Availability Of Functional Groups Research Articles

POPs to COFs by post-modification: CO2 chemisorption and dissolution.

Porous organic polymers (POPs) and covalent organic frameworks (COFs) are hierarchical nano materials with variable applications. To our knowledge, this is the first report of a post-modified, non-renewable, DMSO-soluble M-POP/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) upon atmospheric H2O/CO2 trapping after 48 h, forming a DBUH+·HCO3- adduct, as verified by solution carbon-13 nuclear magnetic resonance (13C NMR) spectroscopy. The success of the post-modification resulting from aldehyde enriched POPs was proven spectroscopically. The accessible functional group was reacted with excess monoethanolamine (MEA) resulting in the formation of M-POP. Away from CO2 physisorption, only few examples have been reported on the chemisorption process. One such example is the ethylene diamine-functionalized E-COF, capable of capturing CO2via carbamation. This was evidenced by several qualitative measurements including colorimetry and conductivity, which showed an unprecedented water solubility for a 2D COF material. The crystallinity of COFs as a result of post-modification was proven by powder X-ray diffraction (PXRD).

Silica nanoparticle conjugation with gallic acid towards enhanced free radical scavenging capacity and activity on osteosarcoma cells in vitro.

Gallic acid (GA), derived from land plants, possesses diverse physiological benefits, including anti-inflammatory and anticancer effects, making it valuable for biomedical applications. In this study, GA was used to modify the surface of dendritic mesoporous silica nanoparticles (DMSNs) via carbamate (DMSN-NCO-GA) or amide (DMSN-NH-GA) bonds, using a post-grafting technique. To explore GA-conjugated materials' potential in modulating cancer cell redox status, three variants of osteosarcoma cells (U2-OS) were used. These variants comprised the wild-type cells (NEO), the cells overexpressing the wild-type human Golgi anti-apoptotic protein (hGAAP), and the null mutant of hGAAP (Ct-mut), as this protein was previously demonstrated to play a role in intracellular reactive oxygen species (ROS) accumulation and cell migration. In the absence of external ROS triggers, non-modified DMSNs increased intracellular ROS in Ct-mut and NEO cells, while GA-conjugated materials, particularly DMSN-NH-GA, significantly reduced ROS levels, especially pronounced with higher GA concentrations and notably in hGAAP cells with inherently higher ROS levels. Additionaly, NH-GA conjugates were less cytotoxic, more effective in reducing cell migration, and had higher ROS buffering capacity compared to DMSN-NCO-GA materials. However, in the presence of the external stressor tert-butyl-hydroperoxide (TBHP), NCO-GA conjugates showed more efficient reduction of intracellular ROS. These findings suggest that varying chemical decoration strategies of nanomaterials, along with the accessibility of functional groups to the cellular environment, significantly influence the biological response in osteosarcoma cells. Highlighting this, GA-conjugation is a promising method for implementing antioxidant properties and inhibiting cancer cell migration, warranting further research in anticancer treatment and drug development.

Theoretical Study of Microgel Functional Groups' Mobility.

Polymer microgels, micrometer-sized cross-linked polymer particles, are considered to be a promising type of advanced materials for a wide range of applications. To enhance the microgels' applicability, it is essential to incorporate various functional groups into a microparticle polymer network. Yet, the availability of functional groups for the interaction with surroundings depends strongly on the properties of the polymer network and has a great impact on further effective usage. In this theoretical study, we address this question and, with the help of coarse-grained molecular dynamics computer simulations, assess the segmental mobility and accessibility of functional groups bound to polymer network depending on microgel architecture and solvent quality. Additionally, we evaluate the minimum number of functional groups needed to facilitate the hopping mechanism between the functional groups (i.e., charge transfer). As an example of practical implementation of the obtained results, we estimate the optimal network topology for redox-active microgels to provide the maximum charge capacity for the dispersion electrolyte in redox-flow batteries.

