Water Absorption Research Articles

Thermal modification of fast-growing Firmiana simplex wood using tin alloy: Evaluation of physical and mechanical properties

Wood is an important structural material, but some undesirable properties limit its application in construction. This study investigated the effect of tin alloy thermal modification (TTM) on selected physical and mechanical properties of Firmiana simplex (Chinese bottletree) wood. Tin alloy thermal modification of F. simplex was performed in a tin alloy bath at two different temperatures (150 oC and 210 oC for 2 h and 8 h). Physical properties such as swelling, water absorption and density and mechanical properties like modulus of elasticity, modulus of rupture, impact bending, compression strength and Brinell hardness of tin alloy thermal modified and control samples were evaluated. The results showed that tin alloy thermal modification decreased the swelling of the wood to 4,85 %, 1,45 % and 6,99 % along the tangential, radial and volumetric coefficient and water absorption and density decreased to 53,10 % and 290 kg/m3 respectively compared to the control. Modulus of elasticity, modulus of rupture, impact bending, compression strength and Brinell hardness of tin alloy thermal modified F. simplex at 210 °C for 8 h decreased to 6366,1 MPa, 54,9 MPa, 2,7 MPa, 29,4 MPa and 1113,5 MPa respectively compared to the control. In conclusion, the tin alloy thermal modified wood at 210 oC significantly affected the physical and mechanical properties of the wood.

Recovery of mining and agri-food wastes in fired materials: a case study of the Moroccan industry.

The linear economy follows the "take-make-dispose" model and generates huge amounts of waste without consideration for recycling or reuse. This model which deals with raw materials puts pressure on natural resources and creates a serious environmental impact. In a circular economy, the "reduce-reuse-recycle" model is applied to recycle waste into resources and reduce the impact on the environment and society. This work aims to highlight the significance of implementing a circular economy approach in the construction sector by merging two different production lines, notably mining activity and agri-food industry. The investigation presents sustainable management of coal mine waste (CMW) and olive pomace (OP) in the production of eco-friendly fired materials and introduces an innovative approach for manufacturing lightweight fired bricks. Microstructural, physical, mechanical, and thermal properties were determined to evaluate the technological quality of fired materials at 900°C. As a pore-forming agent, adding 10 wt% OP yielded specimens with a bulk density of 1552kg/m3, water absorption of 19.80%, apparent porosity of 29.61%, loss on ignition of 26.98%, and compressive strength of 7.08MPa, satisfying standards for clay masonry units. Simultaneously, it enhances the thermal insulation by reducing thermal conductivity by 18% compared to the control sample with CMW. In this regard, the transition to a greener construction sector necessitates the immediate implementation of a circular economy approach to developing eco-friendly building materials by recovering large amounts of industrial waste, limiting the overuse of natural resources (e.g., clays), and improving the engineering properties of the final product.

Enhanced Photocatalytic Activity in Photocatalytic Concrete: Synthesis, Characterization, and Comprehensive Performance Assessment of Nano-TiO2-Modified Recycled Aggregates

This study presents an exhaustive exploration into the development and rigorous evaluation of nano-TiO2-modified recycled aggregates (NT@RAs) as an environmentally sustainable substitute for natural aggregates in concrete applications. A methodical framework was devised for the synthesis and thorough characterization of NT@RAs, emphasizing the optimization of nano-TiO2 loading onto the RA surface and within its intricate porous structure. The investigation encompassed three distinct types of recycled aggregates: recycled glass sands (RGSs), recycled clay brick sands (RCBSs), and recycled concrete sands (RCSs). Of particular interest, NT@RGS, with its properties of an inherently smooth surface texture and low water absorption, was found to exert a favorable influence on the rheological behavior of concrete, manifested in reduced yield stress, thereby underscoring the potential for fine-tuning mix designs to enhance workability. As the substitution levels of NT@RGS and NT@RCBS escalated, an initial decrement in compressive strength was discernible, which subsequently reversed to strength restoration at optimized substitution ratios. This phenomenon is attributed to the synergistic interplay among NT@RA components. Remarkably, NT@RA-incorporated concrete demonstrated unparalleled self-cleaning abilities, surpassing the performance of concrete with direct nano-TiO2 powder incorporation. This comprehensive research contributes significantly to the advancement in sustainable, high-performance photocatalytic construction materials within the realm of concrete technology. It underscores the potential for enhancing not only the rheological and mechanical properties but also the environmental responsiveness of concrete through the innovative utilization of NT@RAs.

