A Novel Method for Studying the Re-Swelling Capacity of Superabsorbent Polymers in An Artificial Crack

2020 ◽  
Vol 35 (5) ◽  
pp. 996-1002
Author(s):  
Juanhong Liu ◽  
Haitao Yang ◽  
Yanpeng Xue ◽  
Zhaogui Lai ◽  
Hongguang Ji
Keyword(s):  
Superabsorbent Polymers ◽  
Swelling Capacity ◽  
Novel Method

scholarly journals Investigation of superabsorbent polymer absorbency at reduced chemical potential of water

2019 ◽  
Vol 268 ◽  
pp. 04010 ◽  
Author(s):  
Ariel Melendres ◽  
Judy An Antang ◽  
Christian Jake Manacob
Keyword(s):  
Chemical Potential ◽  
Chloride Concentration ◽  
Crosslinking Density ◽  
Superabsorbent Polymer ◽  
Sodium Chloride Concentration ◽  
Swelling Properties ◽  
Superabsorbent Polymers ◽  
Swelling Capacity ◽  
Major Parameter ◽  
Different Types

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.

scholarly journals Valorization of Superabsorbent Polymers from Used Disposable Diapers as Soil Moisture Conditioner

2017 ◽  
Author(s):  
Raymundo Sánchez-Orozco ◽  
Beatriz Timoteo-Cruz ◽  
Teresa Torres-Blancas ◽  
Fernando Ureña-Núñez
Keyword(s):  
Soil Moisture ◽  
Laboratory Experiments ◽  
Salt Solutions ◽  
Phaseolus Vulgaris L ◽  
Untreated Soil ◽  
Superabsorbent Polymers ◽  
Swelling Capacity ◽  
Disposable Diapers ◽  
External Stimuli ◽  
Seeds Germination

This study was conducted to explore the potential of superabsorbent polymers (SAPs) from used disposable diapers as soil moisture conditioner. Swelling behavior of the proposed hydrogel in response to external stimuli such as salt solutions, temperature and pH was studied. In addition, laboratory experiments were carried out to evaluate the effects of incorporation hydrogel on germination of bean (Phaseolus vulgaris L.) and pumpkin (C. pepo) seeds. The structure of the superabsorbent was characterized by Fourier transform infrared spectroscopy (FTIR). The results indicate that the proposed SAP exhibited a maximum swelling capacity of 189 g.g-1 of dry gel. It was observed that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. When this SAP was mixed with sandy soil, the mixture was able to lose water more slowly. The seeds germination and seedling growth was remarkably influenced by the application of 0.5, 1.0 and 2.0 w/w% of SAP compared to the untreated soil. Therefore, it follows that it is possible to take advantage of SAPs property from used disposable diapers to retain the moisture in soil as an alternative to value the use of such waste, showing that it has potential for diverse applications in agriculture.

scholarly journals VALORIZATION OF SUPERABSORBENT POLYMERS FROM USED DISPOSABLE DIAPERS AS SOIL MOISTURE RETAINER

2017 ◽  
Vol 5 (4) ◽  
pp. 105-117
Author(s):  
Raymundo Sánchez-Orozco ◽  
Beatriz Timoteo-Cruz ◽  
Teresa Torres-Blancas ◽  
Fernando Ureña-Núñez
Keyword(s):  
Soil Moisture ◽  
Laboratory Experiments ◽  
Phaseolus Vulgaris L ◽  
Untreated Soil ◽  
Superabsorbent Polymers ◽  
Swelling Capacity ◽  
Agricultural Applications ◽  
Disposable Diapers ◽  
External Stimuli ◽  
Seeds Germination

This study was conducted to explore the potential of superabsorbent polymers (SAPs) from used disposable diapers as soil moisture retainer. Swelling behavior of the proposed hydrogel in response to external stimuli such as salt solutions, temperature and pH was studied. In addition, laboratory experiments were carried out to evaluate the effects of incorporation hydrogel on germination of bean (Phaseolus vulgaris L.) and pumpkin (C. pepo) seeds. The structure of the used superabsorbent was characterized by Fourier transform infrared spectroscopy (FTIR). The results indicate that the proposed SAP exhibited a maximum swelling capacity of 189 g-g-1 of dry gel. It was observed that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. When this SAP was mixed with sandy soil, the mixture was able to lose water more slowly. The seeds germination and seedling growth was remarkably influenced by the application of 0.5, 1.0 and 2.0 w/w% of SAP compared to the untreated soil. Therefore, it follows that it is possible to take advantage of SAPs property from used disposable diapers to retain the moisture in soil as an alternative to value the use of such waste, showing that it has potential for agricultural applications.

scholarly journals Parameter Study of Superabsorbent Polymers (SAPs) for Use in Durable Concrete Structures

