Superabsorbent hydrogels based on polysaccharides for application in agriculture as soil conditioner and nutrient carrier: A review

Slow release coating remedy for nitrogen loss from conventional urea: a review.

Environmentally friendly fertilizers: A review of materials used and their effects on the environment.

Preparation and characterization of slow-release fertilizer encapsulated by starch-based superabsorbent polymer

PLGA microspheres are widely studied for controlled release drug delivery applications, and many models have been proposed to describe PLGA degradation and erosion and drug release from the bulk polymer. Autocatalysis is known to have a complex role in the dynamics of PLGA erosion and drug transport and can lead to size-dependent heterogeneities in otherwise uniformly bulk-eroding polymer microspheres. The aim of this review is to highlight mechanistic, mathematical models for drug release from PLGA microspheres that specifically address interactions between phenomena generally attributed to autocatalytic hydrolysis and mass transfer limitation effects. Predictions of drug release profiles by mechanistic models are useful for understanding mechanisms and designing drug release particles.

Mathematical modeling of drug delivery from autocatalytically degradable PLGA microspheres — A review

To impede nitrogen loss due to leaching and NH3 volatilization, pristine urea particles are coated with synthetic polymers such as poly(acrylic acid) and polyethylene for the controlled release of ...

Parametric study of tumbling fluidized bed to evaluate nitrogen release characteristics of biopolymer-coated controlled release urea

Dynamic of Water Absorption in Controlled Release Fertilizer and its Relationship with the Release of Nutrient

The present study investigates the effect of fluid-bed process parameters on the diffusion coefficient of nitrogen release and coating homogeneity of controlled-release urea (CRU) produced in a rotary fluidized bed using polyvinyl-alcohol-modified starch as a coating material. An existing mathematical model was used to estimate the diffusion coefficient. The coefficient of variance of size distribution and coating mass variation are reported as a measure of coating homogeneity.

Statistical analysis suggested that the most influential process variables that govern urea release characteristics and coating homogeneity were (a) fluidizing gas temperature and (b) coating time. A moderate spray rate combined with longer coating time yielded the lowest diffusion coefficient for nutrient release. Elutriation as the result of elevated fluidizing gas temperature allowed a higher diffusion coefficient due to lower coating thickness. Burst release patterns were observed for granules with coating imperfections. The augmented temperature of fluidizing gas had a negative effect on coating mass and size distribution of CRU granules but the influence of longer coating time was positive.

Nutrient release characteristics and coating homogeneity of biopolymer coated urea as a function of fluidized bed process variables

Use of Multi-diffusion Model to Study the Release of Urea from Urea Fertilizer Coated with Polyurethane-like Coating (PULC)☆

A mathematical model for the reaction-diffusion equation is developed to describe the nutrient release profiles and degradation of poly(lactic acid) (PLA)-coated controlled-release fertilizer. A multi-diffusion model that consists of coupled partial differential equations is used to study the diffusion and chemical reaction (autocatalytic degradation) simultaneously. The model is solved using an analytical-numerical method. Firstly, the model equation is transformed using the Laplace transformation as the Laplace transform cannot be inverted analytically. Numerical inversion of the Laplace transform is used by employing the Zakian method. The solution is useful in predicting the nutrient release profiles at various diffusivity, concentration of extraction medium, and reaction rates. It also helps in explaining the transformation of autocatalytic concentration in the coating material for various reaction rates, times of reaction, and reaction-multi diffusion. The solution is also applicable to the other biodegradable polymer-coated controlled-release fertilizers.

https://www.mdpi.com/2073-4360/9/3/111/pdf

KuZilati KuShaari

Papers

Parametric study of tumbling fluidized bed to evaluate nitrogen release characteristics of biopolymer-coated controlled release urea

Dynamic of Water Absorption in Controlled Release Fertilizer and its Relationship with the Release of Nutrient

Nutrient release characteristics and coating homogeneity of biopolymer coated urea as a function of fluidized bed process variables

Use of Multi-diffusion Model to Study the Release of Urea from Urea Fertilizer Coated with Polyurethane-like Coating (PULC)☆

Reaction-Multi Diffusion Model for Nutrient Release and Autocatalytic Degradation of PLA-Coated Controlled-Release Fertilizer