Recycling of RAP (Reclaimed Asphalt Pavement) as aggregate for structural concrete: experimental study on physical and mechanical properties

The replacement of natural aggregate in concrete with artificial and/or recycled one has recently gained attention as meaningful strategy to reduce the environmental impact of structural concrete and promote circular economy principles. This study investigated the possibility to use Reclaimed Asphalt Pavement (RAP), in the “as received conditions”, as a partial or complete substitution of natural aggregate for structural concrete. RAP aggregate was firstly characterized in terms of grain size distribution, density, assessment of fines, chloride content, moisture content and water absorption. Subsequently, a total of twenty-four concrete mixes were designed, considering two cement types, two w/c ratios and several aggregate substitution percentages. For each mix, properties at the fresh and hardened state were investigated, such as workability, density and total open porosity, compressive strength, dynamic modulus of elasticity, and electrical resistivity. Results showed that RAP has a good potential to be used in reinforced concrete, provided that different water absorption and moisture content are considered in the mix design. RAP concrete was characterized by a lower density and increased total open porosity; however, an accurate tailoring of the concrete recipe could compensate the strength loss for several applications. Other properties, such as electrical resistivity and the relationship between dynamic modulus of elasticity and compressive strength did not result significantly altered by the presence of RAP.

Enhancing refrigerated chicken breasts preservation: Novel composite hydrogels incorporated with antimicrobial peptides, bacterial cellulose, and polyvinyl alcohol

Microbial contamination annually leads to substantial food resource loss. Effective food packaging can mitigate food contamination and waste, yet conventional materials such as plastics often lack bacteriostatic activity. This study aimed to synthesise FengycinA-M3@bacterial cellulose@polyvinyl alcohol composite hydrogels via dual cross-linking with hydrogen and borate bonding, with the goal of enhancing antibacterial properties and prolonging the preservation period of refrigerated chicken breast. The composite hydrogel was subjected to comprehensive characterisation for structural, mechanical, water absorption, slow peptide release, antimicrobial capacity, biocompatibility, and chicken breast freshness preservation. The results showed that the composite hydrogel had a porous network structure and excellent gel elasticity and biocompatibility. It was effective in inhibiting Staphylococcus aureus and Escherichia coli, and prolonged the storage time of frozen chicken breast for up to 12 days. These findings emphasise the potential of hydrogel food packaging to prolong storage periods and its suitability for food industry applications due to ease of manufacture.

Enhancing antifungal and antibacterial properties of denture resins with nystatin-coated silver nanoparticles

Long-term oral health issues caused by fungi and bacteria are a primary concern for individuals who wear dentures. Denture stomatitis, primarily caused by Candida albicans (C. albicans), is a prevalent condition among denture users. Metal nanoparticles exhibit improved antimicrobial effectiveness and fewer adverse effects. This study aimed to evaluate the antifungal and antibacterial effects of nystatin-coated silver nanoparticles (Nys-coated AgNPs) embedded in acrylic resin as a more biocompatible material for denture resins. AgNPs and Nys-coated AgNPs were synthesized and characterized using UV-Vis, SEM, EDX, and DLS. Specimens of polymethyl methacrylate (PMMA) with three different concentrations of Nys, AgNPs, and Nys-coated AgNPs (0.1%, 1%, 10% w/w) were prepared. The water absorption properties of the disks and drug release were investigated for 14 days and 120 h, respectively. The hydrophilic and hydrophobic properties of the samples and their contact angles were evaluated using the sessile drop technique. The antifungal and antimicrobial activity of the prepared discs was studied against C. albicans and Streptococcus mutans, respectively. Adding Nys-coated AgNPs decreased the contact angle of discs from 67° to 49°. Furthermore, the water absorption rates of the different discs were not significantly different from those of the control groups. Results showed that Nys-coated AgNPs (10% w/w) in PMMA effectively inhibited C. albicans growth better than Nys composites (10% w/w). Additionally, Nys-coated AgNPs composites, as well as AgNPs-containing composites, showed considerable antibacterial activity against S. mutans. Nys-coated AgNPs (10% w/w) had no toxic effect on NIH3T3 cells. In conclusion, Nys-coated AgNPs could be considered a good candidate for incorporation into denture resins to address chronic oral diseases.

