One of the ways of overcoming the cost of irrigation is through in-situ water harvesting at the plant roots. Super absorbent polymer (SAP) can facilitate water harvesting at the plant roots. This study attempted to as...One of the ways of overcoming the cost of irrigation is through in-situ water harvesting at the plant roots. Super absorbent polymer (SAP) can facilitate water harvesting at the plant roots. This study attempted to assess the effect of SAP on plant available water (PAW) of different soils. In this study, SAP was sequentially added at the rate of 0.2%, 0.3% and 0.5% of the soil weight and its impact assessed in clay, sandy clay and sandy loam soils. The moisture retention characteristics of the original and SAP treated soils were studied using soil water retention curves (SWRC) and results modelled using Gardner model. PAW was estimated from SWRC as the difference between moisture content at 1.5 and 3 bar in all soils. The difference in PAW between original and treated soils was assessed at 5% level of significance. The WRC of all the samples was adequately found to be described by the Gardner model (Coefficient of determination R<sup>2</sup> ≥ 98% and residual standard error (RSE) ≤ 0.04). SWRC changed with increase in SAP percentage in clay, sandy clay and sandy loam soils. Clay had a higher change in water retention then sandy clay and lastly sandy loam. Plant available water content (PAW) in all soils increased. In clay soil it increased with increase in SAP from 0.3291 at zero SAP to 0.6223 at 0.5% SAP. Sandy clay soil increased in PAW from 0.2721 at zero SAP to 0.5335 at 0.5% SAP and Sandy loam soils from 0.1691 at zero SAP to 0.3461 at 0.5% SAP. Hence, from the study SAP can be used to conserve irrigation water in the plant roots and therefore reducing the cost since PAW has been increased.展开更多
Super absorbent polymers (SAPs) are gradually being applied in concrete production as internal curing agents.SAP can effectively reduce early age autogenous shrinkage of concrete,alleviate the hazards caused by concre...Super absorbent polymers (SAPs) are gradually being applied in concrete production as internal curing agents.SAP can effectively reduce early age autogenous shrinkage of concrete,alleviate the hazards caused by concrete cracking and improve its freeze–thaw resistance.However,the relationships between SAP dosage,SAP particle size and the water–cement ratio of concrete have certain influences on the evolution of the compressive strength of SAP-incorporated concrete.In this study,experiments were conducted to investigate the relationships between the water–cement ratio of concrete,the SAP dosage and SAP particle size.The significant factors influencing concrete strength are determined and equations are proposed for predicting the strength of SAP-incorporated concrete at 3,7 and 28 days.The findings from this study,such as the SAP dosage should not be larger than 0.2%,are expected to form a theoretical basis for the rational use of SAP as an additive to concrete.展开更多
The effect of super absorbent polymer（SAP） on the formation of tetrahydrofuran（THF） hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP ...The effect of super absorbent polymer（SAP） on the formation of tetrahydrofuran（THF） hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP formed THF hydrate completely during the same cooling process.The corresponding induction time was 16-29 min,14-31 min,respectively,which was obviously shorter than that of THF solution samples without SAP（25-62 min）.It indicated that SAP accelerated the formation of THF hydrate.At the same time,the pictures of hydrate formation with and without SAP had been compared.It was found that SAP did not change the morphology of the hydrate.Finally,the mechanism of SAP promoting effect on the formation of THF hydrate was suggested.展开更多
A super-absorbent polymer is prepared by graft polymerizing acrylamide (AM) onto potato starch using eerie ammonium nitrate (CAN) and N, N'-methylene-bis-acrylamide (bisAM) as an initiator and cross-linking agent ...A super-absorbent polymer is prepared by graft polymerizing acrylamide (AM) onto potato starch using eerie ammonium nitrate (CAN) and N, N'-methylene-bis-acrylamide (bisAM) as an initiator and cross-linking agent respectively, and then subjecting the potato starch- poly(acrylamide) (PAM) graft copolymer (SPAM) to alkaline saponification. The water absorbency (WA) of the sample is nearly 5000 g H2O/g for dry sample in 24 h at room temperature and is far larger than that of reported in the literature([1]). The variables affecting the WA were investigated and optimiz;ed, they were: concentrations of potato starch, AM, CAN and bisAM were 26.3 g/L, 1.14 mol/L, 10.3 mmol/L and 0.53 mmol/L, respectively. The amount of sodium hydroxide was 15 g and the temperatures of graft copolymerization and saponification reactions were 60 degrees C and 95 degrees C. The time of graft copolymerization and saponification reactions was 2 h, respectively.展开更多
Coating seeds with water absorbent materials can improve their survival, especially for those planted indrought or barren areas. In this study, effects of five kinds of super absorbent polymers （SAPs） on seed germin...Coating seeds with water absorbent materials can improve their survival, especially for those planted indrought or barren areas. In this study, effects of five kinds of super absorbent polymers （SAPs） on seed germinationand seedling growth of Caragana korshinskii under drought conditions were investigated. Our results showed that SAPcoatings could significantly improve the percentage and energy of seed germination, as well as reduce the relativeelectrical conductivity （REC）, proline, malondialdehyde （MDA）, H202 content, and peroxidase （POD） activity duringgermination. These results implied that seeds could uptake moisture from SAP coatings to alleviate drought-inducedoxidative stress and membrane damage, thus exhibiting a better vigor and germination performance. After coating C.korshinskii seeds with SAPs, more seedlings emerged and grew better. Under the combined influence of the waterabsorption capacity of SAP and other factors, the efficiencies of five SAP coatings are in the sequence D〉E〉B〉A〉C.The function of the SAP coating on promoting seedling survival was confirmed in Mu Us Sandy Land in Ordos, InnerMongolia Autonomous Region, China. The average seedling number of SAP D-coated seeds increased twofold on thatof naked seeds. Our results are expected to be helpful in understanding and utilizing SAP seed coatings in improvingplant survival under drought conditions.展开更多