Radiation synthesized carboxyl-functionalized covalent organic framework adsorbent for efficient heavy metal decontamination

Carboxyl groups exhibit great potential in the field of heavy metal decontamination due to their good coordination ability. In this work, acrylic acid was grafted onto covalent organic framework (COF) by using a γ-ray radiation grafting approach. A carboxyl-functionalized adsorbent designated AA-TbDa-COF with high performance for multiple heavy metal removal was obtained. Infrared spectroscopy and thermogravimetric analysis proved the successful carboxyl modification. The porous nanofiber morphology and high accessibility of carboxyl functional groups give the resultant AA-TbDa-COF ultra-fast adsorption kinetics. The capacity for Pb2+, Cd2+ and Cu2+ decontamination was 127.9, 60.6 and 39.8 mg/g, respectively. The preparation of functional COFs by radiation method is extended to the field of heavy metal treatment, proving the great potential of radiation-prepared materials in environmental governance.

Recent Advances in the Polish Research on Polysaccharide-Based Nanoparticles in the Context of Various Administration Routes.

Polysaccharides are the most abundant polymers in nature. They exhibit robust biocompatibility, reliable non-toxicity, and biodegradable character; thus, they are employed in multiple biomedical applications. The presence of chemically accessible functional groups on the backbone of biopolymers (amine, carboxyl, hydroxyl, etc.) makes them suitable materials for chemical modification or drug immobilisation. Among different drug delivery systems (DDSs), nanoparticles have been of great interest in scientific research in the last decades. In the following review, we want to address the issue of rational design of nanoparticle (NP)-based drug delivery systems in reference to the specificity of the medication administration route and resulting requirements. In the following sections, readers can find a comprehensive analysis of the articles published by authors with Polish affiliations in the last few years (2016-2023). The article emphasises NP administration routes and synthetic approaches, followed by in vitro and in vivo attempts toward pharmacokinetic (PK) studies. The 'Future Prospects' section was constructed to address the critical observations and gaps found in the screened studies, as well as to indicate good practices for polysaccharide-based nanoparticle preclinical evaluation.

Targeted antibacterial potency against multidrug resistance pathogen enhanced with N, S co-doped carbon quantum dots selectively recognizes rifampicin

A simple environment-friendly nitrogen, sulphur dual doped carbon quantum dots (N, S-CQDs) has been developed via a simple microwave-assisted method using mercaptosuccinic acid and diethylenetriamine. The interactions of the N, S-CQDs with various randomly chosen common commercial antibiotics were studied using their indigenous fluorescence properties. The N, S-CQDs were found to selectively interact with rifampicin over other tested antibiotics via the interaction between the accessible functional groups of N, S-CQDs and rifampicin resulting in loss of its fluorescence. The interaction of N, S-CQDs and rifampicin was tight and irreversible. Thus, the environmental exposure of free rifampicin, rifampicin-directed antimicrobial resistance among bacteria, and rifampicin toxicity might be mitigated in the future by the use of these N, S-CQDs. While tested on the HuH-7 human cell line, we found that the N, S-CQDs neither can kill nor impair the proliferation of the cells, indicating its non-cytotoxic nature. Furthermore, the quantum dot also possesses antimicrobial activity against both Gram-positive, and Gram-negative bacteria and their drug resistance varieties possibly by disrupting the cellular boundaries. N, S-CQDs could be effective next-generation antimicrobials for having synergistic nature when applied with other common antibiotics.