Underwater image restoration via attenuated incident optical model and background segmentation

Underwater images typically exhibit low quality due to complex imaging environments, which impede the development of the Space-Air-Ground-Sea Integrated Network (SAGSIN). Existing physical models often ignore the light absorption and attenuation properties of water, making them incapable of resolving details and resulting in low contrast. To address this issue, we propose the attenuated incident optical model and combine it with a background segmentation technique for underwater image restoration. Specifically, we first utilize the features to distinguish the foreground region of the image from the background region. Subsequently, we introduce a background light layer to improve the underwater imaging model and account for the effects of non-uniform incident light. Afterward, we employ a new maximum reflection prior in the estimation of the background light layer to achieve restoration of the foreground region. Meanwhile, the contrast of the background region is enhanced by stretching the saturation and brightness components. Extensive experiments conducted on four underwater image datasets, using both classical and state-of-the-art (SOTA) algorithms, demonstrate that our method not only successfully restores textures and details but is also beneficial for processing images under non-uniform lighting conditions.

Colorimetric chitosan/polyvinyl alcohol composite membrane incorporated with anthocyanins as pH indicator for monitoring fish freshness

AbstractDuring storage, food undergoes transformations, often producing volatile nitrogen compounds known as total volatile basic nitrogen (TVB‐N), which serves as an indicator of food freshness. In this study, chitosan (CTS) was blended with polyvinyl alcohol (PVA) and incorporated with anthocyanins (ACNs) to monitor the quality changes in fish fillets over different time intervals. The results demonstrated that the presence of PVA in the CTS membrane enhanced light transmittance and reduced water absorption due to the reinforcement of the membrane structure through chemical interactions. In the freshness monitoring experiments, the CTS/PVA membranes exhibited an improved value of total color difference (ΔE), facilitating better detection of pH changes of the surrounding environment. Moreover, the ΔE value of the CTS/PVA film was observed to be quite similar to the value at pH 9 after 24 h and at pH 11 after 36 h when the fish fillet was stored at 25°C. In contrast, the ΔE value of the CTS/PVA film closely matched the value at pH 11 after 96 h of storage at 4°C. Additionally, the correlation between the generated TVB‐N and the ΔE values indicated a higher correlation coefficient (R2) for the composite membranes compared to the pristine CTS or PVA membranes.

The Use of Waste Synthetic Hair Fibre in Cement Mortar

Cement mortar has low tensile strength and fracture strain; therefore, fibres are used to reinforce cement mortar. Synthetic hair is one of the most neglected of all the residual wastes that cause environmental problems in many developing countries. Therefore, this study used waste synthetic hair fibre in cement mortar production as a way to reduce the environmental effect generated by waste, and also to enhance the strength of the mortar for construction application. The study aimed to investigate the properties of cement mortar reinforced with waste synthetic hair fibres. 0, 2.5, 5, and 7.5% of synthetic hair fibre were used as a replacement for cement by weight in mortar. 100 × 100 × 100 mm cube, and 100mm diameter and 200mm length cylinder specimens were prepared, cured, and tested at ages 7, 14, and 28 days for tensile and compressive strengths, density, and water absorption. The highest compressive strength for the synthetic waste hair fibre reinforced mortar was 8.57N/mm2 as compared to 10.84N/mm2 achieved for the control at 28 days of curing. The synthetic waste hair fibre reinforced mortar achieved the highest tensile strength of 1.80N/mm2 as compared to 1.67N/mm2 achieved by the control at 28 days of curing, representing an increase of about 11% in tensile strength of the synthetic hair fibre reinforced mortar over the control. The highest density for the synthetic hair fibre reinforced mortar was 2114 kg/m3 as compared to the control of 2144 kg/m3. The lowest water absorption for the synthetic hair fibre reinforced mortar was 2.48% as compared to the control of 2.04%, respectively. It is concluded that the properties of cement mortar reinforced with waste synthetic hair fibres are acceptable for construction application and recommended that practitioners use 2.5% waste synthetic hair as a partial replacement for cement in producing mortar.

