Super Absorbent Research Articles

Effects of Polyacrylamide-Based Super Absorbent Polymer and Corn Straw Biochar on the Arid and Semi-Arid Salinized Soil

Green approaches are much more appreciable during the present scenario. Soil amendments are frequently applied for improving water use efficiency, reducing soil salinity in arid and semi-arid areas, controlling the secondary salinization of cultivated soils, and increasing the carbon sequestration capacity of soils. Thus, lab soil column simulation experiments and field experiments were carried out to evaluate these functions of two separate amendments, polyacrylamide-based super absorbent polymer (SAP) and corn straw biochar at different application rates. The simulation experiments showed that both SAP and biochar inhibited the accumulation of soil salinity, with a reduced rate of 9.7–26.3% and 13.5–37.2%, respectively, dependent on the amendment application rates. The field experiments found different salt inhibition effects of the two amendments with growth stages of maize. Soil salinization was inhibited in the pre-germination and early jointing stages by SAP, but throughout the whole growth period by biochar. Both soil amendments reduced soil electrical conductivity, and biochar increased the soil contents of Ca2+, Mg2+, and K+. Our observations demonstrated that application of biochar and SAP played important roles in increasing soil fertility and inhibiting soil salt accumulation. It provided an effective method to potentially mitigate the environmental crisis and promote sustainable development in agriculture.

Effect of Internal Curing Agents in Self Compacting Concrete

The scarcity of water is the biggest challenge to India. More amount of water is utilized in construction industries for concrete curing. Steps were taken concentrating in reducing water used for curing. Controlling and monitoring the amount of water in concrete is important for both constructability and service life as the amount of water in concrete controls the properties of concrete. In this project various Internal Curing Agents (ICA) like Super Absorbent Polymer (SAP), Poly Ethylene Glycol (PEG) and water-saturated lightweight aggregate (LWA) are used in Self compacting concrete (SCC) to investigate its influence in gaining strength to reach the target strength of M40. All these materials work in similar manner that they act as a reservoir, hold water and desorbs the readily available water throughout concrete to continue the hydration process. In this paper all the three ICAs are added individually in concrete and its influence on strength is studied. SAP performs well compared to all other internal curing materials on workability aspect. The workability properties like Slump flow, L Box and V Funnel tests were conducted and all the test results satisfies the standards of EFNARC Codal provision. The effect of different dosages of ICAs in concrete leads to variation in strength parameters. ICAs in concrete mixes can be successfully used concrete structures.

Experimental study on improving the strength of concrete by using self-curing technic with Poly ethylene glycol and super absorbent polymer

Increase in infrastructural projects demands the need for workable concrete in the 21st century. With the technological advancement there is a need for looking into an alternate solution to the current day problems in the construction sector. Shortage of water is also a concern in some of the places which demands for the utilization of a better substitute to water in concrete. Internal curing agents like Polyethylene Glycol (PEG400), ceramic and Super Absorbent Polymer are used extensively which would be beneficial for engineering and construction applications. Day by day increasing of waste from disposable diapers will give increase the waste generation and requires large space dumping. To overcome this diapers which are primarily worn by infants, and by children who are not yet potty trained or who experience bedwetting are used in the present study as a self-curing agent along with PEG 400. In this present study, influence of PEG and diaper polymer on the workability and compressive strength of the concrete was investigated. M40 grade of concrete has been adopted for the entire study. Compressive strength at 3, 7, 28 and 90 days was calculated for 150mm X 150mm X150mm cubes with the 1%PEG as a control mix and 1% PEG + varying ratios of 1% to 10% of diaper polymer with 5% interval. It was observed that workability increased with the addition of diaper polymer and the strength decreased.

Mechanical and Thermal Performance of Cement Mortar Incorporating Super Absorbent Polymer (SAP)

Super Absorbent Polymer (SAP) is a favorable admixture which can influence various properties of cementitious materials. It mainly improves the water retaining properties of cement-based construction materials. In this paper, an experimental program was carried out to determine the mechanical and thermal performance of cement plaster containing SAP. Firstly, the absorption capacity of SAP was determined in different loading conditions and chloride solutions. Thereafter, the optimum dosage of SAP for cement plaster was also determined from five different proportions of SAP (0.05, 0.1, 0.3, 0.5 and 1% of cement mass) based on the compressive strength test results. The mortar incorporating 0.05% SAP of cement mass was selected as the optimum dosage, which yielded the highest compressive strength. Two slabs of 1×1×25 mm with 0.05% SAP and two slabs of 1×1×25 mm without SAP were cast to determine the thermal performance of the cement mortar with and without SAP. For this purpose, a wooden chamber of 2×1×1 m was constructed and the slab was placed in the middle of this chamber to carry out the thermal performance test of cement mortar. The slabs with 0.05% SAP showed promising results for acting as a thermal barrier in buildings compared to slabs without SAP. Doi: 10.28991/cej-2020-03091614 Full Text: PDF