Insights into mass transfer mechanism and micro-interaction of melanoidin adsorption on polyethyleneimine-functionalised pomelo-peel-derived aerogel

Melanoidins are recalcitrant colouring and polluting polymers present in the effluent streams of molasses-based distilleries. Adsorption is the most prospective technology with ease of operation and high efficiency. Herein, the removal of melanoidins from spent wash was investigated by synthesising a polyethyleneimine (PEI) functionalised pomelo-peel (PP) derived aerogel (PEI-PPA). The PEI-PPA is distinguished by the porous network structure and abundant accessible functional groups (mainly protonated primary amine) that are conducive to the elimination of colouring contaminants (melanoidins). The incorporation of PEI into supporting matrices (i.e., PP–derived aerogel) effectively improved the melanoidin adsorption capacity (from a previous-best research of 230 mg/g to the current 615.70 mg/g), while the melanoidin removal rate reached 92.36 %. The independent gradient model and Hirshfeld surface analysis were used to investigated the possible electroweak interaction relationship between PEI-PPA and melanoidin. By analysing the number of melanoidin molecules bonded to each active site using a novel double-layer adsorption model, a mixed inclination (parallel and non-parallel orientation) of melanoidin onto the PEI-PPA surface was found. For the two mass transfer models fitted results, the adsorption onto the active sites (AOAS) model better described the behaviour of melanoidin adsorption by PEI-PPA than the external diffusion resistance–internal diffusion resistance (EDR–IDR) mixed model under the same conditions, revealing the AOAS was rate-controlling during the mass transfer process. AOAS both contained chemisorption and physisorption. The calculated rates of chemisorption were far higher than those of physisorption before equilibration, indicating chemisorption was main the rate-determining step. Altogether, this work proposed an effective conversion for PP into bio-adsorbent and provided a detailed analysis of mass transfer mechanism.

Evaluation of a ZnCl2-modified biochar derived from activated sludge biomass for adsorption of sulfamethoxazole

Sulfamethoxazole (SMX) was effectively removed from aqueous solution via adsorption to a chemically modified biochar created using a simple and rapid microwave (MW) pyrolysis of activated municipal wastewater sludge. Response surface methodology (RSM) was used to maximize SMX adsorption capacity optimizing three independent synthesis parameters including ZnCl2 concentration (0.5–1.5 mol/L), MW time (3–10 min), and MW power (400–1000 W). ZnCl2 modified biochar (ZnBC) synthesized under the optimized conditions (ZnCl2 concentration = 1.5 mol/L, MW time = 8 min, and MW power = 915 W) was analyzed by different characterization techniques including Brunauer Emmett and Teller (BET) surface area analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS), and point of zero charge (pHpzc). ZnCl2 impregnation coupled with a homogenous MW heating profile led to improved accessibility of surface functional groups with a specific surface area of 214 m2/g and robust porous structure with an average pore volume of 0.127 cm3/g. Adsorption experiments using the optimized ZnBC resulted in a 89% SMX removal efficiency and maximum SMX adsorption capacity of 50.6 mg/g. Isotherm and kinetic analysis suggested multilayer chemical adsorption of SMX over a heterogeneous biochar surface followed by heterogenous pore diffusion into the ZnBC pores. Results showed that acidic pH favors SMX removal through a spontaneous and exothermic process. The application of modified activated sludge-based biochar introduces a new sustainable method for treating pharmaceuticals and recycling waste sludges from wastewater treatment plants.

Mechanistic Influence of Polymer Species, Molecular Weight, and Functionalization on Mucin–Polymer Binding Interactions

Improving both systemic and localized delivery of pharmaceuticals by optimizing the delivery vehicle properties is a major area of ongoing research. One such engineered property is mucoadhesion, wherein polymers are tailored to optimize polymer–mucin interactions to increase drug residence times and uptake efficiency. There are many examples of mucoadhesion as a drug delivery modality in the literature, yet the underlying mechanisms remain poorly understood, and its clinical translation is limited. Within this mechanistic lens, we found that nuclear magnetic resonance (NMR) is a powerful tool for uncovering polymer–mucin interactions. We investigated the influence of several polymer design parameters including molecular weight and repeating unit functionalization on mucoadhesion and uncovered several key findings in terms of the influence of these design parameters on polymer–protein intermacromolecular interactions. First, we probed individual polymer species including hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and carboxymethyl cellulose (CMC) and identified that molecular-weight-driven changes in the polymer–mucin interaction fingerprint result from perturbations in the polymer-specific binding complex. Specifically, we found that CMC and HPC complexes spatially reorient with increasing molecular weight, whereas HPMC complexes do not. We expanded this comparison to include functional group changes to the polymer repeating unit, where we showed that the addition of methyl groups to cellulose derivatives induces a unique binding fingerprint. Next, we expanded the mucoadhesive polymer series to include CMC, HPC, HPMC, poly(acrylic acid) (PAA), and poly((2-dimethylamino)ethyl methacrylate) (PDMAEMA) and observed a negative correlation between molecular weight and mucoadhesive interaction intimacy, highlighting the differences across polymer species. Finally, we explored polymers that lack mucin interactions to illustrate the limitations of polymer composition and molecular weight as predictors of mucoadhesive fate. Altogether, these experiments were used to report on mucoadhesive interactions at the atomic level and revealed that polymer design is dependent on both the availability and accessibility of mucoadhesive functional groups.