NIR-II Anti-Stokes Luminescence Nanocrystals with 1710 nm Excitation for in vivo Bioimaging.

Anti-Stokes luminescence (ASL) based on lanthanide nanocrystals holds immense promise for in vivo optical imaging and bio-detection, which benefits from filtered autofluorescence. However, the current longest emission and excitation wavelengths of lanthanide ASL system were shorter than 1200 nm and 1532 nm, respectively, which limited tissue penetration depth and caused low signal-to-noise ratio (SNR) of in vivo imaging due to tissue scattering and water absorption. In this work, we extended the excitation wavelength to 1710 nm with the second near-infrared (NIR-II, 1000-1700 nm) emission up to 1650 nm through a novel ASL nanocrystal LiYF4:10%Tm@LiYF4:70%Er@LiYF4. Compared with 1532 nm excited ASL nanoprobes, the 1710 nm excited nanocrystals could improve in vivo imaging SNR by 12.72 folds. Based on this excellent imaging performance of the proposed ASL nanoprobes, three-channel in vivo dynamic multiplexed imaging was achieved, which quantitatively revealed metabolic rates of intestinal dynamics and liver enrichment under anesthetized and awake states. This innovative ASL nanoprobes and dynamic multiplexed imaging technology would be conducive to optimizing dosing regimen and treatment plans across various physiological conditions.

Sodium alginate-g-polyacrylamide hydrogel for water retention and plant growth promotion in water-deficient soils

Natural polymer-based hydrogels are preferred as soil water retention agents due to their inherent biocompatibility and biodegradability. Generally, these natural polymers are chemically modified by graft polymerization of vinyl monomers to improve their water absorption and retention properties. Among the polysaccharides used to prepare natural hydrogels, those based on sodium alginate (Alg) stand out for their high-water absorption and retention capacity, as well as for their ability to promote plant growth. The main objective of this study was to develop a biodegradable alginate-based hydrogel as a water retainer to promote plant growth under water deficit conditions. The synthesis was achieved by grafting poly(acrylamide) (PAM) onto Alg backbone, using bisacrylamide as chemical crosslinker and different ratios of alginate:acrylamide (Ac). In addition, Eucalyptus nitens seedlings were used as a model plant to evaluate the effect of alginate-g-polyacrylamide (Alg:PAM) hydrogel application to the growing medium on plant survival, growth, and physiological responses under both well-watered and water-deficient soil conditions. The maximum degree of swelling (65 g/g) was obtained for the hydrogel prepared. The pseudo-second order model described the water uptake kinetics of the hydrogel. The degradability of Alg:PAM hydrogel reached up to 85 % in 5 weeks in soil and occurs by breaking the glycosidic bonds of the alginate. The E. nitens seedlings cultivated with different doses of Alg:PAM hydrogel (4:1 Alg:Ac) showed higher values of height and root diameter relative growth, survival and photosynthetic responses in comparison to non-treated plants. The results indicate that Alg:PAM hydrogel (4:1 Alg:Ac) has promising applications in forestry as a water retention and seedling growth promoter under water deficient conditions.

