional properties of proteins and has been widely used in food processing in recent years. The effect of acylation on protein modification is related to the degree of modification, and low degree of acylation modification can significantly improve the solubility, thermal stability, foaming and emulsifying properties, gelation properties, film-forming properties and nutritional quality of proteins. This paper reviews the effect of acylation modification on protein structure, physicochemical properties, and functional properties, as well as the application of acylated proteins in food and other fields. Hopefully, this review will provide a theoretical reference for protein modification research.

Abstract Background Polysaccharide from Garcinia mangostana rind has many biological activities and deserves further research. Methods The antioxidant properties of UAEE-GMRP, UAEE-GMRP-1 A, CM-30, and Ac-30 were evaluated through two different antioxidant activity experimental systems. Results The four polysaccharides had a better scavenging effect on hydroxyl radicals, while their inhibitory effect on lipid peroxidation was relatively weak. However, overall, the four polysaccharides showed a certain degree of potential application in the two antioxidant experiments mentioned above, especially the chemically modified polysaccharides from Garcinia mangostana rind, which effectively improved their antioxidant activity. This also indicates that chemical modification is a better method to improve polysaccharide activity. In addition, in these two antioxidant exploration experiments, carboxymethylated polysaccharide showed stronger activity compared to the other three polysaccharides. Conclusion The carboxymethylation modification may have great potential for application.

A new nickel plating process for diamond wire is explored to eliminate the negative impact of dispersants on the production process of diamond wires. The surface of of Ni-plated diamond particles was first hydroxylated with hydrogen peroxide, and then reacted with dimethyloctadecyl [3-trimethoxysilylpropyl] ammonium chloride to prepare positively charged diamond particles. Finally, the preparing process of diamond wires were optimized. Results show that the surface potential of diamond particles increases from −7.50 mV to 14.10 mV or above after reaction, up to 30.68 mV. The best preparing conditions are as follows: The mass ratio of raw sand to hydrogen peroxide is 2 to 1, with treating time of 1 h; The mass ratio of diamond particles to quaternary ammonium salts is 1 to 2, with treating time of 4 h. In the electroplating process, the diamond particles with chemically modified surface would uniformly migrate towards the cathode without dispersants, the sanding capacity of which could be increased by 20% or more.

Radix Paeoniae Alba is an important plant resource and valuable tonic in traditional Chinese medicine. The radix of Radix Paeoniae Alba is rich in starch. There are few reports of Radix Paeoniae Alba starch. In present study, the Radix Paeoniae Alba starch is extracted, citrate esterified starches are prepared, the starch‐based hydrogels are synthesized, and adsorptive properties are investigated. The investigation suggests that Radix Paeoniae Alba starch‐based adsorbent is promising as an efficient and sustainable adsorbent for copper ions and methylene blue removal; therefore, Radix Paeoniae Alba starch has an appealing application prospect in adsorption for scavenging metal ions and dyes from real complex waste liquid. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene (PDA) materials have always been a challenging issue. In this work, a series of diacetylene monomers (m-PCDA) containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid (PCDA) through the esterification or amidation reactions. The effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability, and the thermochromic mechanism of their corresponding polymers (m-PDA) were investigated and discussed in detail. The results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction, and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA materials. The thermochromic behavior of m-PDA depends on its melting process. The initial color-change temperature (blue to red) is determined by the onset melting temperature, and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting range. According to the proposed thermochromic mechanism of PDA, various new PDA materials with precise thermochromic temperatures and reversible thermochromic temperature ranges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene monomer. This work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials. [ABSTRACT FROM AUTHOR]

