Water Absorption Research Articles

Experimental Study on Workability, Strength & Durability of Geopolymer Concrete with use of Fly ash, Ground Granulated Blast Furnace Slag & Silica Fume

Abstract: Geopolymer concrete, crafted from a blend of Fly Ash, GGBS, and Silica Fume activated by sodium silicate and sodium hydroxide, demonstrates excellent workability and strength over time. It proves resilient against acid, chloride, water absorption, and carbonation, making it a sustainable choice for construction projects seeking durability and performance. These qualities position geopolymer concrete as a promising alternative to traditional concrete methods.

Geopolymer Paving Blocks Made From Fly Ash and Bagasse Ash Under Different Curing Conditions

This research aimed to study the geopolymer paving blocks made from fly ash and bagasse ash under different curing conditions. The fly ash was replaced by bagasse ash at 10, 20 and 30% by weight of the binder. Sodium hydroxide and sodium silicate solutions were used as activated solutions. Three curing methods were studied: curing with plastic wrap (PT), curing at 35 °C for 1 hour (OV), and curing with sunlight (SU). Compressive strength and water absorption were investigated. The surface characteristics of the geopolymer paving block were studied using microstructure techniques. Sun curing provided the highest compressive strength. The water absorption values increased with an increase in the replacement percentage of bagasse ash. The surface of the geopolymer paving blocks showed remnants of the starting materials from the reaction. The geopolymer paste from the geopolymerization reaction was also found. This indicated the beneficial use of waste materials to produce environmentally friendly building materials.

Fabrication and Characterization of Natural Fiber-Polymer Composites for Prosthesis Socket Application

ABSTRACT A natural fiber-reinforced composite from a locally available false banana plant is developed for a prosthesis socket application. Four batches of composite samples are fabricated by arranging the longitudinal uniformly distributed unidirectional false banana fibers in four orientations (0°, 90°, ±45°, 0°/90o). The composites’ mechanical and physical properties, such as tensile strength, compression strength, flexural strength, impact resistance, and the effect of chemical treatment on water absorption, are investigated. The results are compared with E-glass fiber-reinforced polymer matrix composite. The false banana fiber-polymer composites with a 0° fiber orientation have a tensile strength of 86.81 MPa, less than 9% lower than E-glass-fiber composites (95.44 MPa), and an impact resistance of 6.25 J, 10% higher compared to the E-glass fiber polymer composites (5.70 J). In addition, the treated false banana fiber-polymer composite absorbed 70% less water than the untreated false banana fiber-polymer composite. It is observed that the fiber treatment has increased the polymer–fiber interaction and the interface strength of the false banana fiber-polymer composites.

Extrusion of Rice and Aronia melanocarpa Pomace: Physical and Functional Characteristics of Extrudates

In this study, black chokeberry (Aronia melanocarpa) juice pomace was used to enrich the extrudates from rice in order to create a functional food. A response surface methodology was applied to optimize the physical (expansion ratio, bulk density, moisture content, hardness, pellet durability index, and color) and functional (water solubility index, water absorption index) characteristics of the extrudates. A laboratory single-screw extruder was used to produce the extrudates and a full factorial experimental design was applied (N = 32) to present the effect of the amount of chokeberry pomace (10 and 20%), the feed moisture content (14 and 20%) and the working screw speed (180 min−1 and 220 min−1) of the extruder on the physical and functional characteristics. The results showed that the three factors influenced all studied characteristics. An exception with statistically insignificant effect was the amount of chokeberry pomace on the expansion ratio, pellet durability index, water adsorption index, lightness, redness, and yellowness, the feed moisture content on the water solubility, water adsorption index, redness and yellowness, and the working screw speed on the bulk density and hardness.

Evaluation of physicochemical properties of Rohu fish noodles

Functional noodles are considered nutritious and healthy staple food products. This study aimed to develop value-added rohu fish noodles (Labeo rohita) and evaluate their physicochemical properties. Six noodle samples were prepared following several formulations. After a 2-day drying process, the noodles were stored in air-resistant plastic bags. The formulated noodles were investigated based on their physical (water absorption capacity, cooking loss, and volume increase) and chemical (moisture, ash, protein, fat, and fiber) properties. Statistical analysis revealed that the inclusion of rohu fish mince significantly increased moisture and protein content (p<0.01), while carbohydrate, energy, water absorption capacity, cooking loss, and volume decreased significantly (p<0.01). Noodles with the highest fish mince content (30%) demonstrated a higher amount of moisture (13.07%), ash (6.7%), fat (1.87%), protein (30.08%), sodium (0.64 mg), and calcium (0.26 mg), accompanied by reduced carbohydrate (48.3%) and energy (330.31 kcal). This formulation also exhibited lower water absorption capacity, cooking loss, and volume. Notably, no significant differences (p>0.05) were found in ash, fiber, fat, and mineral content among the various fish noodle samples. This study concludes that the incorporation of rohu fish mince can enhance the nutritional properties of traditional noodles.