Experimental Study on Self Compacting Concrete Withaddition of Super Absorbent Polymer

This experimental work focuses on the effect of superabsorbent polymer (SAP) in self-compacting concrete (SCC). The target strength to be achieved is M40. The superabsorbent polymer acts as an Internal curing agent (ICA) which is added at a percentage varying from 0.1 to 0.3 and superplasticizer to about 0.8% with respect to the mass of cementitious materials. SCC is super workable due to its low water-cement ratio, which gives rapid strength, more durability, and best quality. In this study the properties of fresh and hardened concrete were investigated. The workability properties like Slump flow, V Funnel and L Box tests were carried out. The mechanical behaviour and durability study such as Rapid Chloride Penetration Test (RCPT) were alsoconducted on SAP added SCC. SEM Analysis was carried out toidentify the newly formed materials within the concrete system. The concrete added SAP behaves similarly and as like the conventional concrete in strength aspect but varies in case of durability properties.

고흡수성 폴리머와 나노셀룰로오스 배합비에 따른 스파티필럼의 생육 반응

This study was conducted to investigate the value of Cellulose Nanofiber (CNF) as replacement material of Super Absorbent Polymer (SAP). When the mixing ratio of SAP and CNF was 2%, the green coverage rate, chlorophyll fluorescence was the best, and Leaf water contents were the highest, and electrolyte leakage was the lowest, showing relatively high growth response. Spathiphyllum had the longest life and maintained a good growth condition with CNF 2% mixing ratio comparing with others under water stress. In addition, the water stress caused by the moisture content is relatively low, so the chlorophyll fluorescence and Leaf water contents were high, and electrolyte leakage is low. As a result, the use of CNF as a high-absorbent polymer substitute is well worth in urban environments, which can be used as a functional material to save maintenance costs and respond to climate change such as drought.

Biodegradable superabsorbent with potential biomedical application as drug delivery system of “pectin-g-P(AN-co-AM)/chicken eggshell” bio-composite

The outer cover of the egg (chicken) having the mesh size in the range of 100–350 μm serves as a versatile bio-filler for manufacturing of a novel biocomposite, “pectin-g-P(AN-co-AM)/chicken eggshell”, which was synthesized by using water-soluble cobalt complex as effective catalyst, and its properties were studied by using FTIR and on–off switching swelling behaviour. Moreover, water absorbency and biodegradability along with drug delivery properties of the prepared material were studied by using proper methods. It was observed that the synthesized material shows property of super absorbency (hydrogel) and demonstrates interesting results at pH = 2 and 8 and is responsive to swelling-de-swelling behaviour. This novel material also shows potential applications in drug delivery system. This bio-composite is cost-effective and environmental friendly because it is synthesized in microwave-assisted medium without emission of any toxic gaseous components to the atmosphere.

Combined compression-shear performance and failure criteria of internally cured concrete with super absorbent polymer

The aim of this study was to explore the mechanical properties of internally cured concrete with Super Absorbent Polymer (SAP). We studied the composite compression-shear properties of the concrete with varied water-cement ratios under different axial pressures. The compressive, splitting-tensile, and composite compression-shear mechanical properties of concrete examples were characterized by making SAP concrete (SAPC) specimens with different water-cement ratios. The failure modes of the concrete were compared and analyzed, and the load–displacement curves of SAPC under different axial pressures were obtained. The relationship between compression-shear strength, residual strength, and axial pressure was studied by analyzing the characteristic value of load–displacement curves. The results showed that the compression-shear strength and residual strength of SAPC increased linearly with the axial pressure, while the friction coefficient of compression-shear strength and cohesive stresses decreased with the increase of SAP content. By analyzing the compression-shear strength of SAPC, the failure criteria based on the octahedral stress space and twin-shear strength theory were established. The proposed failure criteria were verified by using experimental results of other concretes in literature. The verification results confirmed that the proposed failure criteria were efficient and beneficial for engineering applications of SAPC.

