scholarly journals Superabsorbent Polymer With Excellent Water/Salt Absorbency And Water Retention, And Fast Swelling Properties For Preventing Soil Water Evaporation

Author(s):  
Haizhou Tian ◽  
Sha Cheng ◽  
Jianghong Zhen ◽  
Ziqiang Lei

Abstract Superabsorbent polymers have important applications in many fields, but insufficiency of water/salt absorbency, water retention, and swelling rate limit its application development. Herein, we fabricated HEC-g-P (AA-co-AMPS)/laterite by aqueous solution polymerization, the structure and morphology of the superabsorbent polymer were characterized by FTIR, SEM and TG/DTG. The optimal water absorbency of the superabsorbent polymer were 1294 g/g, 177 g/g, and 119 g/g in distilled water, tap water, and 0.9 wt% NaCl solution, respectively. The superabsorbent polymer had good water retention and re-swelling properties at different temperatures, and fast water absorption rate, and reached swelling equilibrium at 5 min. The swelling mechanism of the superabsorbent polymer was explained by the pseudo-second-order swelling kinetics model and Ritger-Peppas model. The effect of the amount of hydrogel on the water evaporation rate in soil was studied, and it had a good effect.

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1891 ◽  
Author(s):  
Mingchang Zhang ◽  
Shaodi Zhang ◽  
Zhuoran Chen ◽  
Mingzhi Wang ◽  
Jinzhen Cao ◽  
...  

Sawdust, a cheap by-product of the timber and forestry industry, was considered as a framework structure to prepare superabsorbent polymer with acrylic acid (AA) and acrylamide (AM), the synthetic monomers. The effects of initiator content, crosslinker content, AA content, AM content, degree of neutralization of AA, and reaction temperature on the swelling rate of superabsorbent polymer were investigated. The synthesized polymer was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Under optimal synthesis conditions, the results showed that the swelling rate of the polymer in deionized water and 0.9% NaCl solution reached 738.12 and 90.18 g/g, respectively. The polymer exhibits excellent swelling ability, thermal stability, and reusability. After the polymer was introduced into the samples (soil or coal), the water evaporation rate of the samples was significantly reduced, and the saturated water holding capacity and pore structure were also significantly improved.


2019 ◽  
Vol 268 ◽  
pp. 04013
Author(s):  
Chamylle Rose Aquino ◽  
Fauline Deune Carlos ◽  
Francis Padua ◽  
Honeylet Tayactac ◽  
Adrienne Hera Zulueta ◽  
...  

This article reports the use of wastepaper pulp as a direct source of cellulose for producing superabsorbent polymer. The white papers obtained from the offices in Adamson University were cut into 1 inch square pieces and drenched with distilled water and borax. This procedure was done couple of times to achieve a pH of 8 and consistency of 1%-2%. Commercial cotton was used as control to compare and differentiate the properties and structures with the superabsorbent polymer (SAP). Various trials have shown the value of 60 acrylamide beads to produce SAP with optimum performance. FTIR analysis shows properties that are characteristics of cellulose-based SAP. In the present investigation, the influence of temperature, effect in varying salt concentrations, swelling rate and water retention at constant temperature were evaluated. The SAP’s maximum swelling capacity ranges from 0.6561 g to 1.0638 g regardless of the amount of NaCl used. The swelling rate of the SAP proves that it gets heavier with time. Hence, it can be implied that the ability of the SAP to retain water is good. The temperature dependence data revealed the sorption process was favorable at higher temperature. The SAP will absorb the highest amount of solution at 500C given that the solution is pure.


2013 ◽  
Vol 805-806 ◽  
pp. 1356-1361
Author(s):  
Pei Qi Wu ◽  
Cheng Zhang Zheng ◽  
Yu Jian He ◽  
Da Zhou Lin ◽  
Zi Jie Wu ◽  
...  

A novel superabsorbent composite has been prepared via aqueous solution polymerization of acrylic acid (AA) in the presence of PVP modified bentonite powder using N,N-methylenebisacrylamide (MBA) as a crosslinker and potassium persulfate (KPS) as an initiator. The amount of PVP modified bentonite in the superabsorbent affected on the ultimate water absorbency was optimized, and the swelling kinetics and water retention ability were systematically investigated. The composite structure was determined by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric Analyzer (TG) and the scanning electron microscopy (SEM). The results indicate that the superabsorbents with PVP modified bentonite own superior water-swelling capability and water retention ability.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qin Yu ◽  
Xiangguo Lu ◽  
Yubao Jin ◽  
Cui Zhang ◽  
Kuo Liu ◽  
...  

