Absorbent Polymer Research Articles

Superabsorbent polymer with improved permeability and absorption rate using hollow glass microspheres

AbstractItaconic acid‐vinyl sulfonic acid based super absorbent polymer (SAP) was synthesized by aqueous solution polymerization using ammonium persulfate as the initiator, tetra (ethylene glycol) diacrylate as the internal crosslinking agent, and sodium hydroxide as the neutralizing agent. Surface‐crosslinking was introduced to improve the low absorbency under load of the itaconic acid‐based SAP. Hollow glass microspheres were added during surface‐crosslinking to improve the absorption properties and permeability of the SAP. Hollow glass microspheres increased the specific surface area of SAP and acted as an incompressible filler resulting in the improvement of gel strength and the relief of gel blocking by preventing adhesion between SAP particles. The surface‐crosslinked SAP with 2 wt% hollow glass microspheres showed the highest permeability and absorbency under load. The absorption rate of the synthesized material was also increased.

Effect of calcined bauxite powder or aggregate on the shrinkage properties of UHPC

Commonly used internal curing (IC) agents (super absorbent polymers or lightweight aggregate) to mitigate the higher levels of autogenous shrinkage in UHPC could possibly lead to a negative effect on the mechanical properties of concrete due to the increased void created by the agents, the not-well estimated added water for IC, or low strength of the materials. In this study, a new type of calcined bauxite (CB) aggregate was found to be stronger than normal aggregate and exhibit a porous structure. Different quantities of this aggregate and its powder product were applied to estimate their effect on the mechanical and shrinkage properties of non-fibrous UHPC matrixes and UHPCs with steel fibers. The maintained higher internal relative humidity and significantly reduced autogenous shrinkage (more than 65%) demonstrate that the use of either dry or prewetted CB aggregate can both provide IC effect in UHPC. It reveals that the dry CB aggregate absorbs water during mixing and releases them after setting. Both the compressive and tensile strength of UHPC mixtures were significantly improved by using CB aggregate as compared to the reference mixture, which is due to the actual lower effective w/b, enhanced properties of the ITZ, and increased hydration by internal curing. However, the powder product of CB did not provide IC effect, but a higher content of CB powder (600 kg/m3) helped enhance the strength of UHPC matrix while the one with 300 kg/m3 of CB powder obtained similar strength both compared to the reference mixture.

Temperature and Ph-sensıtıve Super absorbent Polymers based on Modıfıed Maleıc Anhydrıde

Maleic anhydride was modified with 1-decanol at two different ratios to obtain derivatives named MD-75 (75% modified) and MD-100 (100% modified). By using these derivatives and acrylamide (AAm), many hydrogels with different AAm/MD ratios were synthesized. Ammonium persulphate (APS), N,N,N′,N′-tetramethyl ethylenediamine (TMEDA) and N,N′-methylene bisacrylamide (MBAAm) were used as initiator, catalyts and crosslinker agent respectively in the synthesis reaction. The modification reactions were clarified by FTIR and 1H-NMR methods. Swelling behaviours, swelling capacities and effect of temperature, pH of the swelling medium and hydrogel composition on these parameters were studied. The swelling capacity of the hydrogels increased up to 82700% with decreasing the AAm/MD ratio. Temperature and pH of the swelling medium and the composition of the hydrogels were found to have a strong effect on the swelling behaviour and the swelling capacity of the hydrogels. The gels showed low swelling capacity with single-step swelling behaviour at low temperatures (T≤50 °C) and high swelling capacity with two-step swelling behaviour at higher temperatures. The swelling and diffusion kinetics of the hydrogels were also determined. All of the synthesized hydrogels showed uniform diffusion type at low temperatures while two types of diffusion observed at high temperatures. Hydrogels of modified maleic anhydride were prepared by chemical cross-linking. Hydrogels showed excellent swelling capacity up to 82,700%. Temperature and pH have a strong effect on the swelling capacity of the hydrogels. Hydrogels showed two-step swelling behaviour.

Application of Super Absorbent Polymer in the Research of Water-retaining and Slow-release Fertilizer

Super absorbent polymer is a new type of functional polymer material that has been researched in recent decades. Due to its special structure and water-absorbing and water-retaining properties, it has a broad field of drought resistance, soil improvement and crop protection. It is a new type of soil conditioner and agricultural drought-resistant and water-saving materials. Combining it with fertilizers to prepare agricultural and forestry slow-release fertilizers with water-absorbing and water-retaining functions, it is very good in improving fertilizer utilization and saving water resources. This article summarizes the literature, expounds the research status, existing problems, and future research directions and hot spots of super absorbent resins.