The perennial herb Aconitum sinomontanum Nakai (Ranunculaceae) has been utilized as a traditional oriental medicine in China for numerous years. The principal pharmacological constituent of A. sinomontanum, lappaconitine (LA), exhibits analgesic, anti-inflammatory, anti-tumor, anti-arrhythmic, and anti-epileptic activities. Due to its potent efficacy and non-addictive nature, LA is widely utilized in the management of cancer pain and postoperative analgesia. This review encompasses the research advancements pertaining to LA including extraction methods, separation techniques, pharmacological properties, chemical modifications, and clinical applications. Additionally, it offers insights into the potential applications and current challenges associated with LA to facilitate future research endeavors. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Increasing evidence has suggested that nanoplastic pollution has become a global concern. More importantly, transgenerational toxicity can be induced by nanoplastics at predicted environmentally relevant doses (ERDs). Considering that amino modification could increase nanoplastic toxicity, we compared transgenerational neurotoxicity between pristine polystyrene nanoparticle (PS-NP) and amino-modified PS-NP (NH2-PS-NP) in Caenorhabditis elegans. At 0.1–10 μg/L, NH2-PS-NP caused more severe transgenerational toxicity on locomotion and neuronal development. Accompanied with a difference in transgenerational neuronal damage, compared to PS-NP (10 μg/L), NH2-PS-NP (10 μg/L) induced more severe transgenerational activation of mec-4, crt-1, itr-1, and tra-3, which are required for the induction of neurodegeneration. Moreover, NH2-PS-NP (10 μg/L) caused more severe transgenerational inhibition in expressions of mpk-1, jnk-1, dbl-1, and daf-7 than PS-NP (10 μg/L), and RNA interference (RNAi) of these genes conferred susceptibility to the toxicity of PS-NP and NH2-PS-NP on locomotion and neuronal development. NH2-PS-NP (10 μg/L) further caused more severe transgenerational activation of germline ligand genes (ins-3, ins-39, daf-28, lin-44, egl-17, efn-3, and lag-2) than PS-NP (10 μg/L), and RNAi of these ligand genes caused resistance to the toxicity of PS-NP and NH2-PS-NP on locomotion and neuronal development. Our results highlighted more severe exposure risk of amino-modified nanoplastics at ERDs in causing transgenerational neurotoxicity in organisms. [ABSTRACT FROM AUTHOR]

Background: Polysaccharide from Garcinia mangostana rind has many biological activities and deserves further research. Methods: The antioxidant properties of UAEE-GMRP, UAEE-GMRP-1 A, CM-30, and Ac-30 were evaluated through two different antioxidant activity experimental systems. Results: The four polysaccharides had a better scavenging effect on hydroxyl radicals, while their inhibitory effect on lipid peroxidation was relatively weak. However, overall, the four polysaccharides showed a certain degree of potential application in the two antioxidant experiments mentioned above, especially the chemically modified polysaccharides from Garcinia mangostana rind, which effectively improved their antioxidant activity. This also indicates that chemical modification is a better method to improve polysaccharide activity. In addition, in these two antioxidant exploration experiments, carboxymethylated polysaccharide showed stronger activity compared to the other three polysaccharides. Conclusion: The carboxymethylation modification may have great potential for application. [ABSTRACT FROM AUTHOR]

The simultaneous adsorption of Cu(II) and dyes (MB and MO) on LDH@GO-SH was investigated in single, MB–Cu, and MO–Cu binary systems. The coexistence of dye enhanced the adsorption of Cu(II) by LDH@GO-SH, while the presence of Cu(II) differently affected the adsorption of MB and MO. The adsorption capacity of MO remarkably increased due to the presence of Cu(II). The presence of Cu(II) had a negative effect on MB adsorption for lower MB initial concentration systems (2–10 mg·L−1), while it had a positive effect for higher MB concentration systems (25 mg·L−1 and 50 mg·L−1). The adsorption of Cu(II) in binary systems was satisfactorily fitted by a Langmuir model and pseudo-first-order kinetic model. Surface complex interaction was supposed to be a potential mechanism for the enhancement of Cu(II) adsorption in both MB–Cu and MO–Cu binary systems. The electrostatic interactions between MO and Cu(II) were another reason for the enhancement of Cu(II) adsorption in the MO–Cu binary system. LDH@GO-SH maintained a high adsorption capacity after three adsorption–desorption cycles, indicating that it can be repeatedly used for the treatment of heavy-metal-ion-containing wastewater. [ABSTRACT FROM AUTHOR]