Microspheres have excellent sealing performances such as injectivity, bridging-off, deep migration, and deformation performances, but their plugging effects are limited by the fast swelling rate and poor viscoelasticity. In this study, we synthesized a novel modified microsphere with polymerizable surfactant monomers and cationic monomers. We investigated the influence factors on the swelling performance and rheological properties of the microspheres and explored the ways to improve the plugging performance of hydrophobic-associating microspheres. The association behaviors in aqueous media of poly(acrylamide-co-methacry loyloxyethyl trimethyl ammonium chloride-co-n-dodecyl poly(etheroxy acrylate) P(AM-DMC-DEA) are proven to be mediated by the DEA content. Moreover, the hydrophobic association interaction has a strong effect on the performance of microspheres such as swelling properties, the rheological performance, and plugging properties. The swelling properties of microsphere studies exhibited the slow swelling rate. The rheological performance measurements showed significant improvements; yield stress, and creep compliance increased rapidly from 404 to 2060 Pa and 3.89 × 10−4 to 1.41 × 10−2 1/Pa, respectively, with DEA content in microspheres rising from 0.0% to 0.22%. The plugging properties of microspheres were enhanced by the slow swelling performance and good viscoelasticity.


2012 ◽  
Vol 512-515 ◽  
pp. 2394-2398 ◽  
Author(s):  
Ji Hong Xu ◽  
De Xin Tan ◽  
Ling Yan Yan ◽  
Zhong Li

A novel poly(2-acrylamido-2-methylpropa-nesulfonicacid-co-acrylamide) / attapulgite (P(AMPS-co-AM)/APT) high-salt superabsorbent composite was synthesized through graft polymerization in aqueous solution by microwave irradiation. The structure of the composite was characterized by infrared spectra (FTIR).The influence of the content of monomer, microwave power and the ratio of attapulgite clay on water absorbency was investigated. The swelling behaviors and the water retention of Superabsorbent resin with different APT content were also examined. The results show that the graft copolymerization took place between APT and organic monomers. Adding an appropriate amount of APT in resin can effectively improve the absorption capacity and salt-water performance. Microwave power is 390W, APT amount is 7.5% (mass fraction),The water absorbency of resin in distilled water and 0.9wt% NaCl were 1460g / g and 114 g / g. The resin has a faster absorption rate and strong water retention, the appropriate increase the amount of APT can significantly speed up the rate of the resin absorbent and improve its water retention.


2019 ◽  
Vol 41 (4) ◽  
pp. 668-668
Author(s):  
Saud Hashmi Saud Hashmi ◽  
Saad Nadeem Saad Nadeem ◽  
Zahoor Awan Zahoor Awan ◽  
Adeel ur Rehman Adeel ur Rehman ◽  
Ahsan Abdul Ghani Ahsan Abdul Ghani

Superabsorbent hydrogels constitute a group of polymeric materials with three-dimensional network structure, which can swell to absorb an enormous amount of water or aqueous solutions. This property enables various commercial applications of hydrogels such as water holding capability in agriculture and superabsorbent material for baby diapers. Several novel superabsorbent hydrogels based on acrylic acid-co-acrylamide copolymers were synthesized under variation of copolymer compositions through free radical polymerization. N,N’methylenebisacrylamide (MBA) was used as a water soluble crosslinker and potassium persulphate (KPS) as an initiator. Effect of varying the copolymer composition, change in crosslinker concentration, and effect of environmental parameters (pH, temperature, and ion concentration) on both swelling capacity and swelling rate were examined. These gel shows maximum swelling at neutral pH-7, whereas increasing salt concentration in water decrease the swelling capacity. It was found interesting that an increase in crosslinker concentration from 0.020% to 0.16%, the swelling capacity decreases up to 70% while the swelling rate increases from 0.007g water/g dry hydrogel sec to 0.024g water/g dry hydrogel sec, respectively because there is a compromise exists between entropic spring forces between network connection points and the hydrostatic pressure of the water diffusing into the gels. Dynamic swelling curve obtained were fitted to the three different kinetic models namely Peleg’s kinetic model, pseudo 1st order as proposed by Lagergen and pseudo 2nd order kinetics. All these models provided a good agreement with the experimental data; However on the bases of statistical parameters (RMSE, R2 and X2) the Peleg’s model was selected as the most appropriate model for this study. Analyzing rate constant for Peleg’s models at different swelling temperatures disclosed that increasing temperature could only increase the swelling rate without affecting the swelling capacity of the hydrogels. Experimental values for rate constant k1 of Peleg’s model at different temperature shows a sharp decrease from 0.57545 at 30 oC to 0.1535 at 75 oC that contemplated the rate of swelling at 75 oC was 65% faster than that of 30 oC. The diffusion mechanisms in hydrogels were proven to be tailorable by increasing cross-linker concentration and temperature, leading towards the Fickian type diffusion behavior. The synthesized superabsorbent hydrogels were also tested for water retention applications in agriculture.