Compressive stress-strain response of freshly compressed rubberized concrete: An experimental and theoretical study

Although using crumb tire rubber concrete (CTRC) in constructing structural elements is accompanied by various environmental and economic advantages, it always comes with challenges due to a significant loss in some mechanical properties of this concrete type. To tackle this challenge, a novel technique of compressing fresh concrete was used, and its impacts on improving the mechanical features of CTRC were investigated. For this purpose, concrete specimens containing crumb tire rubber (CTR), as the fine aggregate substitute, were constructed considering the variables of the water-to-cement ratio (w/c), volume percentage of CTR, and the fresh concrete pressure level as a fraction of steel tube (mold) yielding stress. After the application of a specified short-term pressure to the fresh mix inside the steel molds and the time required for the concrete setting, the steel tubes were removed after curing, and the concrete core alone was exposed to an axial compressive load. According to the test results, the mechanical properties, weight loss resulting from compressing the fresh concrete, energy absorption, failure pattern, the concrete microstructure, water absorption, and porosity were evaluated. By applying an initial axial pressure of 25–80 MPa on the mixes containing 0 %, 15 %, and 30 % CTR replacing the fine aggregate, the compressive strength, the ultimate strain, the toughness, and the initial modulus of elasticity experienced 100–140 % increase, 130–420 % increase, 120–1140 % increase, and 66–70 % decrease, respectively, compared with the uncompressed specimen. Finally, a regression analysis was employed to propose prediction models for the compressive capacity, modulus of elasticity, peak strain, ultimate strain, and relative toughness of freshly compressed concrete containing CTR particles; these models show proper agreement with the experimental results.

Exploring the effects of fiber content and length on mechanical, free vibration, electrical, and water absorption properties of Phoenix sp. fiber‐reinforced polyester composites

AbstractThis work addresses the experimental investigation of the mechanical, free vibration, electrical resistivity, and moisture uptake characteristics of Phoenix sp. fiber‐reinforced polyester composites (PFRPC) fabricated using the compression molding method. The polyester matrix (PM) was added with Phoenix sp. fibers (PSFs) of different content (5, 10, 15, 20, and 25 wt%) and length (10, 20, and 30 mm) and studied their effect on the aforesaid properties. The results reveal that the composites having 20 wt% of 20 mm length PSFs exhibited optimum mechanical properties. At this loading, the ultimate tensile strength and modulus were 48.36 MPa and 2.86 GPa, respectively, while the flexural strength and modulus were 83.89 MPa and 2.91 GPa, respectively. Furthermore, this composite exhibits an impact strength of 22.04 kJ/m2 and an interlaminar shear strength of 41.88 MPa. The increase in PSF content and length resulted in greater stiffness and decreased mass of the composites, leading to an enhanced natural frequency. The inclusion of PSFs showed a decline in electrical resistivities due to their moisture‐absorbing capability. In contrast, the hydrophilic behavior of PSFs led to a rise in the water absorption rate of the composites due to the increase in fiber variables. Scanning electron microscopy examination shows that short fiber‐reinforced composites have more fiber pull‐outs due to the limited area of contact, whereas long fiber‐added composites possess better bonding with the PM.Highlights Various properties of Phoenix sp. fiber/polyester composites were investigated Increase in fiber content enhanced the mechanical performance of composites Variation in fiber length has only minimal effect on composite properties Phoenix sp. fiber/polyester composites exhibit better insulating property

Variation in Thickness of Embryo Covering Structures and Their Role in the Regulation of Seed Physiological Dormancy of Chenopodium hircinum (Amaranthaceae)

Chenopodium hircinum, the putative wild ancestor of quinoa, is a source of traits that could improve the tolerance of crop quinoa to high temperatures. However, seeds of C. hircinum have physiological dormancy (PD), which is an obstacle for plant propagation and use in breeding programs. We studied the intraspecific variability in morpho-anatomical traits of embryo covering structures and their association with PD. We also evaluated the effects of different dormancy-breaking treatments on PD alleviation and germination. Seeds were dispersed with a remnant perianth and a persistent pericarp that could be removed by scraping. The seed coat was formed by palisade cells impregnated with tannins, and the seed contained a thin layer of peripheral endosperm surrounding the embryo. In our investigation, the thickness of the pericarp (P) and/or seed coat (SC) varied among populations. Populations with higher P and/or SC thickness showed lower percentages of germination and water absorption. The combined dormancy-breaking treatment (bleach + perforated coverings + gibberellic acid) promoted dormancy release and increased germination. C. hircinum seeds showed non-deep physiological dormancy. Based on previous knowledge about quinoa, and our results, we conclude that embryo coverings, especially the seed coat, have an important role in dormancy control, imposing a mechanical restraint on radicle emergence.