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1541 ◽  
Author(s):  
Laurence De Meyst ◽  
Els Mannekens ◽  
Maria Araújo ◽  
Didier Snoeck ◽  
Kim Van Tittelboom ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Hydration ◽  
Setting Time ◽  
Concrete Structures ◽  
Parameter Study ◽  
Particle Sizes ◽  
Hydration Kinetics ◽  
Superabsorbent Polymers ◽  
Swelling Capacity ◽  
Cross Linker

Superabsorbent polymers (SAPs) can be added to a concrete mixture to provide internal curing and reduce the risk for early-age shrinkage cracking. Hence, they can help to increase the overall durability of concrete structures. The type, swelling characteristics, kinetics of water release, amount and particle size of the SAPs will dictate their effectiveness for this purpose. In this paper, SAPs with different cross-linking degrees, particle sizes and amount of solubles are investigated. By varying these parameters, insight can be gained on the influence of each of these parameters on SAP properties such as the swelling capacity. In a next step, the SAPs can be implemented in mortar to assess their influence on mortar properties like workability, compressive strength or hydration kinetics. Based on these results, the ‘ideal’ SAP with tunable properties for a specific concrete application can be selected. For this purpose, an anionic SAP was synthesized with varying amounts of cross-linker and ground to particle sizes with d50 varying between 10 and 100 µm. The swelling capacity in demineralised water of 40 µm SAP particles increased with a decreasing degree of cross-linker from 66 g/g SAP with 1 mol% cross-linker to 270 g/g SAP in case of 0.15 mol% cross-linker, and was about three to four times larger than the swelling capacity in the prepared cement filtrate. The SAPs were tested for their effect on mortar workability, cement hydration kinetics and mechanical properties of the hardened mortar. With proper compensation for the absorbed water by the SAPs, the mortar workability was not negatively affected and the reduction in flow over the first two hours remained limited. The SAPs with the lowest swelling capacity, resulting in the smallest total amount of macro pores formed, showed the smallest negative effect on mortar compressive strength (a reduction of 23% compared to the reference after 28 days for an addition of 0.5 m% SAP) and a negligible effect on cement hydration. The difference in strength with the reference decreased as a function of mortar age. When using SAPs with particle sizes in the range of 10–100 µm, no significant differences between the studied particle sizes were found concerning the mortar properties. With the ease of upscaling in mind, the need to purify the SAPs and to remove the non-cross-linked soluble fraction was further investigated. It was shown that the solubles had no effect on the mortar properties, except for increasing the setting time with almost 100%.

scholarly journals Dewatering of Mine Tailings Slurries Using Superabsorbent Polymers (SAPs) Reclaimed from Industrial Reject of Baby Diapers: A Preliminary Study

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 785 ◽  
Author(s):  
Amal Sahi ◽  
Khadija El Mahboub ◽  
Tikou Belem ◽  
Abdelkabir Maqsoud ◽  
Mamert Mbonimpa
Keyword(s):  
Mine Tailings ◽  
Water Reuse ◽  
Mass Concentration ◽  
Economic Feasibility ◽  
Coarse Grained ◽  
Surface Deposition ◽  
Superabsorbent Polymers ◽  
Promising Alternative ◽  
Swelling Capacity ◽  
Preliminary Study

Traditional deposition of tailings slurry in a tailings storage facility (TSF) can create risks of dike failure. In order to minimize these risks and slurry spillage, the surface deposition technique of densified tailings (DT) through dewatering of the slurry has emerged. The DT technique has the potential to maximize water reuse, improve the shear strength of surface tailings, and reduce the ecological footprint of TSF. The consistency of DT covers a continuum ranging from thickened state, to paste state, to dry state. Despite its efficiency and economic feasibility, DT densification using thickeners sometimes proves unable to achieve the design target solids mass concentration (Cw%). Hence, the use of superabsorbent polymers (SAPs) seems to represent a promising alternative, owing to their higher water absorbent capacity. In this paper, superabsorbent polymers (SAPs) reclaimed from industrial reject of baby diapers (Na-polyacrylates) are explored as a promising alternative to mine tailings slurries dewatering. To this end, laboratory-scale dewatering tests have been performed using two grades of Na-polyacrylate SAPs (grade 1 SAP = SAG-A06P coarse-grained, and grade 2 = SAG-M01P-100 medium-grained) for the tailings slurries densification. A higher water absorbency (or swelling capacity) was observed using the coarser SAPs (SAG-A06P) compared to the finer SAPs (SAG-M01P-100). The preliminary results showed that a SAP volume dosage in the range 10–13 kg of SAP/m3 of slurry allowed achieving a final solids mass concentration (Cw%_final) ≥ 70%, despite the occurrence of gel-blocking phenomenon.