Electrospun Polylactic Acid-Based Fibers Loaded with Multifunctional Antibacterial Biobased Polymers.

Here, we report the development of antibacterial and compostable electrospun polylactic acid (PLA) fibers by incorporation of a multifunctional biobased polymer in the process. The multifunctional polymer was synthesized from the bio-sourced itaconic acid building block by radical polymerization followed by click chemistry reaction with hydantoin groups. The resulting polymer possesses triazole and hydantoin groups available for further N-alkylation and chlorination reaction, which provide antibacterial activity. This polymer was added to the electrospinning PLA solution at 10 wt %, and fiber mats were successfully prepared. The obtained fibers were surface-modified through the accessible functional groups, leading to the corresponding cationic triazolium and N-halamine groups. The fibers with both antibacterial functionalities demonstrated high antibacterial activity against Gram-positive and Gram-negative bacteria. While the fibers with cationic surface groups are only effective against Gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus aureus), upon chlorination, the activity against Gram-negative Escherichia coli and Pseudomonas aeruginosa is significantly improved. In addition, the compostability of the electrospun fibers was tested under industrial composting conditions, showing that the incorporation of the antibacterial polymer does not impede the disintegrability of the material. Overall, this study demonstrates the feasibility of this biobased multifunctional polymer as an antibacterial agent for biodegradable polymeric materials with potential application in medical uses.

Controlled synthesis of graphene oxide/silica hybrid nanocomposites for removal of aromatic pollutants in water

The remarkable characteristics of graphene make it a model candidate for boosting the effectiveness of nano-adsorbents with high potential owing to its large surface area, π–π interaction, and accessible functional groups that interact with an adsorbate. However, the stacking of graphene reduces its influence adsorption characteristics and also its practical application. On the other hand, the widespread use of aromatic compounds in the industry has aggravated the contamination of the water environment, and how to effectively remove them has become a research hotspot. Herein, we develop the functionalization of silica nanoparticles on graphene oxide nanosheet (FGS) by a facile, cheap, and efficient synthesis protocol for adsorption of Trypan Blue (TB) and Bisphenol A (BPA). It was demonstrated that chemical activation with KOH at high autoclaving temperature successfully transformed rice husk ash (RHA) into FGS. The graphene oxide layered interlamination was kept open by using SiO2 to expose the interlayers' strong adsorption sites. XRD, EDX, FTIR, Raman spectroscopy, SEM, HR-TEM, and BET surface area are used to investigate the chemical composition, structure, morphology, and textural nature of the as-produced FGS hybrid nanocomposite. The various oxygen-containing functional groups of the hybrid nanocomposites resulted in a significantly increased adsorption capacity, according to experimental findings. In addition, FGS2, the best composite, has a specific surface area of 1768 m2g−1. Based on Langmuir isotherms, the maximal TB dye and BPA removal capacity attained after 30 min were 455 and 500 mg/g, respectively. The Langmuir isotherm model, a pseudo-second-order kinetic model, and an intraparticle diffusion model have all been used to provide mechanistic insights into the adsorption process. This suggests that BPA and TB adsorption on FGS2 is mostly chemically regulated monolayer adsorption. Due to its unique sp2-hybridized single-atom-layer structure, the exposed graphene oxide nanosheets' extremely hydrophobic effect, hydrogen bonding, and strong—electron donor–acceptor interaction contributed to their improved adsorption of BPA and TB. According to adsorption thermodynamics, FGS2 adsorption of TB and BPA is a spontaneous exothermic reaction that is aided by lowering the temperature. For adsorption-based wastewater cleanup, the produced nanocomposites with a regulated amount of carbon and silica in the form of graphene oxide and silica can be used. These findings suggest that functionalized GO/SiO2 hybrid nanocomposites could be a viable sorbent for the efficient and cost-effective removal of aromatic chemicals from wastewater.