Purpose: Chemical modifications in monoclonal antibodies can change hydrophobicity, charge heterogeneity as well as conformation, which eventually can impact their physical stability. In this study, the effect of the individual charge variants on physical stability and aggregation propensity in two different buffer conditions used during downstream purification was investigated. Methods: The charge variants were separated using semi-preparative cation exchange chromatography and buffer exchanged in the two buffers with pH 6.0 and 3.8. Subsequently each variant was analysed for size heterogeneity using size exclusion chromatography and dynamic light scattering, conformational stability, colloidal stability, and aggregation behaviour under accelerated stability conditions. Results: Size variants in each charge variant were similar in both pH conditions when analyzed without extended storage. However, conformational stability was lower at pH 3.8 than pH 6.0. All charge variants showed similar apparent melting temperature at pH 6.0. In contrast, at pH 3.8 variants A3, A5, B2, B3 and B4 display lower Tm, suggesting reduced conformational stability. Further, A2, A3 and A5 exhibit reduced colloidal stability at pH 3.8. In general, acidic variants are more prone to aggregation than basic variants. Conclusion: Typical industry practice today is to examine in-process intermediate stability with acidic species and basic species taken as a single category each. We suggest that perhaps stability evaluation needs to be performed at specie level as different acidic or basic species have different stability and this knowledge can be used for clever designing of the downstream process to achieve a stable product. [ABSTRACT FROM AUTHOR]

Summary: Proteins are commonly used ingredients to impart certain non‐nutritional properties to foods. Consequently, the industry is constantly seeking to enhance proteins that provide these attributes to food products. Therefore, the aim of this research was to extract the protein from sesame seeds and evaluate the effect of chemical modification through acylation with lauroyl chloride and acetic anhydride on functional properties (solubility index, emulsifying, foaming, swelling and water‐holding and oil‐holding capacity). Chemical modification was successfully demonstrated using FTIR spectroscopy and X‐rays. It was found that acylation with lauroyl chloride or acetic anhydride altered the physicochemical and functional properties, particularly at pH 10. Both reactions exhibited substitution degrees exceeding 20%. Chemical modification via acylation resulted in significant improvements in water and oil retention capacity, emulsifying activity and foaming activity. Thermal analysis revealed significant changes in the modified samples, altering their denaturation temperature, leading to the conclusion that chemical modifications through acylation with lauroyl chloride or acetic anhydride offer benefits in certain functional properties relevant to the food industry. They also represent an opportunity to diversify the application of a by‐product obtained from sesame oil extraction. [ABSTRACT FROM AUTHOR]

The adsorption of copper ions and Reactive Red 120 azo dye (RR-120) as models of water pollutants on unmodified halloysite (H-NM), as well as halloysites modified with sulfuric acid (H-SA) and (3-aminopropyl) triethoxysilane (H-APTES), was investigated. The results showed that adsorption of both the adsorbates was pH-dependent and increased with the increase in halloysite dosage. The adsorption kinetics were evaluated and the results demonstrated that the adsorption followed the pseudo-second-order model. The adsorption isotherms of Cu(II) ions and RR-120 dye on the halloysites were described satisfactorily by the Langmuir model. The maximum adsorption capacities for the Cu(II) ions were 0.169, 0.236, and 0.507 mmol/g, respectively, for H-NM, H-SA, and H-APTES indicating that the NH2-functionalization rather than the surface area of the adsorbents was responsible for the enhanced adsorption. The adsorption capacities for RR-120 dye were found to be 9.64 μmol/g for H-NM, 75.76 μmol/g for H-SA, and 29.33 μmol/g for H-APTES. The results demonstrated that APTES-functionalization and sulfuric acid activation are promising modifications, and both modified halloysites have good application potential for heavy metals as well as for azo dye removal. [ABSTRACT FROM AUTHOR]

Nucleic acid chemistry is a huge research area that has received new impetus due to the recent explosive success of oligonucleotide therapy. In order for an oligonucleotide to become clinically effective, its monomeric parts are subjected to modifications. Although a large number of redesigned natural nucleic acids have been proposed in recent years, the vast majority of them are combinations of simple modifications proposed over the past 50 years. This review is devoted to the main modifications of the sugar phosphate backbone of natural nucleic acids known to date. Here, we propose a systematization of existing knowledge about modifications of nucleic acid monomers and an acceptable classification from the point of view of chemical logic. The visual representation is intended to inspire researchers to create a new type of modification or an original combination of known modifications that will produce unique oligonucleotides with valuable characteristics. [ABSTRACT FROM AUTHOR]