Super Moisture Absorbent Gels for Sustainable Agriculture via Atmospheric Water Irrigation

An atmospheric water irrigation system based on super moisture absorbent gels (SMAG) is developed for sustainable agriculture technology. The SMAG-soil can harvest water from the air and provide wa...

Effect of Internal Curing by Super Absorbent Polymer on the Autogenous Shrinkage of Alkali-Activated Slag Mortars.

Alkali activated slag (AAS) mortar is becoming an increasingly popular green building material because of its excellent engineering properties and low CO2 emissions, promising to replace ordinary Portland cement (OPC) mortar. However, AAS’s high shrinkage and short setting time are the important reasons to limit its wide application in engineering. This paper was conducted to investigate the effect of internal curing(IC) by super absorbent polymer (SAP) on the autogenous shrinkage of AAS mortars. For this, an experimental study was carried out to evaluate the effect of SAP dosage on the setting time, autogenous shrinkage, compressive strength, microstructure, and pore structure. The SAP were incorporated at different dosage of 0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 percent by weight of slag. The workability, physical (porosity), mechanical, and shrinkage properties of the mortars were evaluated, and a complementary study on microstructure was made. The results indicated that the setting time increased with an increase of SAP dosage due to the additional activator released by SAP. Autogenous shrinkage decreased with an increase of SAP dosage, and was mitigated completely when the dosage of SAP ≥ 0.2% wt of slag. Although IC by means of SAP reduced the compressive strength, this reduction (23% at 56 days for 0.2% SAP) was acceptable given the important role that it played on mitigating autogenous shrinkage. In the research, the 0.2% SAP dosage was the optimal content. The results can provide data and basis for practical application of AAS mortar.

Experimental investigations on early-age tensile creep of internally cured high strength concrete under different initial stress/strength ratios

High strength concrete (HSC) with high strength and low permeability has been widely utilized in the reinforced concrete structures recently. However, the water-to-cement ratio of HSC is low, marked self-desiccation will occur, and autogenous shrinkage is induced. The autogenous shrinkage causes tensile stress in the restrained concrete, and the tensile creep (TC) counteracts the autogenous shrinkage as a stress relaxation mechanism. Although the TC of internally cured HSC (ICHSC) with super absorbent polymers (SAPs) under fully restrained conditions has been studied, research on the early-age TC of ICHSC under constant tensile loading remains insufficient. Therefore, the effect of initial stress/strength (s/s) ratio (ranged from 20% to 35%, 50%, and 65%) on the TC behavior of ICHSC at early age was experimentally investigated by Temperature Stress Test Machine in this research. Experimental results and corresponding analysis showed that: (1) the early-age basic TC, basic TC coefficient, and specific basic TC of ICHSC at 7 days of loading was 37, 66, 95, and 148 με, 2.26, 2.31, 2.30, and 2.76, and 52, 53, 53, and 72 με/MPa, respectively, and increased as the initial s/s ratio increased; (2) the early-age basic TC rate of ICHSC at 1 day of loading was 0.57, 1.01, 1.70, and 3.04 με/h and increased as the initial s/s ratio increased; (3) the nonlinear basic TC of ICHSC occurred when the initial s/s ratio ranged from 50% to 65%; (4) a prediction model for the TC of ICHSC considering initial s/s ratios was proposed based on Østergaard model.

Biochar, manure, and super absorbent increased wheat yields and salt redistribution in a saline‐sodic soil

AbstractSalinity and sodicity problems are ubiquitous in dryland and irrigated systems, and research into possible amendments to remediate soils in these systems is needed. This study was conducted to investigate the effects of organic and inorganic amendments on spring wheat (Triticum aestivum UG99) yield and salts redistribution within the profile of a repacked saline–sodic silt loam soil (ECe = 12.9 dS m−1, exchangeable sodium percent (ESP) = 17.6% for control). The experimental design for greenhouse study was completely random with two factors (amendment and leaching fraction, LF). The amendments included biochar (2%) [B], biochar + manure (2%) [BM], zeolite modified with CaCl2 (2%) [ZC], super absorbent (1%) [SA], and a control (no amendment) considering two levels of LF (15 and 30%). All amendments, except ZC, decreased soil bulk density and electrical conductivity, and increased soil pH and water content at field capacity after 2 pore volumes leaching. There was positive effect (p < .001) of B, BM and SA on wheat ground cover and grain yield; ZC amendment had no effect on wheat growth or yield. The LF levels did not affect wheat growth or yield. The amendments (B, BM and SA) decreased Na+ and Mg2+ concentration in straw, while K+ concentration increased; resulting in reductions in the Na+/K+ ratio. In general, the study showed that B, BM and SA are suitable amendments for increasing yield by improving soil conditions and reducing salts and Na+ accumulation in plants.

