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Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer.

Zhou Z, Du C, Li T, Shen Y, Zhou J - Sci Rep (2015)

Bottom Line: Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear.The nutrient-release model of CRF post-treated at 30 °C was the inverse "L" curve, but an increased duration of the post-treatment had no effect.The nutrient-release model was "S" curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.

ABSTRACT
Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse "L" curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was "S" curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies.

No MeSH data available.


Surface morphological structures of membranes from CRF post-treated at 30°C, 60°C, and 80°C for 2 h and 8 h, factorially.(A–F): height images of membranes post-treated at 30 °C for 2 h (A), 30 °C for 8 h (B), 60°C for 2 h (C), 60 °C for 8 h (D), 80 °C for 2 h (E), and 80 °C for 8 h (F); a–f: phase images of membranes post-treated at 30 °C for 2 h (a), 30 °C for 8 h (b), 60°C for 2 h (c), 60 °C for 8 h (d), 80 °C for 2 h (e), and 80 °C for 8 h (f).
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f6: Surface morphological structures of membranes from CRF post-treated at 30°C, 60°C, and 80°C for 2 h and 8 h, factorially.(A–F): height images of membranes post-treated at 30 °C for 2 h (A), 30 °C for 8 h (B), 60°C for 2 h (C), 60 °C for 8 h (D), 80 °C for 2 h (E), and 80 °C for 8 h (F); a–f: phase images of membranes post-treated at 30 °C for 2 h (a), 30 °C for 8 h (b), 60°C for 2 h (c), 60 °C for 8 h (d), 80 °C for 2 h (e), and 80 °C for 8 h (f).

Mentions: AFM measurements were used to study the surface morphology of membranes from a CRF post-treated at 30 °C, 60 °C, and 80 °C for 2 h and 8 h, respectively. Figure 6 shows the three dimensional height images (A–F) and phase images (a–f) from AFM. It can be clearly observed from the three dimensional height images as well as the phase images that the membranes post-treated at 60 °C and 80 °C were smoother than those at 30 °C. Table 1 represents the average roughness (Ra), root mean square roughness (Rq), and maximum roughness (Rmax), which were calculated using AFM software (NanoScope Analysis). There was a similar decreasing trend in membrane Ra, Rq, and Rmax from a CRF post-treated at 30 °C for 2 h and 8 h, 60 °C for 2 h and 8 h, and 80 °C for 2 h and 8 h. Membranes post-treated at 30 °C were the roughest, whereas membrane roughness was no different between 60 °C and 80 °C. Higher temperatures may contribute to polymer remodeling, and lead to more compact membranes with smoother surfaces.


Thermal post-treatment alters nutrient release from a controlled-release fertilizer coated with a waterborne polymer.

Zhou Z, Du C, Li T, Shen Y, Zhou J - Sci Rep (2015)

Surface morphological structures of membranes from CRF post-treated at 30°C, 60°C, and 80°C for 2 h and 8 h, factorially.(A–F): height images of membranes post-treated at 30 °C for 2 h (A), 30 °C for 8 h (B), 60°C for 2 h (C), 60 °C for 8 h (D), 80 °C for 2 h (E), and 80 °C for 8 h (F); a–f: phase images of membranes post-treated at 30 °C for 2 h (a), 30 °C for 8 h (b), 60°C for 2 h (c), 60 °C for 8 h (d), 80 °C for 2 h (e), and 80 °C for 8 h (f).
© Copyright Policy - open-access
Related In: Results  -  Collection

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f6: Surface morphological structures of membranes from CRF post-treated at 30°C, 60°C, and 80°C for 2 h and 8 h, factorially.(A–F): height images of membranes post-treated at 30 °C for 2 h (A), 30 °C for 8 h (B), 60°C for 2 h (C), 60 °C for 8 h (D), 80 °C for 2 h (E), and 80 °C for 8 h (F); a–f: phase images of membranes post-treated at 30 °C for 2 h (a), 30 °C for 8 h (b), 60°C for 2 h (c), 60 °C for 8 h (d), 80 °C for 2 h (e), and 80 °C for 8 h (f).
Mentions: AFM measurements were used to study the surface morphology of membranes from a CRF post-treated at 30 °C, 60 °C, and 80 °C for 2 h and 8 h, respectively. Figure 6 shows the three dimensional height images (A–F) and phase images (a–f) from AFM. It can be clearly observed from the three dimensional height images as well as the phase images that the membranes post-treated at 60 °C and 80 °C were smoother than those at 30 °C. Table 1 represents the average roughness (Ra), root mean square roughness (Rq), and maximum roughness (Rmax), which were calculated using AFM software (NanoScope Analysis). There was a similar decreasing trend in membrane Ra, Rq, and Rmax from a CRF post-treated at 30 °C for 2 h and 8 h, 60 °C for 2 h and 8 h, and 80 °C for 2 h and 8 h. Membranes post-treated at 30 °C were the roughest, whereas membrane roughness was no different between 60 °C and 80 °C. Higher temperatures may contribute to polymer remodeling, and lead to more compact membranes with smoother surfaces.

Bottom Line: Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear.The nutrient-release model of CRF post-treated at 30 °C was the inverse "L" curve, but an increased duration of the post-treatment had no effect.The nutrient-release model was "S" curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.

ABSTRACT
Controlled-release fertilizers (CRF) use a controlled-release technology to enhance the nutrient use efficiency of crops. Many factors affect the release of nutrients from the waterborne polymer-coated CRF, but the effects of thermal post-treatments remain unclear. In this study, a waterborne polyacrylate-coated CRF was post-treated at different temperatures (30 °C, 60 °C, and 80 °C) and durations (2, 4, 8, 12, and 24 h) after being developed in the Wurster fluidized bed. To characterize the polyacrylate membrane, and hence to analyze the mechanism of nutrient release, Fourier transform mid-infrared spectroscopy, scanning electron microscopy, and atomic force microscopy were employed. The nutrient-release model of CRF post-treated at 30 °C was the inverse "L" curve, but an increased duration of the post-treatment had no effect. The nutrient-release model was "S" curve and nutrient-release period was enhanced at higher post-treatment temperatures, and increased post-treatment duration lengthened slowed nutrient release due to a more compact membrane and a smoother membrane surface as well as a promoted crosslinking action. CRF equipped with specified nutrient-release behaviors can be achieved by optimizing the thermal post-treatment parameters, which can contribute to the development and application of waterborne polymer-coated CRF and controlled-release technologies.

No MeSH data available.