Recovery of 17β-Estradiol Using 3D Printed Polyamide-12 Scavengers.

Over the past decades, endocrine-disrupting compounds have been under active studies due to their potential environmental impact and increased usage. The actual hormones, especially estrogens, have shown to be one of the major contributors to hormonal waste in wastewater. Wastewater treatment facilities have variable capabilities to handle hormonal compounds and, therefore, different quantities of harmful compounds may end up in the environment. We introduce a simple technique to remove estrogens, such as 17β-estradiol (E2) from wastewater by using 3D printed polyamide-12 (PA12) filters. A selective laser sintering 3D printing was used to manufacture porous PA12 filters with accessible functional groups. Adsorption and desorption properties were studied using gas chromatography with flame ionization detector. The results showed that near quantitative removal of E2 was achieved. The 3D printed filters could also be regenerated and reused without losing their efficiency. During regeneration, E2 could be extracted from the filter without destroying the compound. This opens up possibilities to use the hormone scavenger filters also as concentration tools enabling accurate analyses of sources with trace concentrations of E2.

Graphene oxide modified tilted fiber Bragg grating for 10<sup>–12</sup> level heavy metal ion sensing

Graphene oxide (GO) is an ideal label-free sensing material with its super large specific surface area and abundant surface functional groups. Considering its insulating characteristic, the GO is suitable for optics-based heavy metal ion sensing. However, given the large surface tension of water and the hydrophilicity of GO, the agglomeration or wrinkles of GO nanosheets is usually inevitable during coating with aqueous dispersion. This reduces the accessible surface area and surface functional groups of GO, thereby degrading the sensing performance. Here, an ultra-sensitive GO functionalized tilted fiber Bragg grating (TFBG) sensor is designed to detect heavy metal ions in aqueous solutions. Firstly, a strategy of free energy manipulation is employed to avoid the wrinkles and agglomeration of GO nanosheets. In the scenario of aqueous dispersion, the GO nanosheets will wrinkle as the water droplets evaporate and shrink. In contrast, using the lower-surface-tension ethanol as the dispersant and a high-surface-energy substrate processed by oxygen plasma, the dispersion will evenly spread on the substrate instead of forming droplets. When ethanol evaporates, GO nanosheets are attached to the substrate in largest possible area to reduce the free energy of the system, by which a GO film without agglomeration or wrinkles can be obtained. Secondly, the intrinsic sensitivity of TFBG is conducive to the detection of heavy metal ions in water. Mode interference occurs between the cladding mode and the core mode in the TFBG, and the wavelength and intensity of the interference are highly sensitive to the surrounding temperature, stress, and refractive index. Combining the above characteristics, the GO functionalized TFBG is highly sensitive to Pb<sup>2+</sup>, Cd<sup>2+</sup>, and Cu<sup>2+</sup> ions in water. These heavy metal ions are adsorbed by the GO, and thus causing the effective refractive index to increase. The results show that the adsorption of heavy metal ions makes the interference peaks red-shifted in the transmission spectrum. The lowest detection limit for Pb<sup>2+</sup> and Cd<sup>2+</sup> can reach 10<sup>–10</sup> mol/L (ng/L level), and the corresponding sensitivities are 0.426 and 0.385 dB/(nmol·L<sup>–1</sup>) (2.06 and 3.43 dB/(μg·L<sup>–1</sup>)), respectively. These superior sensing performances benefit from the high specific surface area and accessible carbonyl groups of the unfolded GO, and also rely on the excellent intrinsic sensitivity of TFBG. The GO functionalized TFBG sensor has a promising potential application in environment monitoring.

