Water Absorption Research Articles

Nanotechnology in floriculture: Extending vase life and improving postharvest quality

Cut flowers are traditionally used worldwide, regardless of caste, creed, and religion, especially in Asian countries. The global trade of cut flowers has shown a substantial increase in recent years and is expected to persist due to the promotion and application of horticulture plants for their various advantages . The quality of vase life is critical in ensuring customer satisfaction and encouraging repeat purchases. Effective postharvest management is essential for enhancing the quality and extending the shelf life of cut flowers. With proper handling, cut flowers can last several days in a vase. Nanotechnology presents innovative solutions for postharvest management, especially in the cut flower sector. Specifically, Nanoparticles have been utilized in packaging to act as ethylene inhibitors and antimicrobial agents, contributing to the extension of cut flower vase life. One of the strongest ethylene perceptions is 1-methylcyclopropene (1-MCP), a gaseous and nontoxic that binds to ethylene receptors irreversibly, blocking the action of ethylene. Nano-Silver particles improve postharvest longevity by increasing water absorption rather than transpiration. Additionally, Nano-Selenium enhances the water balance in cut flowers. This review describes how nanoparticles suppress microbial growth and block ethylene action in cut flowers, extending their vase life.

Thermal and hygrometric performances, and mold growth resistance, of novel bio-stitched insulating fiberboards made from date and Washingtonia palm surface fibers

This paper evaluates the performance of a novel bio-stitched, lightweight insulating fiberboards made from Phoenix dactylifera L. and Washingtonia filifera palm fiber waste. These materials are binder-free, rendering them fully biodegradable. In this study, measurements are made of water sorption and its impact on density and thermal conductivity. Both materials exhibited insulating properties, with thermal conductivity values ranging from 0.043 to 0.063 W.m−1.K−1 depending on density. The bio-stitched fiberboards achieved their lowest thermal conductivity at an optimum density of 85–105 kg.m−3. The results indicate also that the thermal conductivity and density of bio-stitched fiberboards increase significantly with volumetric water content. However, even at saturation, they retain competitive thermal insulation properties. The residual fibers used were subjected to different natural weathering durations. Three types of fiber were therefore evaluated: one fresh, one moderately weathered and the other extremely weathered, in an attempt to compare the hygrothermal properties of the elaborated fiberboards as a function of fiber conditioning. It was found that Washingtonia palm surface fiberboards have higher water absorption compared to weathered date palm surface fiberboards. In addition, mold growth was evaluated by exposing the fiberboards to severe relative humidity conditions, i.e., 74 % RH, 77 % RH, 86 % RH, and 94 % RH at 29ºC. It was observed that the proliferation of mold was slow, particularly on weathered fiberboards, while it remained moderate on the surface of fresh Washingtonia palm surface fiberboards.

Liquid-Water Transfer Coefficients of Porous Building Materials Under High-Humidity Conditions

The moisture transfer coefficient is a key parameter for analyzing the moisture-based physical properties of materials and studying the heat–moisture coupling process within building envelopes. The liquid-water transfer coefficient, as an important aspect of this process, plays a significant role, especially under high-humidity conditions. However, the global research on liquid-water transfer coefficients is still far from complete. To further enhance the research on liquid-water transfer coefficients, this study conducted capillary water absorption experiments on seven traditional and new porous building materials, focusing on testing the moisture transfer coefficients, primarily the liquid-water transfer coefficient. A novel analysis regarding the impact of sealing materials was proposed, based on the experimental results. Based on the experimental data, the concept of a critical value related to the variation in the capillary moisture content and the liquid-water diffusion coefficient was raised, and, building upon traditional empirical models, a completely new computational model was proposed. Data processing was carried out using methods such as variability analysis, correlation analysis, and nonlinear regression for model fitting. The research findings indicate the following: (1) The capillary water absorption rate and capacity of a material are influenced by its density and porosity. (2) In terms of sealing materials, self-adhesive films performed better than non-adhesive films. (3) The concept of critical capillary moisture content was proposed, based on the rate of change in the liquid-water diffusion coefficient. For the threshold of w ≤ 80%, a new calculation model with a higher correlation coefficient was proposed which can meet the calculation requirements of the diffusion coefficient under the vast majority of relative-humidity conditions.