The current research work of Pullulan polysaccharide was reviewed, and the types of physical and chemical modifications of Pullulan polysaccharide were summarized. The chemical modifications were divided into esterification modification, copolymerization crooslinking modification, thiolation modification, etc. The application of its modified products in food processing and food preservation was also reviewed. The future research of Pullulan polysaccharide should focus on the direction of reducing pigment production and hydrophilicity, so as to produce excellent Pullulan polysaccharide based membrane materials. [ABSTRACT FROM AUTHOR]

In this study, the removal of RhB from water by furfural residue (FR) biochar was prepared by hydrothermal carbonization (HTC) and citric acid (CA) modification and named this biochar as CHFR (C refers to citric acid, H refers to hydrothermal carbonization and FR is furfural residue). The CHFR were characterized by SEM, FT-IR and XPS, and CHFR was investigated by the effects of initial concentration, adsorbent dosage, pH, and contact time on the removal of RhB, and the experimental data were analyzed using the adsorption isotherm models, the adsorption kinetic models and thermodynamics, et al. The results showed that CHFR has strong adsorption performance, and the theoretical maximum adsorption capacity of RhB was 39.46 mg·g−1 under the reaction conditions of pH3, the dosage of 1.5 g·L−1, and 120 min contact time, with a removal efficiency close to 100%. the adsorption of RhB by CHFR is spontaneous and endothermic, which is consistent with the Freundlich adsorption, and the isotherm model fits well with the pseudo-second-order model, and the adsorption rate could still be as high as 92.74% after five regenerations, therefore, CHFR is an environmentally friendly and efficient adsorbent with excellent adsorption regeneration performance. [ABSTRACT FROM AUTHOR]

This work intends to evaluate the feasibility of improving the adsorption performance of biomass by both hydrothermal carbonization (HTC) pretreatment and single-step NaOH and ethanol modification. Peanut shell (PS) and pine (PE) are utilized as parent materials to produce efficient adsorbents, and malachite green (MG) is regarded as contaminants to evaluate the adsorption capacity of prepared materials. Adsorption test was performed under various operating conditions, including pH, interfering ions and contact time. The adsorbents were characterized by N2 adsorption–desorption, SEM, FT-IR spectra and elemental analysis to explore the potential adsorption mechanism. Results show that single-step NaOH and ethanol modification is an effective chemical modification to improve the adsorption performance of adsorbents by increasing the surface hydroxyl functional groups. The adsorption performance of adsorbents prepared by HTC following with chemical modification is best; the qe of modified hydrochar from PS and PE (MPS-HC and MPE-HC) reach as high as 570.34 mg/g and 562.2 mg/g, respectively. According to adsorption isothermal and kinetics analysis, the adsorption process mainly occurs on the surface of adsorbents, and MG removal is dominant by chemical adsorption resulting from the increase of surface hydroxyl functional groups by chemical modification. HTC pretreatment could enhance the п–п bond interaction, thus further promoting MG removal by MPS-HC and MPE-HC because it increases the aromaticity of hydrochar evidenced by the H/C ratio decrease. This work indicates that the combination of HTC pretreatment and chemical modification is a feasible way to improve the adsorption performance of biomass. [ABSTRACT FROM AUTHOR]

With the continuous advancement of industrial technology, higher demands have been placed on the properties of gear oils, such as oxidation stability and shear resistance. Herein, the oxidation stability of high-viscosity metallocene poly- α -olefins (mPAOs) was improved by chemical modification via aromatic amine alkylation. The modified mPAO base oils were synthesized separately with diphenylamine (mPAO-DPA) and N-phenyl- α -naphthylamine (mPAO-NPA), and their applicability in industrial gear oil formulations was evaluated. The composition and physicochemical properties of the obtained samples were assessed using 1H NMR spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, and the American Society for Testing and Materials standards (ASTM D445, ASTM D2270, ASTM D92, etc.) confirming the successful completion of the alkylation reaction. The oxidation stability of the samples was also evaluated using pressurized differential scanning calorimetry. The initial oxidation temperature of mPAO-NPA (230 °C) was 53 °C higher than that of mPAO, and the oxidation induction period of mPAO-DPA was nearly twice that of mPAO-NPA. Thermogravimetric analysis in air revealed the increased thermal decomposition temperature and improved thermal stability of modified mPAO. ISO VG 320 industrial gear oils were formulated using mPAO alkylated with N-phenyl- α -naphthylamine(Lub-2) and commercially purchased PAO100 (Lub-1) as base oil components. The antioxidant performance of two industrial gear oils was evaluated through oven oxidation and rotating oxygen bomb tests. The oxidation induction period of Lub-2 was 30% higher than that of Lub-1, with the latter having a lower acid number and a smaller increase in viscosity at 40 °C. Finally, the friction performance of the samples was assessed on a four-ball friction tester, revealing the synergistic effect of the mPAO-NPA base oil with the HiTEC 3339 additive, forming a more stable oil film with a smaller wear scar diameter. [ABSTRACT FROM AUTHOR]

