Water Absorption Research Articles

Towards sustainable construction: Performance evaluation of slag-cenosphere geopolymers under different NaOH concentrations

The incorporation of industrial wastes into construction materials, such as geopolymers, is highly desirable to improve their environmental impact. The choice of source materials, such as slag and cenosphere, and the amount of activator used significantly impact the properties of geopolymers. For instance, including high-reactivity precursors and optimizing activator composition may enhance mechanical strength and durability. However, no studies have evaluated the effect of cenosphere addition on the properties of geopolymer composites. This research study aims to unveil the synthesis of a binary geopolymer material by integrating slag and cenosphere as precursors, activated by sodium silicate (Na2SiO3) and sodium hydroxide (NaOH). Geopolymer composites were prepared to assess the impact of cenosphere addition (by substituting the slag with cenosphere in different percentages of 25, 50, and 75 %) and NaOH concentration (specifically 6 M, 9 M, and 12 M) on the material's properties. Additionally, one conventional mortar with a water-to-cement ratio of 0.5 was also prepared. Compressive strength, ultrasonic pulse velocity (UPV), electrical resistivity, water absorption, density, and thermogravimetric analysis were conducted. Results showed that increasing the cenosphere percentage increased the water absorption and decreased the compressive strength, UPV, electrical resistivity, and density compared to the geopolymer mixture with 100 % slag content. However, up to 50 % substitution of cenosphere, the geopolymer mix performed better than conventional mortar. Notably, results suggest a potential increase in CO2 uptake due to the addition of cenosphere, further enhancing the environmental performance of geopolymer composites. The findings of this study suggest the potential use of slag-cenosphere geopolymer as an alternative and sustainable construction material.

The potential of new eco-friendly formulations in enhancing the protection of ceramic artifacts

This study focuses on transforming the consolidation formulations based on Hydroxypropyl cellulose (HPC), which is an eco-friendly bio-based cellulosic polymer with inherent hydrophilic characteristics to a hydrophobic one. This will be done via integrating the polymer with nano-silica and hydrophobic nano-silica, to enhance its consolidating properties to be in line with the global trend of replacing conventional materials with eco-friendly alternatives. Three different formulations were prepared, including HPC polymer solely, HPC integrated with nano-silica (NS), and HPC integrated with hydrophobic nano-silica (HNS). Primarily, nano-silica and hydrophobic nano-silica were synthesized and characterized using TEM and XRD. Subsequently, the prepared formulations were applied to artificial ceramic artifacts to evaluate their physical and mechanical properties, encompassing parameters such as water absorption, color change, contact angle, SEM/EDX, and digital microscopy. The results revealed that the incorporation of hydrophobic nano-silica significantly enhanced the mechanical and the physical properties of the cellulosic polymer, besides the extreme change that happened to its hydrophilic properties which was developed to a very good hydrophobic one. The success of these consolidation formulations can pave the way for the utilization of bio-based polymers with their inherent eco-friendly nature in the consolidation and restoration processes of cultural heritage artifacts, which can help in the contribution to the expanding body of knowledge in sustainable materials for conservation purposes.

Design and preparation of reticular superabsorbent hydrogel material with nutrient slow-release and high shear strength for ecological remediation of abandoned mines with steep slopes

In order to solve ecological remediation issues for abandoned mines with steep slopes, a kind of hydrogels with high cohesion and water-retaining were designed by inorganic mineral skeleton combining with polymeric organic network cavities. This eco-friendly hydrogel (MFA/HA-g-p(AA-co-AM)) was prepared with acrylic acid (AA)-acrylamide (AM) as network, which was grafted with humic acids (HA) as network binding point reinforcement skeleton and polar functional group donors, KOH-modified fly ash (MFA) as internal supporter. The maximum water absorption capacities were 1960 g/g for distilled water, which followed the pseudo-second-order model. This super water absorption was attributed to the first stage of 62 % fast absorption due to the high specific surface area, pore volume and low osmotic pressure, moreover, the multiple hydrophilic functional groups and network structure swell contributed to 36 % of the second stage slow adsorption. In addition, the pore filling of water in mesoporous channels contributed the additional 2 % water retention on the third stage. The high saline-alkali resistance correlated with the electrostatic attraction with MFA and multiple interactions with oxygen-containing functional groups in organic components. MFA and HA also enhanced the shear strength and fertility retention properties. After 5 cycles of natural dehydration and reabsorption process, these excellent characteristics of reusability and water absorption capacity kept above 97 %. The application of 0.6 wt% MFA/HA-g-p(AA-co-AM) at 15° slope could improve the growth of ryegrass by approximately 45 %. This study provides an efficient and economic superabsorbent material for ecological restoration of abandoned mines with steep slopes.