Feasibility of coal bottom ash as fine aggregate in strain-hardening cementitious composites: A study on strength, durability, and sustainability

The search for cost-effective and sustainable materials for strain-hardening cementitious composites (SHCC) has led researchers to explore alternatives to silica sand, a critical yet costly and environmentally unfavorable material. Although river sand seems like a cheaper and viable alternative, its extraction is linked to severe environmental degradation. This study aims to investigate the potential of coal bottom ash (CBA) as a replacement for silica sand in SHCC, targeting to meet the minimum requirements for structural applications. The novelty of this research lies in its comprehensive exploration of CBA as a partial to full replacement for silica sand (at 0 %, 25 %, 50 %, 75 %, and 100 %), extending beyond the replacement limit investigated in previous studies on SHCC, and provides an extensive evaluation of the composite’s fresh, mechanical, durability, and microstructural properties. Additionally, it includes a thorough assessment of the leaching potential, CO₂ emissions, energy consumption, and cost implications of the CBA-SHCC, which have not been fully explored in earlier CBA-SHCC research. The findings indicate that the reduction in mechanical strength was minimal (0.5 %-10 %) across all CBA replacement levels. Notably, all mixes demonstrated typical strain-hardening behavior, sustaining higher flexural loads beyond the first crack, with increased deflection capacity observed at higher CBA contents, peaking at 50 % replacement. Durability metrics, including water absorption and HCl acid attack resistance, exhibited a downward trend with higher CBA content but remained within acceptable limits up to 75 % replacement. Toxicity characteristic leaching procedure results confirmed the non-leachability of toxic elements in both the CBA and CBA-SHCC mixes. Economically and environmentally, CBA proved advantageous, resulting in 1.5–5 % lower CO2 emissions, 0.4–1.5 % lower energy consumption, and 18–84 % cost savings at 25–100 % CBA replacement. Additionally, a multicriteria analysis using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed, which identified 25 % as the optimal CBA content that balances fresh properties, mechanical strength, durability, environmental sustainability, and cost efficiency. The study is significant because it demonstrated that CBA can be used as a sustainable and cost-effective alternative to silica sand in SHCC, with lower environmental impact while maintaining structural integrity.

Effect of Different Admixtures on Mechanical Properties of Concrete Paving Block: A Comparative Study

Ever since their introduction nearly a century ago, concrete paving blocks have become increasingly common. They evolved into an alternative to burned clay brick and natural stone. Concrete paving blocks are used to lay down areas for vehicles and pedestrians as well. Durability is one of the most crucial elements in the production of high-quality concrete paving blocks. The aim of this study is to optimize the mechanical properties of concrete paving block units by experimenting with different admixtures. Compressive strength, water absorption, oven dry density, and drying shrinkage are among the attributes that were evaluated. The cost of production was also contrasted with and without the use of an admixture to achieve a comparable compressive strength. The results showed that admixtures could be used to produce high early strength units, and this was considered to be an economical factor in the production of concrete paving block units. At all ages, the use of admixtures increased these units' compressive strength by 30–40%. Although they did slightly increase density, additives also decreased the absorption and drying shrinkage of concrete paving block units.

Mechanical, wear, fatigue, water absorption and flammability of silane-treated Indian squid chitin powder-dispersed pineapple fiber-polyester composite

Mechanical, wear, fatigue, water absorption and flammability of silane-treated Indian squid chitin powder-dispersed pineapple fiber-polyester composite

Effect of recycled concrete powder on the rheological properties of cement paste: New findings