Evaluation of optimum dosage in blended self curing concrete on the impact of supplementary cementitious materials (scm’s) and durability studies on different proportions

Now a days, the shortage of potable water increases, for domestic and commercial purposes due to environmental conditions. Due to this scarcity, curing of concrete is affected and in this point of view water assets are more valuable every day and becomes more economical. Traditional Curing used for retaining moisture within the concrete elements during the early days and beyond to develop the desired properties in terms of strength & durability. To develop the modern era curing, a few of self-curing agents like Super Absorbent Polymers, Polyethylene Glycol (PEG 400) has been used for internal curing of concrete used for reducing the hydration process. In this experimental study, Supplementary Cementitious Materials like Class F Flyash, Silica Fume and Ground Granulated Blast Furnace Slag (GGBFS), have been casted for 65%+25%+15% (M2), 65%+20%+15% (M6), 65%+25%+10% (M10) and 65%+20%+15% (M11) of optimal mix proportions. The sorptivity assessments have being carried out on all blended mixes of Self Cured Concrete with size of 15 cm x 15cm x15cm. The pH value of the acidic medium was at 0.45 by submerging in acid, the specimen samples are brought out and were cleaned in repeatedly with water and kept in atmospheric condition for two days for constant weight and then the specimens are balanced using weighing scale and loss in weight and hence the percentage in loss of weight was premeditated within and after 28 days with different mix proportion of M30 grade of concrete supplementary cementitious materials like Flyash, Ground Granulated Blast Furnace Slag and Silica Fume with PEG 400 as 1% by its weight.

Single-step equipment-free extracellular vesicle concentration using super absorbent polymer beads.

Extracellular vesicles (EVs) contain useful biomarkers for disease diagnosis and are promising biomaterials for the delivery of therapeutic molecules in vivo. Accordingly, an efficient concentration method is necessary for large‐scale production or high‐throughput isolation of EVs from bulk liquid samples, including culture medium and body fluids, to achieve their clinical application. However, current EV concentration methods, including ultrafiltration, are limited with respect to cost, efficiency, and centrifugation time. In this study, we developed the first single‐step, equipment‐free EV concentration method using super absorbent polymer (SAP) beads. SAP beads absorb small molecules, including water, via nano‐sized channels but expel and thereby concentrate EVs. Consequently, the beads drastically enrich EVs by reducing the solution volume in a single step, without affecting EV characteristics. Moreover, the purity of the concentrated EV solution was high due to the absorption of protein impurities by SAP beads. To further demonstrate the versatility of the method, we showed that SAP beads successfully enrich EVs in human urine samples and culture medium, enabling better isolation performance than conventional ultrafiltration. We believe the newly developed approach and insight gained in this study will facilitate the use of EVs as prominent biomaterials for disease diagnosis and therapy.

Mechanistic study of the wettability alteration induced by preformed particle gel (PPG) in carbonate reservoirs

Excess water production is one of thechallenges through oil production, especially in fractured reservoirs. Application of Preformed Particle Gel (PPG) to control the excess water production attracts attention in these years. The effect of the wettability of the reservoir rock on the performance of PPG by water shutoff in fractured reservoirs is not well understood. This research aims to investigate the effect of wettability on the performance of PPG through contact angle analysis, fluid flow in micromodel, and simulation using UTGEL. The PPG which is used in this study is a super absorbent polymer. According to TGA analysis, this PPG is stable at reservoir temperature. Contact angle measurement results for both sandstone and carbonated thin sections revealed that PPG can alter the wettability of the oil wet thin sections. The wettability alteration is higher in carbonate rock (64% toward to water wetness) rather than sandstone (50% toward water wetness) which could be related to the surface charge of the carbonate rock. Also, the wettability alteration in sandstone sample induced by PPG could be related to the presence of the clay. In order to evaluate the effect of wettability on PPG performance in porous media, flooding tests were carried out in both water wet and oil wet micromodels. The injection sequences were waterflooding, PPG injection and secondary waterflooding in both water wet and oil wet micromodels. The results show that the oil recovery factor in the first waterflooding is higher for the case of water wet micromodel. This is because water can flow much easier in water wet condition rather than oil wet state. After PPG injection, the oil recovery factor was higher in oil wet micromodel. This could be described as a change in wettability caused by PPG in oil wet conditions. Therefore, the findings of the wettability alteration in oil wet micromodel were consistent with those obtained by contact angle measurements. The ultimate recovery factor was almost identical in both water wet and oil wet conditions. According to visual observation, PPG tends to flow into the pores filled by water because of the chemical structure of PPG that only absorbs water. In order to validate the experimental results, PPG flow in a fractured porous media with characteristics similar to micromodel was simulated by UTGEL. The simulation model was validated by micromodel measurement data including the oil recovery factor, waterfront, and water-oil ratio. The results of this study reveal that the wettability alteration is one of the mechanisms through water shutoff by PPG in oil wet fractured reservoirs.