Study on Damaged Expanded Water-Repellent Perlite Insulation Integrating Neural Network and Simulation on Temperature field and Boil-off Rate in a Liquefied Natural Gas Cargo Containment

The temperature field and Boil-off Rate (BOR) of the cargo containment system (CCs) in the LNG (Liquefied Natural Gas) carrier are directly impacted by the thermal performance of insulation, which has an adverse effect on the structural safety and commercial feasibility of LNG transportation. However, the potential damage to hydrophobic layer of expanded perlite during the processes of filling, storage, and transportation can lead to undesirable increases in water absorption, thermal conductivity, even the risk of insulation failure. To investigate the variations in the thermal conductivity of damaged expanded water-repellent perlite used in CCs of LNG carrier, The variations in the thermal conductivity of expanded water-repellent perlite are tested using a guarded hot plate apparatus extending down to liquid nitrogen temperatures under the combined influence of moisture content and damage rates. Furthermore, heat transfer models are established, and the accuracy of the mathematical models is validated using experimental data collected from LNG carrier CCs. A Back-propagation Neural Network is used to conduct sensitivity analysis and predictions based on the experimental results. The results show that both the breakage rate and water content have detrimental effects on insulation performance. Specifically, under equatorial sailing conditions, 450mm-thick expanded water-repellent perlite show respective BOR increases of 22.8% and 116.4%. With 530mm-thick expanded water-repellent perlite, BOR increased by 20.7% and 112.1%, respectively, even exceeding the daily BOR limit for LNG cargo. Analyzing temperature field and BOR provides essential insight for evaluating the thermal insulation performance of the structural system in the NO 96 LNG carrier.

Valorization of the Residual Fraction of Coal Tailings: A Mineral Circularity Strategy for the Clay Ceramic Industry in the Carboniferous Region of Santa Catarina, Southern Brazil.

Mineral extraction of coal in the carboniferous region of southern Santa Catarina (Brazil) plays a significant role in the regional economy. However, this activity has severe environmental impacts, with approximately 65% of the extracted mineral being discarded as a rejected material (deposited in landfills). The identification of the technological potential of these materials, based on the geological aspects of the extraction site and the beneficiation operations applied to obtain coal, provides the opportunity to add value to different residual fractions that can be reused. Thus, waste valorization, the main objective of this work, has recently become a strategy for the application of these minerals in the production of clay ceramics using a systematic approach named CPQvA, which means "classification, potentiality, quantity/viability, and applicability". The use of these materials as secondary mineral sources can avoid the deposition of these materials in industrial landfills and help to reduce the pressure on landfills, which receive an average of four million tons of material annually. In this study, the residual fraction, part of the tailing from coal beneficiation, known as coal fines, was evaluated for formulation valorization in clay ceramics. This residual fraction was classified as non-hazardous (class II-A, non-inert). X-ray fluorescence spectrometry, X-ray diffraction, and thermogravimetric analysis were performed to characterize the moisture content, particle-size distribution, and coal content to be used in the development of different formulations using the residual fraction of coal tailings (ranging from 0 to 40%) that are of technological interest to the sector. Processing parameters, such as firing at different temperatures (750, 800, 850, and 900 °C), were also correlated with these formulations. The results were compared with those of a reference ceramic formulation from the local productive arrangement of Morro da Fumaça (Arranjo Produtivo Local Cerâmica Vermelha de Morro da Fumaça). The various relationships between the materials were characterized in terms of their thermal shrinkage, water absorption, and mechanical resistance. Leaching and solubilization environmental tests revealed that both the industrial standard formulation and formulations with the application of the residual fraction were classified as non-hazardous materials. Thus, the method of using a mining residual fraction in the formulation of clay ceramics proved to be beneficial for the circular economy in the regional mineral sector through productive and environmental gains; the primary mineral resource and energy consumptions and the impacts related to waste generation were reduced. The results of this study can be applied to similar situations in other parts of the world.