Recycled concrete powder (RCP) influences cement paste's rheology, but the mechanisms remain unclear. This paper intends to fill this gap by employing a new method for measuring water absorption, the minimum water requirement method, an organic carbon analyser, and a laser particle size analyser. The cementitious material's water absorption (W), packing density (φm), water reducer adsorption (Qad), and particle size distribution are determined. Results show that, as the RCP's content increases from 0 % to 25 %, the cementitious material's W, φm, Qad, volume fraction, and average particle size increase by 21.7 %, 0.9 %, 26.2 %, 1.4 %, and 30.6 %, respectively. Consequently, the particle's surface covered by the water reducer (θ) and distance (H) decrease by 26.5 % and 32.6 %, respectively, resulting in an increase in the paste's yield stress (τ0) and plastic viscosity (ηpl) by 1946.6 % and 45.3 %, respectively. Based on an existing yield stress model, RCP affecting τ0 can be attributed to changes in the particle system's colloidal and contact interactions. A decrease in H increases colloidal interactions. Conversely, an increase in φm and a decrease in fine particle content reduce contact interactions. Colloidal interactions are more significant, thus τ0 increases. Based on the functional expression for the ηpl developed here, RCP affecting ηpl can be attributed to changes in hydrodynamic interactions and contact interactions. A decrease in H increases hydrodynamic interactions. An increase in φm combined with a decrease in fine particle content decrease contact interactions. Additionally, an increase in Qad reduces pore solution's viscosity. Hydrodynamic interactions are more significant, thus increasing ηpl.

Adhesion performance of furfurylated plywood bonded with polyurethane and epoxy adhesives

Utilizing furfurylated veneers to improve the quality of plywood has not been extensively studied before. This study investigated the characteristics of plywood made from furfurylated rubberwood (Hevea brasiliensis) veneers at various modification levels. Rubberwood veneers were first impregnated with furfuryl alcohol (FA) at different concentrations (40%, 70%, and 100%) with 3% citric acid as a catalyst for FA polymerization at 103 °C. The weight percent gain (WPG), dynamic mechanical analysis (DMA), and functional groups of the furfurylated veneers were analyzed. The furfurylated veneers were then used to form three layers of plywood using either polyurethane (PU) or epoxy resin as the adhesive. Various physical, mechanical, and morphological properties of the furfurylated plywood were characterized. The WPG of the veneers impregnated with 40%, 70%, and 100% FA were on average 32.2%, 54.1%, and 67.9%, respectively. DMA and ATR-FTIR analyses revealed differences between the control veneers and the furfurylated veneers. Furfurylation slightly decreased the bonding strength of PU-bonded plywood at 100% FA, while the epoxy-bonded plywood remained unchanged at all FA concentrations. Furfurylation reduced the delamination values of plywood, particularly for treatments with 40% and 100% FA. Moreover, the use of 100% FA reduced the thickness swelling, water absorption, and leaching values of the plywood after seven days of water immersion by 43.6%, 73.9%, and 73.8% with PU adhesive, and by 85.7%, 69.6%, and 80.2% with epoxy adhesive, respectively. The formation of furfurylated plywood in this study opens potential opportunities for using low-quality veneers from fast-growing wood species as substitutes for high-quality veneers from natural forests.

Rheological, mechanical and durability properties of mortar containing brick waste as a partial replacement of sand

The investigation presented in this paper focuses on the feasibility of employing brick waste (BW), a byproduct of limestone, to make self-compacting mortar (SCM). The principle goal of this study contributes in increasing economic and environmental value by replacing sand with co-products and optimizing their handling and management. Six alternative mortar mix proportions, including BW at rates of 0 %, 5 %, 10 %, 15 %, 20 %, and 25 %, are tested for rheological properties (flow time, yield stress and viscosity), the mechanical (compressive strength and flexural strength), durability (water absorption/porosity, chloride penetration, sulfate resistance and SEM analysis). The deep in visitation showed that a SCM with a yield stress of 13.8 Pa, a 25 % BW replacement rate, and a viscosity of 11.7 Pa.S may reach a flow time of 74.2–64.1 S. In addition, mortars containing 25 % BW had a maximum compressive strength and flexural strength of 36.9 MPa and 4.03 MPa at 28 days, representing an 11.3 % and 39.2, respectively drop over the reference mortar BW0 %. The results showed the water absorption and the depth of chloride penetration increased by 86.2 % and 36 %, respectively. The sulfate resistance was decreased by 39 % as compared to those of the reference mortar (BW0 %). Scanning Electron Microscopy (SEM) observations showed that the BW25 % mortar contains several pores compared to those of BW10 % and BW0 %.