The development of a rapid and reliable method (SAPSWash): For the extraction and recovery of spermatozoa from superabsorbent polymer containing products

This work presents a rapid and reliable method to recover spermatozoa from Super Absorbent Polymers (SAPs) commonly found in sanitary protection products such as nappies and sanitary towels. The use of salt solutions was investigated and a protocol was developed using a calcium chloride (CaCl2) solution to release semen deposited onto a selected SAP containing product. The method was tested on ultra-sanitary towel samples treated with a known amount of semen. A range of treatments were examined; some samples were prepared and immediately frozen for storage and others were allowed to air dry overnight to replicate the condition of similar items recovered for examination in sexual offence cases. The method allowed the collection of low yields of spermatozoa, but these were still sufficient for microscopic identification of intact heads and to obtain ESI17 DNA profiles from all the samples. This report presents the method, the results obtained and discusses prospective adaptations to the method for validation to implement the method into forensic casework.

Multimodal Reduction of Elastic Vibrations in Plate Structure using Super Absorbent Polymer Beads

This paper deals with multimodal reduction of structural elastic vibrations. Super absorbent polymer beads (SAP beads) have been introduced as a simple damping device inspired by the multimodal vibration reduction effect by passengers on railway vehicles. A series of vibration measurement tests using a 1:10 scale model of railway vehicle floor structure (model underframe) was carried out. The SAP beads which are sold commonly as water retention agent were stacked in a container and applied to the model underframe. From the experiments, multimodal vibration reduction effects have been demonstrated. A drastic difference has been observed when water was added together with SAP beads. To investigate the basic mechanism of the damping effect obtained by the experiments, an analytical model, which consists of multiple masses that are supported at an angle to each other, and its simplified model was proposed and numerical studies were conducted. Some specific combinations of the mass, spring, and damping elements in the model could express the experimental results well, and it has been estimated from the numerical results that each SAP layer act as an un-uniform subsystem.

Influence of super absorbent polymers on early-age behavior and tensile creep of internal curing high strength concrete

High strength concrete (HSC) possessing high strength and excellent durability has been widely put into use in the reinforced concrete structures. However, a low water-to-cement (w/c) ratio is usually utilized for HSC, which may increase the autogenous shrinkage due to self-desiccation, and then decrease the cracking resistance of HSC. Internal curing (IC) with super absorbent polymers (SAPs) is utilized to mitigate the autogenous shrinkage and improve the cracking resistance of HSC. Although cracking resistance and tensile creep of IC concrete utilizing SAPs under axial or circumferential restrained conditions have been investigated, research on tensile creep of IC HSC (ICHSC) utilizing SAPs under a constant initial stress to strength (s/s) ratio at early age remains insufficient. Accordingly, the early-age behavior and tensile creep of ICHSC utilizing different SAPs contents (0%, 0.57%, 0.86%, and 1.14% of the cement by weight) under a constant initial s/s ratio were experimentally investigated by the Temperature Stress Test Machine in this research. Test results and related analysis showed that: (1) the mechanical properties of ICHSC with the same basic w/c ratio decreased as SAPs content increased; (2) the autogenous shrinkage of ICHSC decreased as SAPs content increased; (3) the basic tensile creep, basic tensile creep coefficient, and specific tensile creep of ICHSC increased nonlinearly as SAPs content increased, which was due to the increase of total w/c ratio.

Effect of A200 super absorbent polymers on corn growth and yield under Partial Root-Zone Drying Irrigation