BACKGROUND: Several studies have addressed the adsorption of pesticides such as alachlor, acetochlor, metolachlor and fenthion from water and wastewater, yet the interaction of these compounds with natural organic matter (NOM) complicates their effective removal owing to competitive adsorption effects. This study aims to fill this gap by exploring the efficacy of nitric acid and chlorosulfonic acid‐modified activated carbons (ACs) in removing both pesticides and NOM under realistic environmental conditions. RESULTS: Modifications using nitric acid and chlorosulfonic acid significantly improved the pesticide removal capabilities of Norit SX F Cat (AC1) adsorbents. While both the original and chlorosulfonic acid‐modified adsorbents showed comparable efficacy in pesticide removal, nitric acid‐modified AC Puriss (AC2) adsorbents were less effective. Remarkably, a 100 mg L−1 dose of both original and modified powdered ACs (PACs) removed >98% of all four pesticides from water samples. Additionally, a lower 25 mg L−1 dose effectively achieved similar removal rates, demonstrating their utility as feasible options for water treatment. CONCLUSION: Modifying PACs with nitric acid and chlorosulfonic acid has been proven to enhance their structural and adsorptive properties significantly. These modifications led to improved pesticide removal efficiencies, particularly with the chlorosulfonic acid‐modified PACs, which demonstrated superior performance in adsorption tests. The study also highlighted the competitive adsorption posed by low‐molecular‐weight organic substances in water, which compete with pesticides for active adsorption sites. © 2024 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

In order to explore the effect of chemical modification on the inhibitory effect of intracellular polysaccharides of Phaeodactylum tricornutum (PTP) on the proliferation of cervical cancer Hela cells, in this study, the PTP was extracted by the ultrasound-assisted wall-breaking method combined with the hot water extraction method. Four types of chemical modification (sulfation modification, phosphorylation modification, acetylation modification and carboxymethylation modification ) were carried out on the PTP. The inhibitory effects of the initial PTP, sulfated polysaccharide (S-PTP), phosphorylated polysaccharide (P-PTP), acetylated polysaccharide (A-PTP) and carboxymethylated polysaccharide (C-PTP) on the proliferation of cervical cancer Hela cells were studied. The results showed that the degree of substitution of the S-PTP was 0.714, and the inhibitory effect of S-PTP on the proliferation rate of Hela cells could be up to 9.22% higher than that of PTP. The degree of substitution of P-PTP was 0.191, and the inhibitory effect of P-PTP on the proliferation rate of Hela cells could be up to 4.01% higher than that of PTP. The degree of substitution of acetylated polysaccharide A-PTP was 0.513, and the inhibitory effect of P-PTP on the proliferation rate of Hela cells could be up to 13.53% higher than that of PTP. The degree of substitution of C-PTP was 0.915, and the inhibitory effect of C-PTP on the proliferation rate of Hela cells could be up to 8.39% higher than that of PTP. The results showed that the inhibitory effects of four modified polysaccharides on the proliferation of Hela cells were all greater than that of PTP. Acetylation modification had the greatest inhibitory effect on the proliferation of Hela cells. Compared with PTP, the inhibitory effect of A-PTP against the proliferation rate of cervical cancer Hela cells was increased by 13.53%, reaching 46.05%. Through the experiments of chemical modification of PTP, it was proven that the introduction of a new chemical group into the molecular structure of PTP can lead to a great influence on the inhibition of cervical cancer cell proliferation. This result provides an important reference for further study on the biological activity of Phaeodactylum tricornutum and an experimental basis for subsequent drug research and development. [ABSTRACT FROM AUTHOR]

This paper reviewed the research progress in high-temperature-resistant modification of polycarbonate at home and abroad in recent years from two aspects: chemical and physical modifications. [ABSTRACT FROM AUTHOR]