Correction to: Mechanical, thermal conductivity, and water absorption properties of biosilica and palm kernel fiber reinforced epoxy composite rebar for building materials

Correction to: Mechanical, thermal conductivity, and water absorption properties of biosilica and palm kernel fiber reinforced epoxy composite rebar for building materials

The effect of infrared-assisted thermal and hydrothermal treatments on low-quality wheat flour obtained from tail-end passages and cracker quality

Low-quality wheat flour (LQF) is a by-product with high nutritional value but poor shelf life and technological properties. In this study, infrared (IR)-assisted thermal and hydrothermal treatments were applied to stabilize LQF and improve its functional properties. For the hydrothermal treatments, LQF was adjusted to 15%, 20%, 25%, and 30% moisture content. Samples were processed at 800 W IR emitter power until moisture content dropped below 8%.While the treatments had little effect on the core composition of the flour, they led to an increase in its maximum, final, and setback viscosities. Thermal treatment increased water absorption and solvent retention capacity, shortened dough development time (DDT), and did not affect extensibility. Hydrothermal treatments, however, led to an increase in extension resistance and DDT. The 15% initial moisture content improved dough stability and extensibility, but these characteristics declined at higher moisture levels.In crackers produced from the treated flours, increasing initial moisture levels improved the spread ratio, though moisture levels of 25–30% reduced hardness and created a brittle texture. These findings revealed that varying initial moisture levels allowed for selective modifications in the stabilization of LQF, with acceptable changes in color and composition.

Improvement of overall quality of black rice by stabilization combined with solid-state fermentation

The application of black rice in food industry is challenging due to its short shelf life, poor cooking and eating quality. Superheated steam (SS) and far infrared radiation (FIR) are effective ways of stabilization and might be beneficial to solid-state fermentation (SSF). Therefore, stabilization treatments (SS and FIR) combined with SSF by Aspergillus oryzae were applied to furtherly improve the overall quality of black rice in present study. Results indicated that combined treatments were more favorable to shorten cooking time, increase water absorption and solid loss, resulting improvement of cooking quality of black rice. Besides, the significant decrease in hardness and chewiness after combined treatments was also good for the texture improvement. Moreover, black rice after combined treatments showed significantly higher contents of free phenolics, flavonoids, antioxidant activities, and phenolic acids, while their contents in bound form were significantly decreased, leading to significant increase of nutritional properties. Furthermore, black rice after combined treatments had significantly lower acid value and peroxide value during accelerated storage. Particularly, far infrared radiation combined with SSF was the most valued to improve the overall quality of black rice. These improvements were mainly ascribed to the enhancement of hydrolase activities based on the synergistic effect between stabilization treatments and SSF, which led to more significant pasting viscosities decrease, crystal structure destruction, cell wall rupture and starch degradation. The above results will provide a favorable strategy to improve the overall quality of black rice and then promote its consumption and application in food industry. Industrial relevanceThe short shelf life, poor cooking and eating quality severely limit the utilities of black rice in food industry. Heat processing is one of the most efficient strategies used in food industry to improve quality and prolong shelf life. Superheated steam and far infrared radiation are typical innovative heating technologies, and they are more energy efficient and more effective than conventional heating methods. In our previous work, they were effective ways of stabilization to extend the shelf life of black rice, and the starch after above treatments was partially gelatinized, which might be beneficial to the solid-state fermentation and thereby furtherly improve the overall quality of black rice. The present study aims to provide a favorable strategy to improve the overall quality of black rice and then promote its consumption and application in food industry.