scholarly journals Prediction of the swelling capacity of salt-insensitive superabsorbent polymers in concrete by rheological measurements

2019 ◽  
Vol 289 ◽  
pp. 02004
Author(s):  
Oliver Mazanec ◽  
Alessander Assmann ◽  
Diana Eissmann
Keyword(s):  
Solid Particle ◽  
Pore Solution ◽  
High Strength ◽  
Test Methods ◽  
Particle Fraction ◽  
Superabsorbent Polymers ◽  
New Approach ◽  
Fine Grained ◽  
Rheological Measurements ◽  
Swelling Capacity

A study on the macroscopic viscosity of a flowable, fine-grained high-strength mortar was conducted in order to estimate the swelling capacity of two salt-insensitive superabsorbent polymers (SAPs). In doing so, rotational rheometer measurements of the mortar modified with dry pre-mixed SAP were performed at several water-to-cement ratios (W/C), i.e. in the range 0.32 to 0.40. The swelling capacity of each SAP was estimated by correlating the fitted macroscopic viscosity vs. solid particle fraction curve with the curve of the plain mortar without addition of SAP, produced at the same W/C. The swelling capacities were found to yield 28 g pore water per g dry SAP (g/g) and 35 g/g, respectively. In addition to this new approach, two more practical relevant test methods were evaluated with respect to swelling capacity: first, comparative mortar spread tests, which were based on the use of the same fresh mortars but with less amount of superplasticizer, and second, tea bag tests with plain SAP immersed in an artificial pore solution. Only minor differences were found for the estimated swelling capacities. Hence the conclusion may be drawn that all three test methods are suitable for determining the swelling capacity of SAP in a cementitious environment.

scholarly journals Effect of Absorptivity of Superabsorbent Polymers on Design of Cement Mortars

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5503
Author(s):  
Jan Fořt ◽  
Przemysław Migas ◽  
Robert Černý
Keyword(s):  
Functional Properties ◽  
Tap Water ◽  
Nacl Solution ◽  
Solution Ph ◽  
Superabsorbent Polymers ◽  
Cement Mortars ◽  
Flow Table ◽  
Swelling Capacity ◽  
Cement Based Materials ◽  
Properties Of Composites

The functional properties of composites modified by superabsorbent polymers (SAPs) strongly depend on the swelling capacity of applied SAPs. In this sense, three types of commercially available SAPs namely Cablock CT, Hydropam, and Creasorb SIS with different chemical composition and particle size distribution were studied in this manuscript to reveal the differences in absorptivity as can be viewed as pretests for their utilization in concrete composites. In addition, absorptivity in distilled water, tap water, and 0.1 M NaCl solution are examined for determining the SAPs response for the change of the solution pH. To overcome problems with the teabag method inaccuracy, the new method is introduced. Besides to quantitative evaluation of the SAPs absorptivity, the correlation for the absorption and desorption period as the function of SAPs residence time within the examined solution is proposed. To access the effect of selected SAPs on functional properties, optimization based on the flow table test is employed and mechanical parameters are determined after 7, 14, 28, and 90 days of curing. Obtained results refer to substantial differences between particular SAPs and contribute to the understanding of the effect of SAP on the functional properties of cement-based materials.

The removal and morphology of intact biofilms from implanted venous access devices

1995 ◽  
Vol 53 ◽  
pp. 1020-1021
Author(s):  
M.A. Gregory ◽  
G.P. Hadley
Keyword(s):  
Patient Selection ◽  
Surgical Oncology ◽  
Venous Access ◽  
Common Procedure ◽  
Indwelling Catheters ◽  
Careful Patient ◽  
Novel Method ◽  
The Subject ◽  
Vascular Catheters ◽  
Venous Access Devices

The insertion of implanted venous access systems for children undergoing prolonged courses of chemotherapy has become a common procedure in pediatric surgical oncology. While not permanently implanted, the devices are expected to remain functional until cure of the primary disease is assured. Despite careful patient selection and standardised insertion and access techniques, some devices fail. The most commonly encountered problems are colonisation of the device with bacteria and catheter occlusion. Both of these difficulties relate to the development of a biofilm within the port and catheter. The morphology and evolution of biofilms in indwelling vascular catheters is the subject of ongoing investigation. To date, however, such investigations have been confined to the examination of fragments of biofilm scraped or sonicated from sections of catheter. This report describes a novel method for the extraction of intact biofilms from indwelling catheters.15 children with Wilm’s tumour and who had received venous implants were studied. Catheters were removed because of infection (n=6) or electively at the end of chemotherapy.

Sign in / Sign up

Export Citation Format

Share Document