Performance characterization of γ-poly (glutamic acid) super absorbent polymer and its effect on soil water availability

ABSTRACT A novel biodegradable super absorbent polymer (SAP) was synthesized by γ-poly (glutamic acid) (γ-PGA) and poly (ethylene glycol) with the units of glycidyl ether as chain ends (PEGGE). The resultant γ-PGA SAPs with different PEGGE contents were characterized and their effects on soil total available water (TAW) were investigated. The γ-PGA SAP was synthesized at 45 °C for 48 h when γ-PGA was 160 g L−1 (pH = 4.9) and the minimum mass of PEGGE was 20% of the γ-PGA mass. When the PEGGE increased from 20% to 60%, the water absorption rate (WAR) of γ-PGA SAP in distilled water and 0.9% NaCl solution gradually decreased from 651.16 g g−1 to 302.91 g g−1 and from 44.83 g g−1 to 32.9 g g−1 respectively. The γ-PGA SAP with 40% PEGGE had the highest WAR after being reused six times. The field water capacity (FC) and TAW increased with the increasing γ-PGA SAP content; however, when the same amount of γ-PGA SAP was added to the soil, the FC and TAW in the soil gradually decreased with the increasing PEGGE in the γ-PGA SAP. The γ-PGA SAP with a proportion of 0.15% in the soil presented the largest soil WAR.

Effects of poly-γ-glutamic acid and poly-γ-glutamic acid super absorbent polymer on the sandy loam soil hydro-physical properties.

The main forms of poly-γ-glutamic acid (γ-PGA) applied in agriculture include agricultural γ-PGA and γ-PGA super absorbent polymer (SAP). Laboratory experiments were conducted with a check treatment CK (no γ-PGA added) and two different forms of γ-PGA added to sandy loam soil (T and TM stand for γ-PGA and γ-PGA SAP) at four different soil mass ratios (0.05% (1), 0.10% (2), 0.15% (3) and 0.20% (4)) to determine their effects on sandy loam soil hydro-physical properties. Both of them could reduce the cumulative infiltration of soil water. The total available water (TAW) which the soil water content (SWC) from field water capacity (FC) to permanent wilting point (PWP) after γ-PGA added into sandy loam soil had no significant different compared with CK, and the TAW was highest at the treatment of γ-PGA with 0.10% addition amount into sandy loam soil. However, the TAW of sandy loam soil increased dramatically with the γ-PGA SAP addition amount increasing. TM3 had the highest soil water absorption among the treatments with γ-PGA SAP. The T1 to T4 treatments with γ-PGA addition slightly prolonged retention time (RT) when SWC varied from FC to PWP compared with CK. For γ-PGA SAP addition treatments, the time for SWC varied from FC to PWP was 1.48 times (TM1), 1.88 times (TM2), 2.01 times (TM3) and 2.87 times (TM4) longer than that of CK, respectively. The results of this study will provide further information for the use of these materials in agricultural application.

Development of self-stressing Engineered Cementitious Composites (ECC)

While high ductility Engineered Cementitious Composites (ECC) have demonstrated effectiveness for infrastructure repair, the microcracking induced by the high material shrinkage may decrease the structural durability of ECC in aggressive environments. The objective of this research is to develop a self-stressing ECC, the expansion of which against the restraint of the repaired structure automatically induces pressure onto the repair material. Super absorbent polymer (SAP), shrinkage reducing agent (SRA), and calcium sulphoaluminate cement/expansive additive (CSA) were utilized together with Portland cement to tailor the composite expansion and expansive pressure. Free drying expansion/shrinkage, restrained expansive stress, and tensile performance were examined through standard shrinkage measurement, steel ring restrain test, and uniaxial tensile test, respectively. It was found that the 28 days drying shrinkage was decreased by 47% due to the use of SRA but was slightly increased when SAP was used. Substituting 42% of OPC with CSA (K42) increased ECC strength and ductility. The K42-ECC experienced a maximum expansion of 3756 με at 3 days and retained 2026 με expansion at 28 days. However, the expansion loss between 3 days and 28 days counteracted the expansive pressure. The deliberate combination of SRA and CSA provides a self-stressing effect tailoring the maximum expansion and expansion loss. The self-stressing performance along with a 7% ultra-high strain capacity and average crack width of 35–44 μm at 3% strain promotes the developed ECC as a more durable material for infrastructure repair.