3D Bioprintable Self-Healing Hyaluronic Acid Hydrogel with Cysteamine Grafting for Tissue Engineering

The abundance of hyaluronic acid (HA) in human tissues attracts its thorough research in tissue regenerating scaffolds and 3D bioprintable hydrogel preparation. Though methacrylation of HA can lead to photo-crosslinkable hydrogels, the catalyst has toxicity concerns, and the hydrogel is not suitable for creating stable complex 3D structures using extrusion 3D bioprinting. In this study, a dual crosslinking on methacrylated HA is introduced, using cysteamine-grafted HA and varying concentrations of 2-hydroxy ethyl acrylate. The resultant hydrogel is suitable for extrusion 3D printing (or bioprinting), mechanically robust, self-standing, stable in phosphate-buffered saline at 37 °C for more than 42 days, has high water absorption capacity with a low swelling ratio (1.5), and exhibits self-healing and adhesive properties. Complex 3D structures like ears and pyramid shapes with more than 2 cm of height are 3D printed using the optimized composition. All the synthesized hydrogels have shown nontoxicity and cell-supportiveness. Loading of cells, tetracycline, and bovine serum albumin into the hydrogel led to better bioink properties such as cell attachment, growth, and proliferation for osteoblast cells. The test results suggest that this hydrogel is biocompatible and has potential for 3D bioprinting of self-standing structures in bioink form in tissue engineering and regenerative medicine.

Chloride ingress and carbonation assessment of mortars prepared with recycled sand and calcined clay-based cement

A promising and economical route for the reduction of the environmental impact generated by Ordinary Portland Cement (OPC) and Construction and Demolition (C&D) waste could be possible using Recycled Sand (RS) with Limestone Calcined Clay Cement (LC3). This research study presents an experimental investigation based on the comparison between LC3 and CEM II binders mixed with natural sand and two types of recycled sand (substitution rate 50 vol%). Mechanical and durability properties of the different mortars were examined through compression and flexural strength tests, capillary water absorption, Mercury Intrusion Porosimetry (MIP), fog chamber salt spray exposure and immersion in chloride solution condition to evaluate water-soluble and acid-soluble chloride contents, and carbonation assessment by natural and accelerated methods. According to experimental results, LC3 containing 70 % of clinker and a calcined clay to limestone ratio of 2:1 exhibits superior compressive strength compared to CEM II for both natural and recycled sands and significantly enhances the resistance against chloride ions ingress and carbonation. These results demonstrate that LC3 binder with 70 % clinker is a promising material to produce LC3 blends with adequate durability against carbonation and chloride ions ingress, particularly when recycled sand is used as a source of fine aggregate.

The experimental substantiation of the main parameters of the extraction of gaillardia herb (Gaillardia pulchella L.)

In the structure of the pharmaceutical market, the share of drugs based on the medicinal plant raw material (MPRM) is growing. Therefore, it is relevant to create a standardized domestic substance of natural origin – a liquid extract of gaillardia herb (Gaillardia pulchela L.) and develop new medicines based on it. Aim. To obtain a liquid extract by experimentally substantiating the main parameters of gaillardia herb extraction. Materials and methods. The study object was the raw material of gaillardia herb collected in the flowering phase at the Botanical Garden of the Poltava National Pedagogical University named after V. G. Korolenko (Poltava) in July and August 2022-2023, dried by the air-shade method and crushed by the rolling method. The crushed raw material was sifted through a sieve with a hole size of 10 mm. The millet was used for further research. The study of pharmaco-technological indicators was carried out according to the standard methods of the SPhU. Results and discussion. Since the complex of active substances of gaillardia herb was mainly represented by water-soluble BAS, it was necessary to choose a solvent that would remove this group of substances from the raw material as completely as possible. The experimental data obtained show that the ability to extract the BAS complex from gaillardia herb is preferred by purified water, which provides the maximum yield of extractive substances. The next stage of our research was to study the determination of the multiplicity of extraction, based on the determination of the maximum yield of extractive substances. Each of the extracts was selected fractionally with a step of DER 1:1 (drug extract ratio – the ratio of the starting material to the resulting extract). According to the data obtained, the amount of extractives passing during the extraction into the hood increases gradually up to 5 samples. Analyzing extracts from 6 to 10, it can be seen that the amount of extractives and a dry residue varies slightly; percolation with the extraction of more than 5 will lead to an increase in the consumption of the extractant and a decrease in the yield of active substances for the entire volume of the extractant. Conclusions. Based on the results of the studies conducted, the technological parameters of gaillardia herb have been determined (the volume mass – 0.453 ± 0.016 g/cm3; the bulk mass – 0.071 ± 0.001 g/cm3, the specific gravity – 1.214 ± 0.032 g/cm3, the water absorption coefficient – 1.68 ± 0.08). It has been experimentally proven that when extracting with purified water, the maximum yield of extractive substances is observed in the second volume, the yield of extractive substances is smooth, without sharp fluctuations in concentrations (in contrast to 40 and 70% ethanol). Therefore, the studies have determined an effective extractant for obtaining the extract, namely purified water. As a result of the pharmaco-technological tests conducted, the effective multiplicity of gaillardia herb extraction has been determined, which is equal to 5. The data will be taken into account when developing the technology of a liquid extract from gaillardia herb and choosing equipment for its production.

