Formula and process optimization of controlled‐release microcapsules prepared using a coordination assembly and the response surface methodology

Abstract

A model chlorpyrifos microcapsule was prepared using coordination assembly between Fe 31 and tannic acid (TA). The influence of independent variables such as the dropping rate of TA (X 1 ) and Fe 31 (X 3 ), the concentration of TA (X 2 ) and Fe 31 (X 4 ), and the reaction temperature (X 5 ) on the encapsulation efficiency (R 1 ) and release characteristics (R 2 ) of the microcapsule had been investigated, based on a central composite design with five factors and five levels. The results showed that the main factors influencing R 1 and R 2 were X 4 and X 2 , then the interaction between X 2 and X 4 , followed by X 5 and X 3 . The optimal formula mainly based on higher R 1 and lower R 2 were determined and then tested. The optimized conditions led to an encapsulation efficiency and cumulative release proportion of 97.12% 6 0.72% and 40.07% 6 0.53%, along with the average relative errors of predicted values being 1.78% and 21.60%, respectively.

Phoxim Microcapsules Prepared with Polyurea and Urea–Formaldehyde Resins Differ in Photostability and Insecticidal Activity

“…However, this not only increases the economic investment and labor of farmers but also adds more chemicals into the environment. Microencapsulation technology has received extensive attention in the domain of agrochemicals. , It provides isolation from the external environment by using various wall materials, which consequently improve the chemical stability of the active ingredients. Rapid advancements in microencapsulation are closely related to the following advantages: (1) microencapsulation can protect the active ingredients from being affected by environmental factors, such as air, sunlight, rain, and microorganisms; and (2) it can control the release rate of pesticides from microcapsules to prolong the duration of the pesticides and reduce their application frequency .…”

Tunable thermal, mechanical, and controlled-release properties of epoxy phenolic novolac resin microcapsules mediated by diamine crosslinkers

“…The release behavior of the four as-prepared MCs was investigated by adapting a previously reported method. 30 The mixture of hexane-ethyl alcohol solvents (160 : 20, v/v) was used as release medium owing to their excellent dissolving capacity for lipophilic Nd and shortening the trial period. Briey, the dried MC samples were accurately weighed and added in 100 mL of hexane-ethyl alcohol solvents and then transferred to a rotary shaker at 70 rpm and 30 C. Subsequently, 0.5 mL of the liquid was collected at predetermined intervals from the above system and simultaneously added into the same volume of hexaneethyl alcohol solvents.…”

Easily Tunable Membrane Thickness of Microcapsules by Using a Coordination Assembly on the Liquid-Liquid Interface

“…et al, 2017 ). The past few decades have seen significant advances of microencapsulation in drug delivery (Wang et al, 2006 ; De Koker et al, 2012 ; Simoes et al, 2015 ; Jia et al, 2017 ; Li H. et al, 2017 ), material industry (White et al, 2001 ; Su and Schlangen, 2012 ; Jamekhorshid et al, 2014 ), biomaterials (Parthasarathy and Martin, 1994 ; Zhi and Haynie, 2006 ; Kurayama et al, 2012 ; Ekanem et al, 2017 ; Zhao et al, 2017 ), agrochemicals (Li et al, 2016 , 2018 ; Liu et al, 2016 ; Liang et al, 2017 ), food industry (Xu et al, 2013 ), and other fields. There are numerous encapsulation methods focusing on in situ polymerization (Su et al, 2013 ; Zuo et al, 2014 ), interfacial polymerization (Wagh et al, 2009 ), spray drying (Zhang and Zhong, 2013 ), solvent evaporation (Lee et al, 2012 ) and so on.…”

“…In recent years, coordination complexes utilizing metal ions and natural products have attracted extensive interest from the scientific community due to their high environmental compatibility (Bentley and Payne, 2013 ; Ejima et al, 2013 ; Guo et al, 2014 ; Li et al, 2016 ; Rahim et al, 2016 ). These materials can be assembled onto planar or particulate substrates with a range of functionalities, including enhanced mechanical stability selection, permeability, and stimuli-responsiveness (Rahim et al, 2014 ; Ping et al, 2015 ; Ejima et al, 2016 ; Richardson et al, 2016 ).…”