Synthesis of an Ethylenediamine-Modified Hypercrosslinked Polymer and its Preliminary Study for Antipyrine and Pamabrom Extraction

Emerging contaminants (EC) are naturally occurring or synthetic chemicals that may enter the environment and cause adverse effects to aquatic and human health. EC consist of pharmaceuticals, pesticides, organic chemicals and personal care products that present in water sources at low concentrations (μg/L), hence, they are not widely monitored in the environment. Pharmaceuticals contain biologically-active components that pollute water courses. These generally originate from human waste or the uncontrolled release of residues from chemical plants. The removal of pharmaceutical compounds from water can be carried out using polymeric materials with high specific surface areas and good selectivity due to the presence of accessible active functional groups. In the present work, the synthesis and characterizations of microspheres, acrylonitrile-co-divinylbenzene-80-co-vinylbenzylchloride(AN-co-DVB-80-co-VBC) terpolymers with weak-anion-exchange (WAX) character and high porosity have been successfully carried out. The polymeric microspheres were synthesized by precipitation polymerization and subsequently hypercrosslinked (HXL) via a Friedel-Crafts reaction. The HXL terpolymer was then chemically modified with 1,2-ethylenediamine (EDA) to incorporate diamine functional groups, which improved the selectivity of the HXL microspheres towards polar compounds. Fourier Transform-Infrared (FT-IR) spectra of the EDA-modified HXL terpolymer showed that the nitrile groups derived from AN units were utilized due to the presence of diamine groups along the polymeric chains, indicating that the chemical modification was successful. The microanalysis showed that the chlorine content of the polymer was significantly decreased after hypercrosslinking, indicating that the reaction was successful. The nitrogen content increased after chemical modification with EDA, indicating successful chemical modification of the microspheres. The polymers were in the form of spherical monodisperse polymer microspheres with mean particle diameters of ~7.00 μm. The highest observed specific surface areas (SSAs) of the HXL terpolymer and EDA-modified HXL terpolymer were 2,274 m²/g and 503 m²/g, respectively. The microspheres were utilized to extract the pharmaceutical compounds antipyrine and pamabrom from aqueous solution using the dispersive solid phase extraction (DSPE) method. The extraction analysis was carried out by Gas Chromatography–Mass Spectrometry (GC-MS). The influence of adsorbent dosage, extraction time and elution time were studied to evaluate the performance of the adsorbent in the extraction of antipyrine and pamabrom from aqueous solution. It can be concluded that EDA-modified HXL poly(AN-co-DVB-80-co-VBC) was more favourable towards the extraction of antipyrine, which had a maximum extraction efficiency (EE%) of 95%, compared to that of pamabrom (maximum EE% of 54%).

CO2-in-Water Pickering Emulsion-Assisted Polymerization-Induced Self-Assembly of Raspberry-like sorbent microbeads for uranium adsorption