Optimizing Hempcrete Properties Through Thermal Treatment of Hemp Hurds for Enhanced Sustainability in Green Building

This study examines the effects of the thermal pre-treatment of hemp hurds on the physical, mechanical, and thermal properties of hempcrete, evaluating its potential as a sustainable building material. Hemp hurds were pre-treated at various temperatures (120–280 °C) and characterized by proximate analysis, CHNS elemental analysis, and thermogravimetric analysis (TGA). The resulting hempcrete samples were analyzed for density, water absorption, compressive strength, and thermal conductivity. Three different hempcrete formulations, with varying lime:hemp proportions, were analyzed. The findings indicate that higher pre-treatment temperatures lead to reduced density and water absorption across all formulations. Formulations containing a higher hemp hurd content had lower densities but higher water absorption values. Compressive strength increased consistently with the pre-treatment temperature, suggesting that higher temperatures enhance matrix bonding and structural rigidity, and with the lime content. However, thermal conductivity also rose with pre-treatment, with only the composition containing the highest hemp hurd content maintaining the optimal insulation threshold (0.1 W/mK). This suggests a trade-off between compressive strength and insulation performance, influenced by the balance of hemp hurd and lime content. These findings underscore the potential of thermal pre-treatment to tailor hempcrete properties, promoting its application as a durable, moisture-resistant material for sustainable building, though the optimization of hurd–lime ratios remains essential.

Comparative study of physical and mechanical properties of a light plaster mortar based on the "SPADAR" foam ceramic granules and similar light fillers

Introduction. Plasters are still one of the most popular materials for finishing of facades of buildings. Modern plasters are produced mainly in the form of ready-to-use dry mixes. Manufacturers set themselves the task of obtaining not only plaster mixtures meeting standards, but also having hydrophobicity, low density, thermal conductivity and other features that determine the functionality of the plaster coating. In this regard, there is a need to develop and implement plaster mixtures based on new types of light aggregates. Aim. To conduct comparative studies of the physical and mechanical properties of a light plaster mortar using the "SPADAR" foam ceramic granules and plaster mortars with similar fillers as a light filler. Materials and methods. The research was carried out on light plaster mortars using as light fillers: "SPADAR" and foam ceramic granules from another manufacturer ("KERWOOD"), foam glass granules, expanded perlite sand. The parameters of density, strength under axial compression, water absorption during capillary suction and thermal conductivity of a light plaster mortar in a dry state were studied. The tests were carried out according to standard methods. Results. The comparative technical characteristics of the studied plaster compositions are determined. During the analysis of the data obtained, the advantages of plaster compositions using foam ceramic granules as a light filler were revealed. Based on the data obtained, the composition of a light plaster mortar with a density of up to 700 kg/m3 using the "SPADAR" foam ceramic granules was developed. Conclusions. The composition of the plaster based on the "SPADAR" foam ceramic granules turned out to be the most effective by the obtained values of the studied characteristics in total. In many ways, the obtained values of the technical characteristics of this plaster studied in this work are provided precisely by the "SPADAR" foam ceramic granules. Based on the results obtained, it is necessary to investigate other properties of the developed compositions of light plaster mixtures (adhesion, vapor permeability, moisture-proof properties with respect to the mineral base, frost resistance, etc.).