Optimization of preparation conditions and performance of a new degradable soil water retaining agent

Using polyaspartic acid (PAsp) and bentonite (BT) as the main raw materials, a new type of degradable soil water retaining agent (PAsp-AA/BT) was synthesized by microwave radiation. The optimum synthesis conditions and comprehensive properties of PAsp-AA/BT were discussed and the structure and surface characteristics of PAspsp-AA/BT were characterized by FTIR, SEM, XRD and TGA in the paper. The results showed that the optimum synthesis conditions of PAsp-AA/BT were as follows: the dosages of polyaspartic acid (PAsp), bentonite (BT), initiator potassium persulfate, crosslinking agent N,N′-methylene bisacrylamide was 5, 3, 0.3, 0.03%, respectively, the neutralization degree of acrylic acid was 75%, and the microwave power was 490W. Under this condition, the absorption ratio of the synthesized PAspsp-AA/BT in deionized water and 0.9% NaCl solution was 953 and 164 g/g, respectively. The synthesized PAsp-AA/BT had a high water absorption rate, good water retention and repeated water absorption, and the degradation rate in soil within 30 days reached 32.75%, with good degradation effect. The analysis of SEM, FT-IR, XRD and TGA showed that: the surface of PAsp-AA/BT was rough and had obvious pore structure, which was conducive to the diffusion of water molecules; polyaspartic acid, bentonite and acrylic acid were polymerized; the cross-linking structure was formed between polyaspartic acid, bentonite and acrylic acid; the product of PASP-AA/BT had good thermal stability. This study provides a new soil water retaining agent, which is helpful for the better development of soil water retaining agent research.

A novel starch‐based composite hydrogel enhanced by activated charcoal from the banana peel for water decontamination

AbstractThe efficient removal of potential toxic elements (PTEs) from aqueous systems is an important challenge in water purification and industrial effluent treatment. Starch‐based hydrogels have shown promise in this context due to their unique properties, such as high absorption capacity and water retention. This work synthesized a novel hydrogel with and without activated charcoal (AC) from banana peel (5 wt.%) and trisodium citrate as a crosslinking agent and starch to remove PTEs. These hydrogels were characterized by Fourier‐transformed infrared (FTIR), scanning electron microscopy, TGA, XRD, water absorption, and zero‐charge point techniques. Subsequently, the affinity of AC, neat hydrogel, and the composite hydrogel for removing Cr6+, Cd2+, Ni2+, Mn2+, Zn2+, and Cu2+ in aqueous solution was evaluated. FTIR confirmed a crosslinking reaction between the starch molecules and the crosslinking agent (trisodium citrate). Besides, the addition of hydrogel+5%AC altered the crosslinking process. Adding AC to the hydrogel composite increased crystallinity, thermal stability, and porous size. The highest removal efficiency of neat hydrogel and hydrogel+5%AC was for Cr6+, obtaining 83.2% and 98.5%, respectively. As for the AC, the removal of Cu2+ was satisfactory, with 80.4%. Thus, hydrogel+5%AC proves to be a highly viable adsorbent for posttreatment of wastewater due to its ability to efficiently remove PTEs.

Thermodynamical Analysis of the Distillation Column for Targeting Minimum Energy in Ammonia–Water Absorption Refrigeration Cycle

In this study, a comprehensive method to optimize distillation columns in ammonia–water absorption refrigeration, power, and cogeneration cycles is introduced. The novelty of this work lies in a comprehensive analysis of the distillation column's thermal performance and the introduction of a new design framework that maximizes heat integration. Key findings include the critical role of the solution heat exchanger, especially at lower generation and evaporation temperatures. Using a saturated liquid or two‐phase feed can achieve up to 80% efficiency at a feed composition of 0.3. Moreover, in the results, the substantial potential for improving the coefficient of performance (COP) through strategic design is highlighted. Notably, minimizing the pinch point temperature difference to 0 °C can boost the COP by 6%, while optimal feed placement can increase it by 9%. Incorporating feed preconditioning and side exchangers can lead to a 22% COP enhancement, indicating the significance of heat integration to the distillation column. In this study, a graphic guideline for selecting cycles that can achieve a minimum of 10% COP improvement without introducing unnecessary complexity is delivered and it suggests that distillation columns can be simplified by using a combination of separators, heaters, and coolers in certain cases.