Effect of tannin and calcium lignosulfonate-based adhesives on particleboards production

Laboratory tests were carried out to evaluate the feasibility of producing particleboards with sugarcane bagasse and Eucalyptus sp. and adhesives (tannin pure and lignosulfonate (tannin + lignosulfonate in the proportion of 80:20)). The adhesives were characterized (pH, gel time, viscosity, and density), and the physical and mechanicals properties was realized (water absorption and thickness swelling, moisture content, gravimetric density, density profile by X-ray, elasticity and rupture modulus, and internal bond).The particleboards showed some homogeneity in density. As to the thickness swelling, the means varied from 24.15 % to 35.57 %, with higher averages for those particleboards that used lignosulfonate adhesive. The same effect could be seen in the water absorption test, with emphasis on the tannin-lignosulfonate adhesives, with averages 18.5 % higher than those of pure tannin, regardless of the type of material. Based on the internal bond test, the highlight was the treatment with 100 % wood particles and pure tannin adhesive. As sugarcane bagasse was added, there was a reduction in modulus of elasticity, independently of the adhesive used. The results highlighted the using lignosulfonate as a component obtained inferior results when compared to those of pure tannin, mainly concerning humidity and the internal bond test. As well as a gradual loss of strength as the wood was replaced by sugarcane bagasse. In this aspect, environmental issues are gained as waste is used; in such uses, such properties are not required.

Sustainable seedling pots: Development and characterisation of banana waste and natural fibre-reinforced composites for horticultural applications

Plastic pots used in horticultural nurseries generate substantial waste, causing environmental pollution. This study aimed to develop biodegradable composites from banana pseudo-stem reinforced with agricultural residues like pineapple leaves, taro and water hyacinth as eco-friendly substitutes. The aim of this study is to develop optimised banana biocomposite formulations with suitable reinforcements that balance mechanical durability, biodegradation, and seedling growth promotion properties to serve as viable eco-friendly alternatives to plastic seedling pots. This study was carried out by fabricating banana fibre mats through pulping, drying and hot pressing. Composite sheets were reinforced with 50 % pineapple, taro or water hyacinth fibres. The mechanical properties (tensile, yield strength, elongation, bursting strength), hydrophilicity (contact angle, water absorption), biodegradability (soil burial test), and seedling growth promotion were evaluated through appropriate testing methods. The results show that banana-taro composites exhibited suitable tensile strength (25 MPa), elongation (27 %), water uptake (41 %) and 82 % biodegradation in 60 days. It was observed that biodegradable seedling trays fabricated from banana-taro composite showed 95 % tomato seed germination and a 125 cm plant height increase in 30 days, superior to plastic trays. The finding shows that the study demonstrates the potential of banana-taro biocomposites as alternatives to plastic nursery pots, enabling healthy seedling growth while eliminating plastic waste pollution through biodegradation.