Porous aggregate developed with the use of coal-containing clays of the Angren field

Relevance. One of the ways to solve the issues of resource and energy conservation is the production and use of porous aggregates. Porous aggregates allow obtaining effective lightweight concrete for thermal insulation, wall panels, monolithic walls and other load-bearing structures, contribute to the increase of energy efficiency, improvement of thermal insulation, reliability, increase of fire resistance, frost resistance and seismic resistance of buildings, reduction of their weight. Therefore, in the production of porous aggregates, the primary task is the use of industrial waste and products of their processing. Solving these problems leads not only to saving valuable natural resources, but also to solution of environmental problems. Aim. Development of compositions and study of properties of porous aggregate based on bentonite clay of Navbakhar deposit and coal-containing clay of Angren brown coal deposit. Object. Coal-containing clay of Angren brown coal deposit, bentonite clay of Navbakhar deposit and artificial porous aggregate based on them. Methods. Chemical, energy-dispersive X-ray, X-ray phase and infrared spectroscopic analysis, scanning electron microscopy, mathematical modeling, etc. Results. The authors have determined chemical and mineralogical compositions of the clays used. Using the mathematical modeling method they developed the regression equations describing the effects of the amount of bentonite clay in the batch, firing temperature and isothermal holding time on the bulk density and water absorption of the porous aggregates. The resulting porous aggregates with a bulk density of 395 to 690 kg/m3 have a compressive strength in a cylinder of 2.74 to 6.46 MPa, respectively. It was found that the aggregates obtained meet the requirements of regulatory documents.

Highly Performing Polysaccharide Hydrogels can Replace Acrylic Acid‐Based Superabsorbent Polymers in Sanitary Napkins

AbstractSuper absorbent polymers (SAPs) used in sanitary napkin are not required for water absorption capacity as high as in baby diapers and adult incontinence pads. Sanitary napkins must absorb menses, which is delivered at a significantly lower rate and overall daily amount than urines. Thus, the acrylic acid (AA) component can not be strictly necessary. By proper formulation design and processing, polysaccharide SAPs can be equally or even better performing than AA‐containing SAPs in sanitary napkins. Fully biodegradable sodium alginate (SA)‐based SAPs are prepared through ionic cross‐linking by CaCl2 and introduced in female pads. The optimal solution concentrations (SA 8% w/v, CaCl2 0.25% w/v in water) and reaction time are identified, and addition of cellulose nanocrystals (CNC) at different weight contents (0–3 w%) is tested. Morphology, physico‐chemical properties, rheology, free swelling capacity (FSC), centrifuge retention capacity, and weight loss in soil are assessed. Increasing CNC content decreases FSC. Rheology results demonstrate higher storage and loss moduli for SA‐based SAPs versus commercial SAPs. The superior SA‐SAP developed is used in varying amounts for manufacturing sanitary napkin prototypes, revealing that excellent menstrual fluid absorption, surpassing commercial pads. Replacing AA‐based with polysaccharide‐based SAPs would reduce the environmental impact of hygienic product waste.

Synthesis of naringenin schiff base loaded CMC/PVA scaffold as biodegradable wound care materials

Abstract The complex formula of wound care therapy includes effective treatment tactics, infection prevention, wound preconditioning, and germ therapy. By creating ideal circumstances for wound healing, wound dressings are a major factor in lowering the rate at which infections worsen. The persistence of chronic wounds as a significant healthcare challenge necessitates the creation of innovative wound-dressing techniques. This work describes a novel method for creating ternary biodegradable polymers from polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC). With the addition of Naringin Schiff base, the aqueous mixture of CMC and PVA creates an ideal wound dressing material. The base of Naringin Schiff possesses strong antibacterial and antioxidant characteristics. The goal of this work is to create polymer based on polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) loaded with Naringin Schiff base for efficient wound care therapy. The 1H, 13C NMR, FT-IR, and Mass spectrometry were used to characterize the Schiff base. The Schiff Base loaded CMC/PVA film was characterized by FT-IR, AFM. Studies such as biodegradability, antimicrobial studies, water absorption capabilities, water vapour transmission rate and dressing pH of the films were also conducted. The promise of biopolymers as better wound dressing material will be highlighted in this work, allowing more efficient wound care.