• An amino oxime functionalized raspberry-like sorbent microbeads is firstly prepared for uranium extraction. • A new idea for the controllable interface assembly of nano-sized particles was provided. • RL-SMs exhibited a remarkable uranium removal efficiency when multiple metal ions coexist. • RL-SMs shows a fast adsorption equilibrium, which only need 30 min. Highly efficient adsorption of radioactive uranium from seawater is a grand challenge of mounting severity as the energy demand increases. To address this, a salicylaldoxime functionalized raspberry-like microbeads sorbent is created to achieve highly efficient uranium adsorption via the CO 2 -in-Water Pickering emulsion-assisted polymerization-induced self-assembly method. The prepared raspberry-like microbeads sorbent with a high density of accessible functional groups exhibits the maximum uranium adsorption capacity of 41.02 mg g −1 within 30 min, the time required to reach adsorption equilibrium is shorter than most of the reported amine-oxime functionalized microsphere adsorbents. In addition, under the coexistence of high-concentration metals such as Na + , Mg 2+ , K + , Ca 2+ , etc., the raspberry-like microbeads sorbent still showed the best affinity for uranium, which is mainly benefit from the specific binding between amine oxime group and uranium. Our work not only provides a general strategy for the rapid and selective adsorption of uranium from seawater, but also provides a new perspective for the controlled assembly of NSs and the preparation of nano-hybrid materials combining the advantages of micro/nano structures.

Arbuscular mycorrhizal fungi outcompete fine roots in determining soil multifunctionality and microbial diversity in a desert ecosystem

Fine roots and mycorrhizal fungi play a crucial role in soil nutrient cycling and microbial processes. However, the importance of the symbioses between fine roots and arbuscular mycorrhizal fungi (AMF) in different plant functional groups to maintain soil multifunctionality (the ability to provide multiple functions and services) and microbial diversity remains unclear, especially in desert ecosystems. In this study, we conducted an ingrowth core experiment on three vegetation types, namely shrub-dominated, grass-dominated, and mixed vegetation communities, in the Mu Us Desert, northern China, to investigate the importance of fine roots and mycorrhizal fungi in shaping soil nutrient composition and microbiome. Furthermore, we detected the relationships among AMF-related inputs [extraradical AMF hyphae and glomalin-related soil protein (GRSP)], soil multifunctionality, and soil microbial diversity. We found that most of the soil properties associated with nutrient cycling and microbial community composition and diversity varied among the three vegetation types, but were not significantly different between distinct ingrowth core treatments with fine root and hyphal access. AMF-related inputs, especially the easily extractable GRSP, were the most important determinants of soil multifunctionality and microbial community diversity across the shrub and grass communities, while the changes in soil multifunctionality and microbial diversity were inconsistent with the trend of fine root biomass. Moreover, AMF-related inputs were positively correlated with soil nutrients, particularly soil organic carbon (SOC). In contrast to the minimal negative correlation between SOC and soil microbial richness, soil multifunctionality was positively correlated with SOC. These findings support the role of AMF in shaping soil multifunctionality and microbial diversity by stabilizing SOC in a desert ecosystem, regardless of the fine root accessibility of plant functional groups. Therefore, this study improved our understanding of plant-derived carbon in the soil and its effects on the induction of soil abiotic and biotic processes in resource-limited ecosystems.

Enhancement in hydrolytic stability and proton conductivity of optimised chitosan/sulfonated poly(vinyl alcohol) composite membrane with inorganic fillers

The study aimed to obtain a chitosan/sulfonated poly(vinyl alcohol) (CS/SPVA) membrane with optimised hydrolytic stability and ion conduction properties by using the Taguchi method. Three factor variables including concentration of glutaraldehyde (GA), crosslinking temperature and crosslinking time were considered. An L18 orthogonal array along with the approach of larger-the-better was selected for the optimisation. The highest value in S/N ratio of −19.9947 was observed on sample set 9 without GA involvement, crosslinking temperature of 110°C and time of 90 minutes. The ionic conductivity and water uptake were 8.21 mS/cm and 82.05%, respectively, compared to 7.34 mS/cm and 215.9% of the nonoptimised CS/SPVA15. Further inspection with the incorporation of inorganic fillers (titanium dioxide (TiO2), silicon dioxide (SiO2) and sulfonated graphene oxide (SGO)) was conducted on the optimised CS/SPVA15. The thermomechanical properties of CS/SPVA15 composite membrane was improved with inorganic fillers. In terms of electrochemical properties, ionic conductivity was reduced because of the enhancement in thermal stability. The inorganic filler inhibits the accessible functional groups and increase the ionic resistance of CS/SPVA15 composite membrane. Amongst all samples, CS/SPVA15-SGO is the most optimised with a minor trade-off in ionic conductivity (6.82 mS/cm) and IEC (0.8866 mequiv/g) compared with CS/SPVA15, whilst delivering an exceptional hydrolytic stability (76.41%).