NIR‐II Anti‐Stokes Luminescence Nanocrystals with 1710 nm Excitation for in vivo Bioimaging

Anti‐Stokes luminescence (ASL) based on lanthanide nanocrystals holds immense promise for in vivo optical imaging and bio‐detection, which benefits from filtered autofluorescence. However, the current longest emission and excitation wavelengths of lanthanide ASL system were shorter than 1200 nm and 1532 nm, respectively, which limited tissue penetration depth and caused low signal‐to‐noise ratio (SNR) of in vivo imaging due to tissue scattering and water absorption. In this work, we extended the excitation wavelength to 1710 nm with the second near‐infrared (NIR‐II, 1000‐1700 nm) emission up to 1650 nm through a novel ASL nanocrystal LiYF4:10%Tm@LiYF4:70%Er@LiYF4. Compared with 1532 nm excited ASL nanoprobes, the 1710 nm excited nanocrystals could improve in vivo imaging SNR by 12.72 folds. Based on this excellent imaging performance of the proposed ASL nanoprobes, three‐channel in vivo dynamic multiplexed imaging was achieved, which quantitatively revealed metabolic rates of intestinal dynamics and liver enrichment under anesthetized and awake states. This innovative ASL nanoprobes and dynamic multiplexed imaging technology would be conducive to optimizing dosing regimen and treatment plans across various physiological conditions.

Impact of dehulling, germination and fermentation on the bioactive and functional properties of grey pea flour

IntroductionGrey pea is a largely overlooked legume in the Nordic countries, and its potential uses in various food products remain unexplored. It is a nutrient-rich crop with low environmental impact, making it an attractive option for sustainable and nutritious plant-based alternatives.ObjectivesTo investigate the impact of dehulling, germination, and fermentation on the bioactive (polyphenol content and antioxidant capacity) and functional characteristics (water absorption index, water solubility index, water and oil binding capacity, emulsifying properties and gelation concentration) of grey pea flour. Additionally, protein content and pasting properties (temperature, peak viscosity, trough viscosity, breakdown, final viscosity, and setback) were measured.MethodsDehulling was performed using a runner disk sheller. Germination was carried out for 24 and 48 h at ambient temperature, and fermentation was conducted for 8 h at 43°C using a starter culture.ResultsThe results indicate that dehulling did not significantly affect functional properties and gelling capacity (p = 0.297 for oil absorption capacity, p = 0.5 for emulsion activity, and p = 0.607 for emulsion stability), but it resulted in a notable decrease in total polyphenol content (TPC) and antioxidant capacity (TAC). Conversely, 48 h of germination increased TAC measured by two methods: FRAP (19%) and DPPH (30%). This process increased through viscosity by 1.2-fold, while it did not significantly affect the water absorption index (WAI), water solubility index (WSI), or the emulsifying properties of grey pea flour. Fermentation significantly improved TPC (p < 0.001 for whole grey peas and p = 0.004 for dehulled grey peas), with a TPC increase of up to 67% in fermented dehulled pea flour. TAC measured by both methods, showed significant increases, ranging from 35 to 104%. However, fermentation reduced emulsifying and pasting properties, as indicated by the peak, through and final viscosity, which may be desirable only for certain food products. Further, germination and fermentation showed significant increases in protein content, by 4 and 8%, respectively.ConclusionFermented grey pea flour exhibited enhanced bioactive characteristics, while 48-h germination positively impacted pasting properties. Overall, these processes led to changes in both the bioactive and functional properties of grey pea flour, creating opportunities for the use of these flours in a wide array of food products.