Enhancing Wet Starch Noodle Properties: Investigating the Impact of Acetylated and Ozonized Sago (Metroxylon sago Rottb.) Starch

This study explores the impact of ozonation and acetylation on sago starch, targeting improvements in noodle production. Functional properties were examined, including water content, water absorption index (WAI), water solubility index (WSI), and amylose content. Ozonation generally decreased water absorption (from 18.32% in native sago (NS) to 18.29% in ozonated sago (OS)) and solubility (from 12.39% in NS to 15.2% in OS). Conversely, acetylation increased solubility (from 19.04% in acetylated sago (AS) to 17.55% in ozonated-acetylated sago (OAS)). Modifications reduced amylose content (from 31.67% in NS to 23.13% in AS), impacting noodle texture and physiochemical properties. Modified sago starch noodles cooked faster but absorbed less water, resulting in higher cooking loss. For instance, cooking time decreased from 5 minutes (NS) to 6 minutes (AS), while water absorption decreased from 90.22% (NS) to 75.42% (AS). Additionally, cooking loss increased from 19.39% (NS) to 12.04% (AS). Pasting properties were affected, with increases observed in trough viscosity (TV), breakdown (BV), and final viscosity (FV). For instance, TV increased to 2758.5 RVU in OAS compared to 1903 RVU in AS. Modified sago starch noodles showed faster cooking times, lower water absorption, and higher cooking loss. Texture profile analysis (TPA) indicated softer textures for modified noodles, possibly due to enhanced expansion after modification.

Preparation and Properties of Attapulgite-Hydroxyethyl Cellulose Composite Poly (Acrylic Acid-co-2-acrylamide-2-methylpropanesulfonic Acid) Concrete Internal Curing Material

Attapulgite-hydroxyethyl cellulose-poly (acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid) (ATP-HEC-P(AA-co-AMPS)) in-concrete curing material was synthesized by aqueous solution polymerization using attapulgite (ATP) as an inorganic filler and hydroxyethyl cellulose (HEC) as a backbone. The effects of relevant factors such as ATP dosage, HEC dosage, degree of neutralization, initiator quality, and cross-linking agent quality on the water absorption characteristics of ATP-HEC-P (AA-co-AMPS) were investigated through expansion tests. The micro-morphology of ATP-HEC-P (AA-co-AMPS) was also comprehensively characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, a thermal analysis, and other applicable means. The results showed that the prepared ATP-HEC-P (AA-co-AMPS) had a strong water absorption and water retention capacity, with a water absorption multiplicity of 382 g/g in deionized water and 21.55% water retention capacity after being placed at room temperature for 7 d in a bare environment. Additionally, ATP-HEC-P (AA-co-AMPS) showed good performance for absorbing liquids within the pH range of 7–12. The material’s thermal stability and mechanical properties were also significantly improved after the addition of ATP. The preparation cost is low, the process is simple, and the material meets the requirements for concrete curing materials.

Production and Characterization of Recycled Polypropylene Composite Reinforced with Cotton Fabric Waste

Composite materials have played an important role throughout human history, from housing early civilizations to enabling future innovations. This study explores the development of composite materials from recycled polypropylene and cotton fabric waste targeted for different applications. The composites were manufactured by the melt-mixing method. The effects of cotton fabric waste content on various composite characteristics were investigated using tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, compressive strength, and water absorption. The study showed that with an increase in cotton fabric waste content, properties such as tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and compressive strength increase up to the optimum level, while a decrease in these properties is observed after the optimal level. The maximum tensile strength of 57.84 MPa, tensile modulus of 1.31 GPa, flexural strength of 55.32 MPa, flexural modulus of 2.7 GPa, impact strength of 33.06 kJ/m2, and compressive strength of 53.68 MPa were obtained. The water absorption rate increased with an increase in the cotton fabric waste weight proportion. From the result of this study, it can be concluded that the optimal mechanical and water absorption properties were achieved at 30% cotton fabric waste content. Therefore, creating composites from recovered polypropylene and cotton fabric waste can have both environmental and financial benefits.