Antiadhesive, antibacterial, and anti-inflammatory sandwich-structured ZIF8-containing gauze for enhanced wound healing

Medical gauze is commonly used in clinical practice due to its low irritation, flexibility, and permeability. However, conventional gauze frequently lacks adequate antibacterial and anti-adhesion properties, and gauze that is only superhydrophobic or antibacterial seldom meets the full requirements of infected wound treatment. In this work, we report optimal air permeability, water and blood absorption, and biocompatibility, and effective antibacterial properties of a sandwich-structured gauze composed of a superhydrophobic outer layer, a zeolite imidazolate framework-8 (ZIF8) interlayer, and a superhydrophobic inner layer containing blood-drainage channels (denoted SZS gauze). Three ZIF8 interlayers, ZIF8-1, ZIF8-2, and ZIF8-3, were prepared by soaking medical gauze samples in a mixed solution of 50 mL methanol, 50 mL ethanol, and 0.25, 0.50, or 1.00 g zinc acetate before flat drying, and had Zn content of 0.28, 0.34, and 0.46at.%, respectively, and their corresponding SZS gauze samples are denoted SZS-1, SZS-2, and SZS-3, respectively. Among all gauze samples, the SZS-2 showed the highest cytocompatibility toward L929 cells and effective in vitro antibacterial ability against E.coli and S.aureus. In a rat subcutaneous inflammation model, the SZS-2 showed complete biosafety and the best antibacterial and anti-inflammatory effects against E.coli and S.aureus mixed bacteria among all gauze samples including standard medical gauze and a sandwich-structured gauze with a blank interlayer between two superhydrophobic layers. These findings indicate that the SZS-2 gauze is a promising candidate for advanced wound care, particularly in the management of infected wounds.

Heat-Induced Gelation of Chickpea and Faba Bean Flour Ingredients

This study aimed to investigate the gelling behavior of faba bean (FB) and chickpea (CP) flour between 10 and 20% (w/w) concentration at pH 3.0, 5.0, and 7.0. Both sources formed at pH 3.0 and 5.0 self-standing gels with 12% (w/w) of flour, while 16% (w/w) of flour was required to obtain a gel at pH 7.0. During gelling between 40 and 70 °C, a sharp increase of the elastic modulus G’ was observed in both flours, mainly due to water absorption and swelling of the starch, one of the major constituents in the ingredients. Increasing the temperature at 95 °C, G’ increased due to the denaturation of globulins and therefore the exposure of their internal part, which allowed more hydrophobic interactions and the formation of the gel. After cooling, both FB and CP gels displayed a solid-like behavior (tan δ ranging between 0.11 and 0.18) with G’ values at pH 3.0 and 5.0 significantly (p < 0.05) higher than those at pH 7.0, due to the lower electrostatic repulsions at pHs far from the isoelectric point. The rheological properties were supported by the water binding capacity values, confirming the better gels’ strength described by rheological analysis. These results will enhance our understanding of the role of legume flours in formulating innovative and sustainable food products as alternatives to animal ones.

Effect of Different Drying Methods on the Structure and Properties of Porous Starch

In order to investigate the effects of different drying methods on the properties of porous starch. The present study used four drying methods, namely hot air drying (HD), spray drying (SPD), vacuum freeze drying (FD) and supercritical carbon dioxide drying (SCD) to prepare maize and kudzu porous starch. Findings indicated that the physicochemical properties (e.g., morphology, crystallinity, enthalpy value, porosity, surface area and water absorption capacity as well as dye absorption capacity, particle size) of porous starch were significantly affected by the drying method. Compared with other samples, SCD-treated porous starch exhibited the highest surface areas of the starch (2.943 and 3.139 m2/g corresponding to kudzu and maize, respectively), amylose content (22.02 % and 16.85 % corresponding to kudzu and maize, respectively), MB and NR absorption capacity (90.63 %, 100.26% and 90.63 %, 100.26 %, corresponding to kudzu ad maize, respectively), and thermal stability, whereas HD-treated porous starch showed the highest water-absorption capacity (123.8% and 131.31 % corresponding to kudzu and maize, respectively). The dye absorption of the maize and kudzu porous starch was positively correlated with surface area, according to Pearson's correlation analysis. Therefore, in this study, our aim was to explore the effects of different drying methods on the Structure and properties of porous starch, and provide reference for selecting the best drying method for its application in different fields.