Chitin is one of the most abundant biopolymers after cellulose, which is present in the cell wall of fungi, the cuticle of insects, and in the exoskeleton of crustaceans such as crabs and shrimps. From the deacetylation of chitin, chitosan is obtained, whose characteristics strongly depend on the degree of deacetylation and its molecular weight. In fact, it can be said that chitosan is the most abundant amino polysaccharide in nature, which is also known as a non-toxic compound. Chitosan has received much attention due to its unique properties such as biocompatibility, biodegradability, antibacterial activity, etc. But due to its low solubility in physiological pH, it is not possible to benefit from many of its properties. Therefore, many attempts have been made to produce its derivatives that have the ability to dissolve in such a condition. One of the most important methods of increasing the solubility of chitosan is its chemical modification, which is done with the so-called quaternization technique. In this method, a modifying agent by establishing a covalent bond with carbon number two of chitosan (C2) increases its solubility in water and at physiological pH. In this article, while re-introducing the unique features of chitosan, various methods of preparing quaternized chitosan using some common chemical compounds such as GTMAC, EPTMAC, CH3I, DMS will be investigated and the characteristics and applications of the produced quaternized chitosan will be described. [ABSTRACT FROM AUTHOR]

N -Methylisothiazolinone (MIT) is a thiol group modifier and antimicrobial agent. Arthrobacter sarcosine oxidase (SoxA), a diagnostic enzyme for assaying creatinine, loses its activity upon the addition of MIT, and its inactivation mechanism remains unclear. In this study, SoxA was chemically modified using MIT (mo-SoxA), and its structural and chemical properties were characterized. Spectral analysis data, oxygen consumption rates, and reactions were compared between intact SoxA and mo-SoxA. These demonstrate that the oxidative half-reaction toward oxygen is inhibited by MIT modification. The oxidase activity of mo-SoxA was approximately 2.1% of that of intact SoxA, and its dehydrogenase activity was approximately 4.2 times higher. The C-to-S mutants revealed that cooperative modification of 2 specific cysteine residues caused a drastic change in the enzyme reaction mode. Based on the modeled tertiary structures, the putative entrance for oxygen uptake is predicted to be blocked by the chemical modification of the 2 cysteine residues. [ABSTRACT FROM AUTHOR]

Standard glass fiber filter media were chemically modified with suitably chosen surface-active agents. The aim of these modifications was to improve the three fundamental filtration performance characteristics, namely, to increase the separation efficiency, reduce the differential pressure (∆P) and increase the dirt holding capacity (DHC). The increase in separation efficiency was considered quantitatively in terms of changes in the work of adhesion between the contaminant and the modified media substrate derived from the contact angle measurements. The experimental confirmation of this behavior was demonstrated by an improved separation efficiency especially for particles in the smaller size ranges, well below the mean porosity of the original substrate. In addition, the effect of different surface modifications, especially those of the opposite ends of the surface energy values, has clearly manifested itself in the experimental results of separation efficiency derived from the multipass evaluations. Collectively, the obtained contact angle (surface energy) and separation efficiency results are strongly indicative of a wide range of filtration performance enhancements that can be achieved through suitably chosen surface-active modification of standard substrate materials. [ABSTRACT FROM AUTHOR]

Facing increasing social, environmental, and economic pressure to substitute non-renewable fossil resources with renewable ones, hemicellulose has received attention as a substrate for the production of high-value products such as packaging materials because of its non-toxicity, abundance, and biodegradability. Hemicelluloses in the cell wall are naturally substituted with acetyl groups, and the degree and pattern of acetylation vary among plant species, tissue and cell types, and plant maturity. Hemicellulose acetylation influences features such as the flexural properties of wood, polysaccharide interactions, plant growth, and stress resistance. However, hemicellulose is deacetylated during its separation from other biomass polymers, mainly via alkaline solubilization. Therefore, when industrial applications require a certain degree of acetylation, chemical acetylation is necessary, which occurs through an esterification reaction that links acetyl groups to hemicellulose, catalyzed or not. Acetylation may enhance some features of hemicellulose-based packaging materials, such as mechanical strength, processability, thermal stability, hydrophobicity, and oxygen and water vapor permeability. This review provides an update on the latest advances in plant polysaccharide acetylation, including the acetylation mechanism in the plant cell wall as well as the influence of such esterification on plant properties and wood industrial application. Recent developments and progress in hemicellulose chemical acetylation strategies have been summarized, disclosing the advantages and disadvantages of different solvents and catalysts applied and acetylation evaluation methods. [ABSTRACT FROM AUTHOR]