Synthesis and characterisation of hydrogel based on propiolic acid

ABSTRACT In this study, using a propiolic acid monomer and ammonium persulphate as initiator and N,N’-methylenebisacrylamide as crosslink agent, poly propiolic acid hydrogel was designed and tested for water absorption. Also, to investigate the effect of pH on hydrogel’s efficiency, swelling was investigated at different pH levels. To obtain the optimal formula for hydrogel with maximum water absorption, the initiator and crosslink agent levels were changed. The obtained data showed that the highest conversion rate of monomer to polymer was observed for the S1 sample with an initiator concentration of 10% by weight and a crosslinking agent with a concentration of 2% by weight. It also has the highest water absorption for this sample and its swelling rate is 27.6 times that of dry hydrogel. Increasing the concentration of the crosslinking agent and reducing the amount of initiator resulted in the reduction of hydrogel swelling in water. Also, the swelling rate of samples at different pH shows that reducing pH to acidic environments or increasing it to basic environments led to a decrease in network swelling in all three samples. Finally, to investigate the structure and morphology of hydrogels, FTIR, SEM, and measuring the amount of hydrogel swelling at ambient temperature tests were used.

A comparative study assessing the validity of water absorption methods when applied to secondary fine aggregates

The valorization of secondary sands is crucial for fostering a circular economy within the construction sector. One significant obstacle in this endeavor stems from the high water absorption (WA) rates commonly reported for secondary sands. This high WA leads to increased water and cement demand in cementitious mixes and elevates costs. The only widely standardized method to measure the WA of fine aggregates is the cone method, which has proven ill-suited for fine aggregates with angular particles or a high content of fines. This study undertakes a comparative evaluation of the cone method and seven alternative methods: immersion, centrifugation, paper sheet, colorimetric, volumetric flask, continuous drying, and electrical conductivity. Tests were performed on natural river sand and three types of secondary sand. Findings reveal that the continuous drying and electrical conductivity methods demonstrates the greatest potential in terms of reliability and applicability. Also the volumetric flask and centrifugation methods show some potential, provided that critical refinements are made to the corresponding test protocols.

Effect of DBSA‐doped PANI on the corrosion protection performance of GO/epoxy coatings

AbstractIn this study, the anticorrosion effect of polyaniline doped with dodecyl benzene sulfonic acid (PANI‐DBSA) in graphene oxide (GO)/epoxy coating is investigated. PANI‐DBSA is effectively synthesized on the surface of GO via chemical polymerization, and its properties are investigated via a series of characterization methods. The PANI‐DBSA/GO hybrid exhibits improved compatibility with organic resin. The anticorrosion performance of PANI‐DBSA/GO coatings is assessed through water absorption tests, electrochemical impedance spectroscopy measurements, and adhesion strength tests. The results indicate that PANI reduces the water absorption of GO, and the favorable compatibility of PANI‐DBSA/GO with epoxy resin minimizes coating defects and enhances the interfacial blocking for diffusion electrolytes. In this work, the PANI has no active function such as passivating the metal surface, it just serves to shield the hydrophilic GO surface and to improve compatibility between GO and the epoxy, attributing its low pigment content.

PH responsive THPS crosslinked injectable hydrogel with Cu-metformin sustained-release for accelerating wound healing

The utilitarian capacity of hydrogels in fostering a conducive milieu for cellular viability renders them a compelling alternative to conventional wound dressings. Nonetheless, the uncontrolled drug release exhibited by numerous drug-loaded hydrogel dressings often undermines their capacity for sustaining therapeutic efficacy over prolonged periods, while certain hydrogel formulations prove inadequate for addressing deep-seated wounds with low pH caused by chronic bacterial infections. Within the scope of this investigation, a novel pH-responsive injectable sustained-release hydrogel is developed through the crosslinking of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) with carboxymethyl chitosan (CMCS) and Ɛ-poly-L-lysine (EPL). This innovative hydrogel manifests rapid gelation within a span of 30 s sans the requirement of a catalyst, alongside demonstrating commendable antibacterial attributes facilitated by the incorporation of a Cu-metformin complex (CuMet). Furthermore, the lyophilized hydrogel exhibits exceptional water absorbency and hemostatic qualities, effectively addressing exudative concerns and mitigating blood loss. In vitro assessments ascertain the higher drug release under acidic conditions and sustained drug release potential of CMCS/EPL/CuMet for up to 120 h, concomitantly expediting wound healing processes through the attenuation of bacterial colonization and inflammatory responses. In summation, this investigation furnishes novel insights into the viability of the developed formulation as a sustained-release injectable wound dressing.