Non-destructive strategy to extract sustainable helix and high-strength Musa core fibers for rapid water conduction and evaporation

The reuse and development of natural waste resources is a hotspots and challenges in the research of new fiber materials and the resolution of environmental concern globally. Herein, this study aimed to develop a simple and direct manual extraction process to extract Musa core fibers (MCFs) for rapid water conduction and evaporation. Through simple processes such as ring cutting and stretching, this green and non-destructive inside-out extraction strategy enabled Musa fibers to be naturally and harmlessly degummed from natural Musa stems, with good maintenance of the fiber structure and highly helical morphology. The extracted fibers are composed of regularly and closely arranged cellulose nanofibrils in the shape of ribbon spirally arranged multi-filaments, and the single filament is about 2.65 μm. The high-purity fibers exhibit ultra-high tensile strength under a non-destructive extraction process, and the ultimate tensile strength in dry state is as high as 742.95 MPa. The tensile strength is affected by the number of fiber bundles, which shows that tensile strength and tensile modulus is higher than those of vascular bundle fibers in dry or wet condition. In addition, the MCFs membrane indicates good water conductivity, with a water absorption height of 50 mm for the sample in only 60 s. Moreover, the water evaporation rate of MCFs reaches 1.37 kg m−2 h−1 in 30 min, which shows that MCFs have excellent water conductivity and evaporation rate compared with ordinary cotton fibers. These results indicate that MCFs have great potential in replacing the use of chemical methods to extract fibers from vascular bundles, providing an effective way to achieve sustainability in quick-drying applications, as well as in the sustainable development of natural waste resources.

Preparation and properties of carbon dioxide foamed concrete using nanoparticles as foam stabilizer and pre–carbonated cement slurry

The stability of carbon dioxide (CO2) foam is critical for preparation and performance of CO2 foamed concrete (CFC). This study evaluated the effectiveness of nanoparticles for stabilizing CO2 foam and pre–carbonation of cement slurry for mitigating CO2 foam loss during CFC preparation, and conducted a comparative study of CO2 foam, pre-carbonized slurry and CFC, aiming at preparing CFC with excellent performance. The results demonstrated that the incorporation of nano–silica can significantly enhance the stability of CO2 foam, with an improved half–life and diameter distribution. The pre–carbonation process optimized consistency and alkalinity of cement slurry and increased the retention rate of CO2 foam after its introduction into cement slurry, thereby facilitating the production of low–density CFC. CFC exhibits high compressive strength and early internal temperature, and has a low water absorption. The presence of CO2 within pores and their subsequent formation of potential negative pressure via carbonation reaction contributed to a much lower thermal conductivity of CFC compared to air foamed concrete. Moreover, a thin layer of calcium carbonate was formed on the inner wall, which can densify the microstructure and modify the pores. Although the carbonation degree of CFC may be lower compared to that of conventional carbonation–cured foamed concrete, the internal and uniform carbonation within CFC greatly enhanced material strength. The non–destructive nuclear magnetic resonance results show that CFC has a more concentrated pore size distribution with fewer fine pores and a smaller pore throat radius.

A Prediction Model for Water Absorption in Sublayers Based on Stacking Ensemble Learning Method

A Prediction Model for Water Absorption in Sublayers Based on Stacking Ensemble Learning Method

Evaluation of the strength performance and microstructural properties of different based metakaolin blended cements containing greenly synthesized nanosilica

The drive towards improving the properties of cement composite thus making it eco-friendly, sustainable, and durable, has been the focus of the construction industry. Kaolin is one of the pozzolans that have been investigated in recent times, but its reactivity is influenced by its source. In addition, the problem of homogenous mixing onsite and early strength development of pozzolana blended cement are evident. This research focused on the strength and microstructural properties of factory-produced metakaolin blended cement incorporated with green nanosilica. Kaolin samples were obtained from three locations and calcinated at 700 ℃ for 1 h. Metakaolin was interground with 10% Portland Limestone Cement (PLC) clinker at the factory. Binder-sand ratio (1:3) with a water-binder ratio of 0.5 was adopted for batching the mortar. Nanosilica was added to the mortar at: 1, 2, 3, 4, and 5%, respectively. Prisms of 40 × 40 × 160 mm were cast and cured for 3, 7, 14, 28, 56, 90, 180, 270, and 365 days, respectively. The flexural and compressive strengths of prisms including the water absorption of cubes were evaluated. 10% MK addition enhanced the mechanical properties of the mortar with MK C having the highest enhancement. Incorporation of 1% nanosilica enhanced strengths at early and later ages, as well as refinement in the pores of the mortar with increasing nanosilica.