Evaluation of sand-clay-anionic polyacrylamide blends for alternative compacted clay landfill liner design

In this project, an innovative low hydraulic conductivity material for landfill cover and liner construction was studied. The material is a blend of natural clayey soil from Comodoro Rivadavia city (Chubut province, Argentina) mixed with fine uniform sand and anionic polyacrylamide (APAM). The research emphasizes understanding the influence of APAM addition on the soil water retention capacity (SWRC), unsaturated hydraulic conductivity, and swelling behavior. APAM is a super absorbent polymer that swells when immersed in water. SWRC was evaluated through the filter paper method. The unsaturated hydraulic conductivity and swelling behavior were determined using two fluids: distilled water and brine (C = 2 M). Results showed that APAM addition reduced the blends' microporosity, increased the water retention capacity, and reduced the hydraulic conductivity of the system. These promising results encourage further research on these blends' behavior to determine the most efficient blend formulation to enhance its hydro-mechanical performance and its chemical compatibility with landfill leachates for cover and low hydraulic conductivity liner layer construction.

DEM modelling of swelling of grains

Swelling of grains due to water absorption is ubiquitous in many natural materials and industrial products. Hence, a thorough understanding of grain swelling is of great scientific importance. An experimental investigation can only provide limited information, whereas great insight could be gained from numerical modelling, rigorous numerical models for describing particle swelling are essential. Thus, the objective of this study is to develop and validate a discrete element method (DEM) model for swelling of grains. A first order kinetic model was introduced to describe the swelling of a single grain, and subsequently implemented into the DEM code LIGGGHTS. Model validation was performed by comparing the time evolution of the expansion of a packed bed made of super absorbent polymer (SAP) particles obtained numerically and experimentally. It was demonstrated that the developed model can accurately predict the bed expansion. The validated model was then used to investigate the effect of material properties on the swelling behaviour using rice and SAP as the model materials. It is shown that the swelling depends significantly on material properties, as expected; the expansion of the powder bed made of rice is much lower than that of SAP. The developed model could be further advanced to study consequences of swelling phenomena in granular materials, such as segregation and heat generation.

Effect of super absorbent polymer and irrigation scheduling on growth attributes in acid lime

The experiment was undertaken at Fruit Research Station, Imalia, College of Agriculture, JNKVV, Jabalpur during the year 2019-20. The response of super absorbent polymer and irrigation scheduling on growth, yield and quality attributes in acid lime was evaluated. The experiment was laid out in Randomized Block Design with three replications and total 13 treatments combinations including control. Statistically analyzed data shows that among the treatments the maximum increase in plant height (0.65 m), canopy spread E-W direction (0.55 m) and N-S direction (0.57 m), shoot length (12.45 cm), leaf length (6.43 cm), leaf width (3.44 cm) and leaf area (14.58 cm2), fruit length (47.26 mm), fruit width (40.51 mm) and chlorophyll content (60.60 SPAD value) which was significantly superior among all the treatments and control.

Polyacrylamide modified geopolymer cement slurry: A potential barrier for channel behind casing

The present work is based on development of novel cement for water shut off through the application of Super Absorbent Polymer (Polyacrylamide) and Geopolymer (Fly ash). The hydration of Fly ash and polyacrylamide leads to plugging of channels in the cement sheath. The plugging characteristics of PAA was studied in saline water and distilled water. Further, decrease in contact angle with time complements the hydration of cement. The SEM analysis suggest the homogeneous dispersion FA and PAA in the cement sheath imparting the cement integrity. Cement slurry with 30% FA and 1% PAA demonstrates excellent compressive strength along with slurry displacement characteristics.