文摘One of the ways of overcoming the cost of irrigation is through in-situ water harvesting at the plant roots. Super absorbent polymer (SAP) can facilitate water harvesting at the plant roots. This study attempted to assess the effect of SAP on plant available water (PAW) of different soils. In this study, SAP was sequentially added at the rate of 0.2%, 0.3% and 0.5% of the soil weight and its impact assessed in clay, sandy clay and sandy loam soils. The moisture retention characteristics of the original and SAP treated soils were studied using soil water retention curves (SWRC) and results modelled using Gardner model. PAW was estimated from SWRC as the difference between moisture content at 1.5 and 3 bar in all soils. The difference in PAW between original and treated soils was assessed at 5% level of significance. The WRC of all the samples was adequately found to be described by the Gardner model (Coefficient of determination R<sup>2</sup> ≥ 98% and residual standard error (RSE) ≤ 0.04). SWRC changed with increase in SAP percentage in clay, sandy clay and sandy loam soils. Clay had a higher change in water retention then sandy clay and lastly sandy loam. Plant available water content (PAW) in all soils increased. In clay soil it increased with increase in SAP from 0.3291 at zero SAP to 0.6223 at 0.5% SAP. Sandy clay soil increased in PAW from 0.2721 at zero SAP to 0.5335 at 0.5% SAP and Sandy loam soils from 0.1691 at zero SAP to 0.3461 at 0.5% SAP. Hence, from the study SAP can be used to conserve irrigation water in the plant roots and therefore reducing the cost since PAW has been increased.
文摘Super absorbent polymers (SAPs) are gradually being applied in concrete production as internal curing agents.SAP can effectively reduce early age autogenous shrinkage of concrete,alleviate the hazards caused by concrete cracking and improve its freeze–thaw resistance.However,the relationships between SAP dosage,SAP particle size and the water–cement ratio of concrete have certain influences on the evolution of the compressive strength of SAP-incorporated concrete.In this study,experiments were conducted to investigate the relationships between the water–cement ratio of concrete,the SAP dosage and SAP particle size.The significant factors influencing concrete strength are determined and equations are proposed for predicting the strength of SAP-incorporated concrete at 3,7 and 28 days.The findings from this study,such as the SAP dosage should not be larger than 0.2%,are expected to form a theoretical basis for the rational use of SAP as an additive to concrete.
文摘The effect of super absorbent polymer（SAP） on the formation of tetrahydrofuran（THF） hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP formed THF hydrate completely during the same cooling process.The corresponding induction time was 16-29 min,14-31 min,respectively,which was obviously shorter than that of THF solution samples without SAP（25-62 min）.It indicated that SAP accelerated the formation of THF hydrate.At the same time,the pictures of hydrate formation with and without SAP had been compared.It was found that SAP did not change the morphology of the hydrate.Finally,the mechanism of SAP promoting effect on the formation of THF hydrate was suggested.
文摘A super-absorbent polymer is prepared by graft polymerizing acrylamide (AM) onto potato starch using eerie ammonium nitrate (CAN) and N, N'-methylene-bis-acrylamide (bisAM) as an initiator and cross-linking agent respectively, and then subjecting the potato starch- poly(acrylamide) (PAM) graft copolymer (SPAM) to alkaline saponification. The water absorbency (WA) of the sample is nearly 5000 g H2O/g for dry sample in 24 h at room temperature and is far larger than that of reported in the literature([1]). The variables affecting the WA were investigated and optimiz;ed, they were: concentrations of potato starch, AM, CAN and bisAM were 26.3 g/L, 1.14 mol/L, 10.3 mmol/L and 0.53 mmol/L, respectively. The amount of sodium hydroxide was 15 g and the temperatures of graft copolymerization and saponification reactions were 60 degrees C and 95 degrees C. The time of graft copolymerization and saponification reactions was 2 h, respectively.
基金supported by the Fundamental Research Funds for the Central Universities(No.BLX2013023)the National Natural Science Foundation of China(Nos.31271807 and 31501144)the Beijing Natural Science Foundation of China(No.6162020)
文摘Coating seeds with water absorbent materials can improve their survival, especially for those planted indrought or barren areas. In this study, effects of five kinds of super absorbent polymers （SAPs） on seed germinationand seedling growth of Caragana korshinskii under drought conditions were investigated. Our results showed that SAPcoatings could significantly improve the percentage and energy of seed germination, as well as reduce the relativeelectrical conductivity （REC）, proline, malondialdehyde （MDA）, H202 content, and peroxidase （POD） activity duringgermination. These results implied that seeds could uptake moisture from SAP coatings to alleviate drought-inducedoxidative stress and membrane damage, thus exhibiting a better vigor and germination performance. After coating C.korshinskii seeds with SAPs, more seedlings emerged and grew better. Under the combined influence of the waterabsorption capacity of SAP and other factors, the efficiencies of five SAP coatings are in the sequence D〉E〉B〉A〉C.The function of the SAP coating on promoting seedling survival was confirmed in Mu Us Sandy Land in Ordos, InnerMongolia Autonomous Region, China. The average seedling number of SAP D-coated seeds increased twofold on thatof naked seeds. Our results are expected to be helpful in understanding and utilizing SAP seed coatings in improvingplant survival under drought conditions.