Study on the cementation and engineering properties of ternary eco-binder mortar containing pulverized coal fly ash mixed with circulating fluidized bed co-fired fly ash

This study aimed to verify the role and feasibility of co-fired fly ash (CFA) as an alternative construction material. It also demonstrated the engineering properties of CFA mortar and compared them with those of pulverized coal fly ash (PCFA) mortar. Further, CFA-PCFA-cement mortar specimens were mixed to produce ternary eco-binder mortars and find the optimal application proportion. The results pointed out that the pozzolanic strength activity index of CFA was 76%, with only a slight pozzolanic reaction. The sum of the chemical composition (SiO2+Al2O3+Fe2O3) of CFA was insufficient to meet ASTM C618 requirements, and it was deduced that a small amount of CFA should be used as the substitute for cement or fine aggregates. Specimens with CFA replacing fine aggregates contributed to lower water absorption, improved sulfate resistance, and increased compressive strength; Specimens with CFA replacing cement reduced shrinkage and improved sulfate resistance but decreased compressive strength and increased absorption. Blended CFA-cement mortars consisting of 5% CFA as a replacement material for cement and fine aggregates had excellent engineering properties. Ternary blended CFA-PCFA-cement mortar exhibits superior engineering properties. The optimum proportion is an economy-friendly binder composed of 10% CFA (5% as cement and 5% as fine aggregates) and 10% PCFA (as a replacement for cement).

Research on the application of phosphogypsum in magnesium oxysulfate cement: A comparison with sand

Phosphogypsum (PG), as an industrial by-product, has historically suffered from challenges in achieving efficient utilization, resulting in enormous accumulation and environmental contamination. In this study, a certain proportion of PG was employed as a substitute for sand in magnesium oxysulfate cement (MOSC). The effects of PG on the properties, pores distribution, phase composition and microstructure of MOSC were investigated. The results showed that the introduction of PG yielded several beneficial effects, including enhanced volume stability and water resistance, alongside reduced apparent density. However, it also entailed several drawbacks, such as decreased paste flowability, prolonged setting time and increased water absorption rate of the specimens. PG incorporation induced no new crystalline phase, but moderate PG could promote nucleation and development of 5Mg(OH)2∙MgSO4∙7H2O (5∙1∙7 phase) and the group at 10% PG substitution has the highest compressive strength of 68.2 MPa. PG demonstrated the capability to hinder precipitation of Mg(OH)2, thereby enhancing the mechanical properties of MOSC. Due to the affordability and favorable environmental sustainability, PG-MOSC displayed considerable potential for various applications. This study elucidates the mechanism by which PG influences MOSC, providing reference and approach for the recycling of PG.

Self-healing sulfonated poly(ether ether ketone)/polyvinyl alcohol membrane reinforced with sulfonated silica for direct methanol fuel cell

Nafion, the predominant choice for polymer electrolyte membranes (PEMs) in direct methanol fuel cells (DMFCs), excels in proton conductivity but is plagued by elevated methanol permeability and sustained performance degradation. To address these issues, this study aims to synthesize a self-healable composite membrane composed of sulfonated poly (ether ether ketone), polyvinyl alcohol, and sulfonated silica (S/PVA/S–SiO2). The composite membrane with 3 wt% S–SiO2 demonstrates the highest proton conductivity, thanks to its improved water absorption and increased proton transfer sites. Compared to pure SPEEK, the composite membrane has a 20% lower methanol permeability. With its enhanced selectivity, the S/PVA/S–SiO2 membrane produces a power density of 3.64 mW cm−2 at 26.67 mA cm−2. Furthermore, by virtue of reversible hydrogen bonding, the composite membrane shows exceptional self-healing capabilities, restoring its methanol-blocking function by 83.6%. These results highlight that the S/PVA/S–SiO2 membrane holds promise for DMFC applications.