Fibers ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 61 ◽  
Author(s):  
Bruno Ribeiro ◽  
Tadaaki Uchiyama ◽  
Jun Tomiyama ◽  
Takashi Yamamoto ◽  
Yosuke Yamashiki

The use of sugarcane residues in mortar and concrete is believed to contribute to a reduction of costs and environmental problems, such as the reduction of mining of natural aggregates and incorrect disposal of the sugarcane residues. Bagasse fiber has a high water retention rate and thus may be considered as a countermeasure for urban heat islands. Because of these properties, bagasse fiber and bagasse sand were added into the preparation of the interlocking concrete blocks. An investigation of the flexural strength and the contribution of the sugarcane residues against an urban heat island was made. The results showed that, by adding 2.0% of bagasse fiber and 5.0% of bagasse sand in concrete, the flexural strength and the water retention content increased in comparison to the control composite. Moreover, the surface temperature and the water evaporation rate of the blocks were smaller in comparison to the control composite.


Author(s):  
Antti Lempinen

Compacted bentonite is the main candidate for buffer material in several plans for spent nuclear fuel repositories. One of its important properties is high swelling capacity, which is caused by interaction between water molecules and exchangeable cations. This interaction makes bentonite behave differently from capillary materials. In this article, a model for thermo-hydro-mechanical state of partially water saturated bentonite is presented. It couples the water retention and swelling properties with introduction of the swelling factor in effective strain. The Helmholz energy density determines the state with a relatively small set of independent parameters: swelling pressure, swelling factor, maximum confined water content and the reference state. The model parameters are determined from experimental data for FEBEX bentonite, and as a simple consistency check, confined suction curves are calculated and compared to test results. Consistency of the model with observations on nano- and microscale of bentonite is also discussed.


2019 ◽  
Vol 268 ◽  
pp. 04010 ◽  
Author(s):  
Ariel Melendres ◽  
Judy An Antang ◽  
Christian Jake Manacob

Different types of superabsorbent polymers (SAP) exhibiting varied absorbency properties were investigated for their performances at varying concentrations of an electrolyte. Water chemical potential, which is a function of concentration and pressure, was interpreted as a major parameter for absorbency and swelling properties of SAP. Superabsorbent polymers that were investigated gave different values of permeability which was carried out in a layer of swelled superabsorbent polymer. This result revealed differences on the structure of the superabsorbent polymers particularly on the crosslinking density. SAP’s absorbency properties were further tested and a correlation between the quantity of absorption and the chemical potential of water in terms of sodium chloride concentration was developed using experimental data on free swelling capacity and absorption under pressure. Results showed decreasing quantity of absorption by the superabsorbent polymers with decreasing chemical potential of water with higher reduction in the absorbency at higher pressure applied on the swelled SAP.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5071
Author(s):  
Jakub Misiewicz ◽  
Arkadiusz Głogowski ◽  
Krzysztof Lejcuś ◽  
Daria Marczak

Superabsorbent polymers (SAPs) are used in agriculture and environmental engineering to increase soil water retention. Under such conditions, the swelling pressure of the SAP in soil affects water absorption by SAP, and soil structure. The paper presents the results of swelling pressure of three cross-linked copolymers of acrylamide and potassium acrylate mixed at the ratios of 0.3%, 0.5% and 1.0% with coarse sand and loamy sand. The highest values of swelling pressure were obtained for the 1% proportion, for coarse sand (79.53 kPa) and loamy sand (78.23 kPa). The time required to reach 90% of swelling pressure for each type of SAP differs. Samples of coarse sand mixed with SAP K2 in all concentrations reached 90% of total swelling pressure in 100 min, while the loamy sand mixtures needed only about 60 min. The results were the basis for developing a model for swelling pressure of the superabsorbent and soil mixtures, which is a fully stochastic model. The conducted research demonstrated that the course of pressure increase depends on the available pore capacity and the grain size distribution of SAPs. The obtained results and the proposed model may be applied everywhere where mixtures of SAPs and soils are used to improve plant vegetation conditions.


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