The fibers from four wheat varieties (FT, XW 26, XW 45, and KW 1701) were selected and chemically modified with NaOH, epichlorohydrin, and dimethylamine to improve the adsorption capacity for anionic dye. The structure of the fibers with or without modification was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectrometry. The modified products were studied from the aspects of adsorption capacities, adsorption kinetics, and thermodynamics to provide a reference for the utilization of wheat bran. By SEM, more porous and irregular structures were found on the modified fibers. The XRD results showed that the crystals from the original fibers were destroyed in the modification process. The changes in fibers' infrared spectra before and after modification suggested that quaternary ammonium salts were probably formed in the modification process. The maximum adsorption capacity of wheat bran fibers for Congo red within 120 min was 20 mg/g for the unmodified fiber (XW 26) and 93.46 mg/g for the modified one (XW 45). The adsorption kinetics of Congo red by modified wheat bran fiber was in accord with the pseudo-second-order kinetic model at 40 °C, 50 °C, and 60 °C, indicating that the adsorption process might be mainly dominated by chemisorption. The adsorption was more consistent with the Langmuir isothermal adsorption model, implying that this process was monolayer adsorption. The thermodynamic parameters suggested that the adsorption occurred spontaneously, and the temperature increase was favorable to the adsorption. As mentioned above, this study proved that the wheat bran fiber could possess good adsorption capacities for anion dye after chemical modification. [ABSTRACT FROM AUTHOR]

The aim of the present study was to compare the effectiveness of raw chicken feathers (RCFs), NaOH and ethylenediamine-modified chicken feathers (MCFs), and xanthate-modified chicken feathers (XMCFs), treated with both NaOH, ethylenediamine, and carbon disulfide. The physicochemical characteristics of the biosorbents were analyzed using attenuated total reflection Fourier transform infrared spectrophotometry (ATR-FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), adsorption of N2 at −196°C and point of zero charge determination (pHpzc). The biosorption of Cr(VI) using MCFs and XMCFs was evaluated through various parameters, namely, pH, biosorbent amount, and contact time in batch experiments. The results showed a significant increase in the biosorption capacities of MCFs (90.90 mg/g) and XMCFs (100 mg/g) compared to RCFs (52.63 mg/g). The batch adsorption experiments indicated that the optimal conditions for biosorption were pH 2.0, with an equilibrium contact time of 90 min for RCFs, and 60 min for both MCFs and XMCFs. The optimal biosorbent concentrations were 16 g L−1 for RCFs and 12 g L−1 for both MCFs and XMCFs. The biosorption behavior was well described by the Langmuir isotherm and pseudo-second-order kinetic models. The thermodynamic parameters indicated that the biosorption of Cr(VI) onto the biosorbents was a spontaneous and endothermic process. Desorption analysis was carried out using a 0.1 M NaOH solution. [ABSTRACT FROM AUTHOR]

In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth, base, and silanized with GPTMOS (3-glycidoxypropyltrimethoxysilane), OTES (n-octyltriethoxysilane), and MTMOS (methyltrimethoxysilane) silanes. The addition of two types of waxes, synthetic polyamide wax and natural beeswax, were used as a factor to increase the rheological properties of the composites. The obtained samples were characterized in terms of the effect of filler silanization on the degradation rate of the composites. The tests were conducted under different conditioning conditions, i.e., after exposure to strong UV radiation for 250 and 500 h, and under natural sunlight for 21 days. The conditioning carried out under natural conditions showed that the modified samples exhibit up to twice the degradation rate of pure polylactide. The addition of synthetic wax to the composites increases the tendency to agglomerate diatomaceous earth, while natural wax has a positive effect on filler dispersion. For composites modified with GPTMOS and OTES silanes, it was noted that the addition of natural wax inhibited the degree of surface degradation, compared to the addition of synthetic wax, while the addition of MTMOS silane caused the opposite effect and samples with natural wax degraded more strongly. It was shown that, despite the high degree of surface degradation, the process does not occur significantly deep into the composite and stops at a certain depth. [ABSTRACT FROM AUTHOR]

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