Modification of biochar with high-energy ball milling: Development of porosity and surface acid functional groups

Biochar is widely used in many applications and its properties can be modified with various methods, including ball milling. In this work, six different biochar materials (made from pine, hemp, switchgrass, pulp sludge, wheat straw, and sugarcane bagasse) were ball milled and characterized. The pore volume and surface area measured by N2 adsorption increased after milling, but that measured by CO2 changed minimally suggesting that occluded pores were exposed. Ball milling also increased the total number of accessible carboxylic, phenolic, and lactonic groups on the surface proportionally to the initial oxygen content, but no new functional groups were detected with FTIR. To account for different milling conditions reported in the literature, the total applied energy was correlated to the developed properties. The methylene blue adsorption capacity of the biochar increased after milling up to 256 mg/g (20-fold increase), which was proportional to the increase in accessible oxygen functional groups.

Synthesis of short-range ordered aluminosilicates at ambient conditions

We report here on structure-related aggregation effects of short-range ordered aluminosilicates (SROAS) that have to be considered in the development of synthesis protocols and may be relevant for the properties of SROAS in the environment. We synthesized SROAS of variable composition by neutralizing aqueous aluminium chloride with sodium orthosilicate at ambient temperature and pressure. We determined elemental composition, visualized morphology by microscopic techniques, and resolved mineral structure by solid-state 29Si and 27Al nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Nitrogen sorption revealed substantial surface loss of Al-rich SROAS that resembled proto-imogolite formed in soils and sediments due to aggregation upon freezing. The effect was less pronounced in Si-rich SROAS, indicating a structure-dependent effect on spatial arrangement of mass at the submicron scale. Cryomilling efficiently fractured aggregates but did not change the magnitude of specific surface area. Since accessibility of surface functional groups is a prerequisite for sequestration of substances, elucidating physical and chemical processes of aggregation as a function of composition and crystallinity may improve our understanding of the reactivity of SROAS in the environment.

The comparative analysis of the methods for keratin extraction from sheep wool and human hair

Nowadays, biopolymers such as keratins are widely used in biomedicine due to their low toxicity, biocompatibility, and biodegradability. At the molecular level, keratins differ from other structural proteins by a high content of disulfide bonds, which provide the formation of a compact three-dimensional structure resistant to biological and chemical degradation. Native keratins are highly ordered, whereas, recovered keratins are characterized by a flexible structure with more accessible functional groups. A characteristic feature of solubilized keratins is their ability to polymerize; therefore, they are widely used to create biomaterials. The extraction of keratins from natural fibers is an important step to the development of functional biomaterials. However, this process is complicated by the presence of a large number of intramolecular and intermolecular disulfide bonds in keratins. That is why keratin extraction by breaking the intermolecular disulfide bonds while preserving the covalent bonds of the polypeptide chain is necessary. The goal of our study was to estimate the different methods of solubilized keratin obtaining. In the experiments, samples of different types of wool and human hair were used. Various methods of keratin extraction were applied. The yield of solubilized keratin (%) was calculated from the ratio of the weight of the lyophilized keratin extract and the initial weight of fibers. The molecular mass of recovered keratins was evaluated by SDS-PAAG electrophoresis in the Laemmli buffer system. An analysis of the efficiency of keratin extraction has shown that solubilized keratin yield ranged from 32% to 51% and depended on the composition of the extraction mixture. Electrophoretic analysis of all keratin extracts obtained by various methods confirmed the presence of two bands, which according to the molecular weight corresponding to I and II types of proteins of intermediate filaments. The presence of these proteins provides self-assembly into complex structures.