Water crisis: One of the most important and effective solutions to cope with water crisis is optimum use of consuming water in agriculture section. In other word, increasing “agricultural water productivity” is unavoidable in future planning and decision making as an effective factor. Therefore, deficit irrigation is stated as a proper solution in water limitation aiming to maximally use water volume unit. In addition to applying irrigation management methods, using developed techniques to save soil moisture is of the effective measures to increase irrigation efficiency and achieving sustainable agriculture. One of the strategies for optimal use of water resources and its preservation is using super absorbent polymers. This study was conducted during two growth seasons and within 2014-2015 in the farm and in Sari University of agricultural sciences and natural resources on single cross 704silage maize. The treatments included three irrigation regimes (as the main plot) and three levels of super absorbent (as subplots) with three replications. Irrigation treatments included complete and partial root irrigation in two levels of 55 and 65% (PRD65, PRD55) and three levels of water super absorbent polymer of A200 type, including 20, 40 and 60kg/hectare. Based on the obtained results, the plants, were regularly irrigated during their growth period and cultivated in the conditions of 60kg/hectare of super absorbent, had the most rate of yield components but they weren’t significantly different from those plants, irrigated with 55 and 65% volume. In other word, the function of super absorbent in these treatments increased the efficiency of water use and partial irrigation in 55 and 65% volume has been able to generate an equal yield with the conditions of complete irrigation.

Esterified Polysaccharide Composites that Display Super Absorbency from Highly Favorable Hydrogen and Ionic Interactions

The aim of the current research is to develop super absorbent materials from wood-pulp-based materials for the replacement of petroleum-based super absorbent hygienic products. The effect of citric...

Influence of Barchip fiber on early-age autogenous shrinkage of high-strength concrete internally cured with super absorbent polymers

High-strength concrete (HSC) usually suffers the high early-age autogenous shrinkage owing to the low water-binder (w/b) ratio. Barchip fiber and super absorbent polymers (SAPs) have been utilized to reduce the autogenous shrinkage of HSC at early age. The relationship between autogenous shrinkage and ultrasonic velocity of internally cured high-strength concrete (ICC) reinforced with Barchip fiber was studied utilizing the non-contact shrinkage test. Experimental study and corresponding analysis demonstrated that: (1) the autogenous shrinkage and ultrasonic velocity of concrete decreased with the volume percentage of Barchip fiber increasing, and decreased with the addition of SAPs; (2) models for predicting early-age autogenous shrinkage strain and ultrasonic velocity of ICC reinforced with Barchip fiber considering the fiber volume percentage and age were proposed; (3) the model of early-age autogenous shrinkage strain based on the results of ultrasonic velocity at different ages and at 28 d with no addition of Barchip fiber was proposed; (4) the prediction model of early-age autogenous shrinkage strain of ICC reinforced with Barchip fiber based on the age-dependent parameter on ultrasonic velocity was proposed.

Study on the optimization of the performance of preformed particle gel (PPG) on the isolation of high permeable zone

Unwanted water production is a critical problem in fractured reservoirs. Corrosion of facilities and reduction of oil relative permeability are some of the consequences of high water production. Preformed particle gel (PPG) injection is one of the conformance control methods, which initiated in 2007, has been used to control water production and increase sweep efficiency. There are several parameters which affect the performance of PPG such as stability at reservoir condition, salinity of makeup solution and PPG particle size and concentration. Although the study of the application of PPG in fracture plugging attracted a lot of attention in recent years, there are limited studies to investigate the effect of PPG physical properties on its application in water production control. In this study, the application of a super absorbent polymer on fracture plugging has been investigated. The results of swelling tests indicated that this type of PPG had significant high resistance even at high temperatures and wide range of salinities. In addition, the results of rheology tests showed that the PPG solution was stable even at high salinity and high shear rate condition. In order to study the mechanism of improvement of sweep efficiency through PPG injection, visual investigation using glass etched micromodel was performed. The results showed that the main mechanism for PPG treatment is water diversion into the low permeability zone as the consequence of fracture plugging. Also, core flooding tests were performed to check the performance of PPG in a heterogeneous carbonate porous media. According to the results, PPG was able to reduce the permeability, and this permeability reduction is related to swelling ratio which is controlled by makeup solution salinity. The results of this study revealed the potential of super absorbent polymers as preformed particle gel in unwanted water production through fracture plugging.

Effects of Super Absorbent Polymers and Gibberellin on Germination and Growth of alfalfa

For proven effects of eco-friendly super absorbent polymer and gibberellin on germination and growth of alfalfa, taking the germination and growth test in the artificial climate box by adding the different amount of super absorbent polymer and gibberellin. Observed the germination potential, germination rate, shoot length, root length, fresh weight and dry weight, under the different experiment conditions. The test showed that the super absorbent polymer had a promoting effect on alfalfa. The property of slowly release water, water supply on super absorbent polymer could keep plants prolonging the survival rate in the case of insufficient water supply. It could improve the germination rate of the seed of alfalfa. Adding super absorbent polymer and gibberellin not only improved the survival rate, but also promoted the growth of root and shoot on alfalfa.