Fabrication of sustainable, antioxidant, and antibacterial PVA nanomembranes loaded with plant extracts for dermal applications

Nanotechnology is unfolding its enormous abilities due to its unique attributes, such as large surface area, increased entrapment sites, and high surface energy. Similarly, nanotechnology-based products are replacing conventional ones due to their superior effectiveness. We have developed a dry, biocompatible, anti-oxidative, and antibacterial electrospun nanomembranes loaded with Cucumber (c. sativus) and Aloe vera (a.b miller) extract into polyvinyl alcohol (PVA) that can be utilized as dermal/skin patch. Various physiochemical characterizations are performed, such as scanning electron microscope (SEM), drug release, hydrophilicity, biocompatibility, antioxidant, and antibacterial activity on the developed membranes to ensure their productivity. Optimal nanofiber diameters were determined to be 396nm and 371nm at 8% wt./wt. and 100% extract concentration. The average particle size of extracts was 155 & 177nm, as determined by the Zeta sizer. The hydrophilicity of all developed nanomembranes is confirmed by having a water contact angle (WCA) of <60° and water absorption exceeding 550%. In addition, the nanomembranes exhibit burst drug release of > 72%, excellent biocompatibility, up to 92.8% cell viability, 86% anti-oxidative activity, and 99.8% effectiveness against Staphylococcus aureus (S. aureus) bacteria. Lastly, nanomembranes can withstand a tensile strength of 53.88N, an elongation of 1.72%, and an air permeability of 16.98mm/sec, making them an ideal choice for multipurpose cosmetic/skin patches.

The driving force of water absorption in cementitious materials: An analysis of surface-free energies and pore structure

The driving force of water absorption in cementitious materials: An analysis of surface-free energies and pore structure

Sustainable alternative activators from the textile mercerizing water for the durable and cost-effective flyash-GGBS based geopolymer concrete

By considering the current global challenges such as greenhouse gas emission and waste disposal management, the exploration of geopolymer concrete is highly focused now-a-days. On the other hand, the use of costlier commercial activators acted as the major drawback for the practical existence. Although the recent geopolymer researchers suggested the use of alternative activators from various resources such as palm oil ash, olive ash etc, the application of which are not appreciably promoted due to the complex derivation process. To overcome these effects, in this paper, first time, an attempt is initiated to develop a cost-effective geopolymer concrete by using textile mercerizing water as an alternate activator system. The viability of using mercerizing water instead of commercial sodium hydroxide activator was studied initially. By conducting the pH electrode test and Infrared Analysis, the alkalinity and the presence of sodium metal cations responsible for the reaction kinematics were confirmed. Also, the molar concentration of sodium cations in the mercerizing water was quantified using chemical titration analysis. The feasibility of using mercerizing water in the preparation of geopolymer was assessed using workability, mechanical strength and sustainability. From the results, it was inferred that the developed geopolymer concrete with 100 % textile mercerizing water exhibited the maximum strength of 46.9 MPa, 5.16 MPa and 5.81 MPa respectively under compression, tension and flexure which are almost equivalent and slightly better than the control geopolymer concrete. Also, the developed geopolymer concrete using 100 % textile mercerizing water and the combined flyash-GGBS binder system showcases the highest post-fire residual strength and 48 % reduced water absorption. The cost of construction of geopolymer concrete was significantly reduced by 58.43 % and showed 10.28 % reduced carbon footprint due to the complete replacement of sodium hydroxide solution using textile mercerizing water. The findings of this research work will lead to the development of equivalent molar sustainable activator from the textile mercerizing water and the exploration of eco-friendly and durable geopolymer concrete in an affordable price.