Effect of Super Absorbent Polymer on Germination and Growth of Safflower and Amaranth Sprouts

Effect of Super Absorbent Polymer on Germination and Growth of Safflower and Amaranth Sprouts

Effect of Super absorbent polymer on workability, strength and durability of Self consolidating concrete

This study presents the effect of super absorbent polymer (SAP) as internal curing agent on workability, durability and compressive strength of self-consolidating concrete (SCC). In order to estimate the internal curing efficiency of SAP in different curing conditions and curing ages, compressive strength and electrical resistivity tests have been performed. Homogenous and denser microstructure was formed by gradual release of water from SAP into pores created by SAP. Further pozzolanic reaction of fly ash has enhanced the strength and durability properties. High desorption rate of water from SAP in air curing condition resulted in an increased electrical resistivity and compressive strength. Compressive strength of internal cured SCC mixtures increased to 15-25% at 7 days and 10-19% at 28 days. Electrical resistivity values were increased 11-30% in water curing condition and 16-53% in air curing condition. The costs for 0.35w/b and 0.40 w/b at optimum internal cured SCC mixtures compared to control SCC mixtures were reduced to 9.39 and 9.70%, respectively.

Experimental Investigation on Flow Suppression and Modification of High Water Content Soil Using Water Absorbent Polymer and Fiber Cement Stabilization

Experimental Investigation on Flow Suppression and Modification of High Water Content Soil Using Water Absorbent Polymer and Fiber Cement Stabilization

Effects of Different Watering Intervals on Growth Performance of Abelmoschus Esculentus Presence with Super Absorbent Polymer Layer at the Root Zone with Moist Coir Dust Layers

Effects of Different Watering Intervals on Growth Performance of Abelmoschus Esculentus Presence with Super Absorbent Polymer Layer at the Root Zone with Moist Coir Dust Layers

Calculation Model for the Mixing Amount of Internal Curing Materials in High-strength Concrete based on Modified MULTIMOORA

Abstract The internal curing technology has been widely applied to high-strength concrete, for it can make the high-strength concrete marked by low shrinkage and durable frost resistance. The key to its extension and application lies in the reasonable mixing amount of internal curing materials. To address this problem, scholars have proposed a method for determining the water demand in internal curing; however, the water release of internal curing materials is difficult to obtain by measurement due to the mixing method. Therefore, this paper proposed a calculation model for the mixing amount of internal curing materials based on the modified MULTIMOORA method (Multi-Objective Optimization on the basis of Ratio Analysis plus full multiplicative form). First, different internal curing materials (super absorbent polymer (SAP), lightweight aggregate (LWA)) and pretreatment methods were selected to calculate their compressive strength, self-shrinkage and frost durability according to a proposed test scheme on the mixing amount of internal curing materials, and in such case, the comprehensive performance evaluation of the above indexes was turned into a multi-attribute decision-making problem. Second, the ordered weighted averaging (OWA) method and the entropy weight method were used to determine the subjective and objective weights of the indexes respectively, to eliminate the impact of outliers in the subjective evaluation values. Finally, the comprehensive performance of each test group was sorted using MULTIMOORA, and based on the sorting results and the calculation model, the mixing amount of internal curing materials was determined. The numerical example application results showed that the mixing amount of SAP curing material calculated based on the model herein was 1.276 kg/m3, and the mixing method adopted the pre-water absorption method with the total water-binder ratio unchanged. The numerical example evaluation results were in good agreement with the test results. The internal curing effect of SAP was better than that of LWA, and reached the best when the mixing amount was calculated at 25 times the water release rate and the requirement for the maximum total water diversion was met. The study may provide new ideas for extension and application of the internal curing technology.

Improved fire resistance of cold-formed steel walls by using super absorbent polymers

Fire resistance is an important concern in the design of steel structures. The fire protection mechanism of traditional methods is to cover the external surface of steel members and delay fire-induced heat transfer. This paper develops an innovative solution to improve the structural fire resistance using super absorbent polymers (SAPs) with an experimental study to successfully demonstrate the effect of SAPs on cold-formed steel (CFS) walls. The SAP insulation material was filled in the cavity of CFS walls to provide thermal insulation and absorb heat. Six 1.1 m × 1.1 m CFS walls with SAP insulation materials inside were prepared and subjected to the ISO 834 time-temperature curve. During the experiments, a large amount of water vapor was observed from the SAP insulation materials, effectively removing heat and providing fire protection. The effects of various combinations of SAP insulation materials and steel studs and different configurations of CFS walls on the fire resistance are discussed. The results show that increasing the stud web depth, using autoclaved lightweight concrete (ALC) boards and SAP insulation materials can substantially improve the fire resistance of CFS walls. An optimal configuration of CFS walls with ALC boards as the face-layer sheathing and SAP insulation materials in the cavity of the rectangle hollow section studs was proposed and showed high heat consumption and low damage during fire exposure, which was supported by the maximum temperature of the steel studs being less than 150 °C after exposure to ISO 834 fire for 2 h. Finally, a possible application scenario for the SAP material was proposed for the fire protection of steel structures.