Performance Assessment of a Novel Green Concrete Using Coffee Grounds Biochar Waste

An actual scientific problem in current concrete science is poor knowledge of the problem of modifying concrete with plant waste. At the same time, plant waste benefits from other types of waste because it is a recycled raw material. A promising technological approach to modifying concrete with plant waste is the introduction of components based on the processing of coffee production waste into concrete. This study aims to investigate the use of biochar additives from spent coffee grounds (biochar spent coffee grounds—BSCG) in the technology of cement composites and to identify rational formulations. A biochar-modifying additive was produced from waste coffee grounds by heat treatment of these wastes and additional mechanical grinding after pyrolysis. The phase composition of the manufactured BSCG additive was determined, which is characterized by the presence of phases such as quartz, cristobalite, and amorphous carbon. The results showed that the use of BSCG increases the water demand for cement pastes and reduces the cone slump of concrete mixtures. Rational dosages of BSCG have been determined to improve the properties of cement pastes and concrete. As a result of the tests, it was determined that the ideal situation is for the BSCG ratio to be at a maximum of 8% in the concrete and not to exceed this rate. For cement pastes, the most effective BSCG content was 3% for concrete (3%–4%). The compressive and flexural strengths of the cement pastes were 6.06% and 6.32%, respectively. Concrete’s compressive strength increased by 5.85%, and water absorption decreased by 6.58%. The obtained results prove the feasibility of using BSCG in cement composite technology to reduce cement consumption and solve the environmental problem of recycling plant waste.

Mechanical, free vibration, electrical, and water absorption properties of vinyl ester composites reinforced with Phoenix sp. fibers: Influence of eco‐friendly sodium bicarbonate treatment

AbstractEnvironmentally sustainable and eco‐friendly natural fiber‐reinforced polymer composites have become the materials of interest in replacing synthetic fibers. However, weak interfacial interaction between hydrophilic natural fibers and hydrophobic polymer matrix limits their commercial applicability. Improving the interfacial interaction using environmentally friendly chemical treatments would be beneficial for both industries and the environment. In this study, vinyl ester‐based composites were made by incorporating Phoenix sp. fibers in different content (5, 10, 15, 20, and 25 wt%) and lengths (5, 10, 15, and 20 mm). To improve the interfacial interactions, the fibers were treated with eco‐friendly sodium bicarbonate solution at different durations (24, 120, and 240 h) prior to reinforcing. The fabricated composites were characterized by mechanical, free vibration, electrical resistance, and water uptake properties. The results reveal that both fiber content and fiber length have a significant effect on the above properties. Specifically, the composites incorporated with 20 wt% of 15 mm length fibers offered better properties. Further, the composites added with 120 h treated fibers have the maximum tensile strength (61.35 MPa) and modulus (4.13 GPa), flexural strength (152.63 MPa) and modulus (10.24 GPa), impact strength (24.67 kJ/m2), and natural frequency (56.72 Hz). This improvement is mainly due to the improved interfacial bonding, which was evidenced in morphological analysis. Based on the findings, the eco‐friendly treated sustainable Phoenix sp. fibers could be used as a promising reinforcement material for fabricating light weight polymer composites for various industrial applications.Highlights Various properties of Phoenix sp. fiber/epoxy composites were investigated. Interfacial bonding is enhanced through eco‐friendly chemical treatments. Vibration behavior of composites improved due to high stiffness of treated fibers. Composites with treated fibers have excellent electrical and water resistance.

Optimization and prediction of paver block properties with ceramic waste as fine aggregate using response surface methodology

The ceramic industry produces a significant volume of ceramic waste (CW), representing around 20–30% of its the entire output. The waste mostly comes from challenges noticed in the manufacturing process, overproduction, and damage to products. Considering the substantial worldwide production of ceramics, it is crucial to efficiently handle and recycle this waste to promote sustainability efforts. This study explores the conversion of ceramic waste into fine aggregates suitable for the production of paver blocks. Currently, a variety of assessments are being conducted to determine the effectiveness of these enhanced paver blocks. The evaluations involve aspects like compressive strength, water absorption (WA), dry density, flow table measurements, ultrasonic pulse velocity (UPV), and rebound hammer tests. The results indicate that replacing natural aggregates with up to 30% CW significantly improves compressive strength (CS) and Rebound results from tests. This study provides useful information into optimising the content of CW in paver blocks, contributing to the development of sustainable and economical construction materials. Furthermore, it focusses on minimising landfill waste and preserving natural resources.

Effect of water absorption on the properties of selective laser-sintered PA12 specimens

Effect of water absorption on the properties of selective laser-sintered PA12 specimens