Influence of HPMC on the capillary water absorption, pore structure and hydration of the calcium aluminate cement-hemihydrate gypsum mortar

Influence of HPMC on the capillary water absorption, pore structure and hydration of the calcium aluminate cement-hemihydrate gypsum mortar

Rising Damp Treatment in Historical Buildings by Electro-Osmosis: A Case Study

Throughout the past century, numerous technologies have been suggested to deal with the capillary rise of water through the soil in historic masonry buildings. The aim of this study was to examine the effectiveness of capillary moisture repulsion apparatus that uses the electro-osmosis approach over a prolonged period of time. The Gül mosque was selected as a sample historical building affected by structural problems caused by the absorption of water through small channels on its walls due to capillary action. The moisture repulsion mechanism efficiently decreased the moisture level in the walls from a ‘wet’ state to a ‘dry’ state in roughly 9 months. After the installation of the equipment, the water mass ratio of the building decreased from 14.48% to 2.90%. It was determined that the majority of the water in the building was relocated during the initial measurement period. Furthermore, it inhibited the absorption of water by capillary action by protecting the construction elements that were in contact with the wet ground. Lastly, capillary water repulsion coefficients (C) for various measurement durations and time factors were proposed. The average value of C was calculated to be 0.152 kg/m2 s0.5 by measuring the point at which the water repulsion remained nearly constant.

Effect of hydrophobic materials on alkali-silica reaction-induced deterioration of mortar: A comparative study

The deterioration of mortar or concrete caused by the alkali-silica reaction (ASR) significantly depends on its susceptibility to moisture imbibition and exposure. This study investigated how applying hydrophobic materials in cement mortar prevents ASR-induced deterioration. Three hydrophobic materials were used, including a hexamethyldisilazane (HMDS) treated fumed-silica, a silane-based emulsion, and a silane-based cream. These hydrophobic materials were applied by directly coating the aggregates before mortar preparation or added directly to the mixture as admixtures. The effect of the applied hydrophobic materials on mortar properties was evaluated based on compressive strength, dynamic modulus, water absorption, and linear expansion. Furthermore, the microstructure and ionic distribution of alkalis from the aggregates interface were appraised using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) tests. The results were compared to a mortar with no admixtures and a mortar with 20% cement replaced by fly ash (a traditional method of ASR mitigation). Coating aggregates with hydrophobic fumed silica were more effective at reducing ASR-induced expansion than directly integrating the hydrophobic materials, although at a lower degree than fly ash.

A Review on Utilization of recycled Aggregate in concrete: Examining the effects of incorporating recycled concrete aggregate or other recycled materials as substitute for natural aggregate in concrete mixtures

In developed countries, concrete is mostly observed as a valuable resource. Recycling efforts have highlighted the importance of maintaining the required compressive strength when using old concrete in new construction. Research shows that compressive strength depends on factors like adhered mortar, water absorption, abrasion resistance, aggregate size, original concrete strength, curing time, replacement ratio, transition zone between old and new concrete, moisture level, impurities, and environmental conditions. While some studies have suggested methods for adopting recycled aggregates into concrete mixes, there's a need for a simple and environmentally friendly approach that considers the percentage of adhered mortar. This project aims to review existing literature on using recycled concrete as aggregates, focusing on compressive strength, and propose a method for incorporating recycled concrete aggregate while maintaining strength. Keywords: Construction and demolished concrete, second generation concrete, Adhere, recycling, workability, recycle aggregate, compressive strength

Mechanical and Water Barrier Properties of Inhomogeneous Clay Nano-Particles Reinforced Thermoplastic Starch

This research investigated the development of biodegradable bioplastic as a possible replacement for petroleum-based plastics, which constitute a serious environmental hazard. These hazards include but are not limited to flooding resulting from blocked sewage and danger to aquatic life in marine environments. The solution casting method was used to blend inhomogeneous kaolinite clay nano-particles with distilled water, starch, dilute acetic and nitric acids to produce different compositions of thermoplastic starch (TPS)/Clay composites with clay reinforcements ranging from 2.5 to 10 wt.%. The composites were characterized using an X-ray diffraction (XRD), and the mechanical and water absorption properties were determined. The result revealed a 9-fold improvement in the tensile strength (0.72 MPa), flexural strength increased 5-fold (3.34 MPa), and hardness increased 2-fold (23.56 HVN) as well as a reduction in water absorption by 3-fold (6.63%) when compared to the control. Furthermore, the 10 wt.% clay content composite showed the highest mechanical properties. The significant improvement in the listed properties was attributed to a reduction in crystallinity and the formation of new chemical bonds between the thermoplastic starch and the nano-clay. It was observed that the properties of the composites can be further enhanced if a synchronized machine blender (such as an extruder) is employed.