Functionalized Multiwall Carbon Nanotubes For Efficiency Enhancement Used Of Nitrogenous Fertilizer In Paddy

• Main Author: Mohamad Yatim, Norazlina
• Format: Thesis
• Language: English; English
• Published: 2016
• Subjects: T Technology (General); TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.utem.edu.my/id/eprint/20513/1/Functionalized%20Multiwall%20Carbon%20Nanotubes%20For%20Efficiency%20Enhancement%20Used%20Of%20Nitrogenous%20Fertilizer%20In%20Paddy.pdf; http://eprints.utem.edu.my/id/eprint/20513/2/Functionalized%20Multiwalled%20Carbon%20Nanotubes%20For%20Efficiency%20Enhancement%20Used%20Of%20Nitrogenous%20Fertilizer%20In%20Paddy.pdf; http://eprints.utem.edu.my/id/eprint/20513/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=105860

The efficient use of urea fertilizer (UF) as an important nitrogen (N) source in the rice production has been a concern. The main problem is significant amount of the N fertilizer is lost during the year of application. Various studies that had adequately addressed the issue by using UF, which contains high amounts of N (47%) have so far had little success. Nanotechnology advancements in nutrition strategies involving multiwalled carbon nanotubes (MWCNTs) have attempted to provide solutions for N losses and low N use efficiency (NUE) by plants. However, agglomerates of MWCNTs limit their efficient mobility properties. Since a high degree of MWCNTs functionalization would lead to separation of nanotubes bundle, advanced N Nano-carrier is developed based on f-MWCNTs grafted with UF to produce urea-MWCNTs (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and NUE. The grafted N can be absorbed and utilized by rice efficiently to overcome the N propensity for loss from soil‐plant systems when UFMWCNTs are applied as fertilizer. Screening process parameters were structured via Plackett Burman experimental design of experiment involving nine identified factors, which were the amount of MWCNTs, percentage of functionalization, stirring time, stirring temperature, agitation, sonication frequency, sonication temperature, sonication time and amount of ammonium chloride with corresponding response of Total N attached on the surface of MWCNTs. As a result, functionalization and amount of MWCNTs used were found to be the most significant factors and chosen for further optimization processes. Analyses were structured via the Response Surface Methodology based on a five-level Central Composite Design consisting of f-MWCNTs amount between 0.10–0.60wt% and functionalization reflux time varying from 12-24hrs as the design factors. The individual and interaction effects between the specified factors and the corresponding responses (NUE, NU) were investigated. The UF-MWCNTs with optimized 0.5wt% f-MWCNTs treated at 21hrs functionalization reflux time achieved tremendous NUE up to 96% and NU at 1180mg/pot. A significant model term (p-value < 0.05) for NUE and NU responses were confirmed by the ANOVA of two quadratic models. Homogeneous dispersion with non-agglomerate features was observed on UF-MWCNTs via FESEM and TEM. Direct evidence regarding the physical translocation of biodegraded f-MWCNTs through phospholipid bilayers into plant roots involving soil-plant interaction via mass flow route and direct penetration into the subcellular region of the plant cells were revealed via TEM imaging investigation. Surface functionalization was strongly suggested to have a bigger effect on the translocation of f-MWCNTs than the size factor. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs approach provides a promising strategy in enhancing plant nutrition for rice.