Effect of Crosslinking Agent on Neem (<i>Azadirachta Indica A. Juss.</i>) Seed Oil (NSO) Encapsulated Microcapsules of κ -Carrageenan and Chitosan Polyelectrolyte Complex

Devi, Nirmala; Maji, Tarun K.

doi:10.1080/10601320903245524

Cited by 34 publications

(19 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Moreover, very few studies have considered the use of chitosan-derived systems for the controlled delivery of agrochemicals. Some notable examples include the delivery of neem seed oil (Devi and Maji, 2009), plant hormones (Quiñones et al, 2010;Fan et al, 2012) and fertilisers and herbicide (Teixeira et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

et al. 2013

View full text Add to dashboard Cite

h i g h l i g h t sDicyandiamide (DCD) was encapsulated in glyoxal-crosslinked chitosan hydrogel beads. Chitosan delayed the release of nitrification inhibitor DCD in water and soil. DCD release was controlled by glyoxal polymerisation inside chitosan. The higher glyoxal polymerisation the more delayed DCD release in water or in soil. The higher glyoxal polymerisation the less DCD encapsulated in the beads. a r t i c l e i n f o b s t r a c tUsing chemical inhibitors to reduce soil nitrification decreases emissions of environmental damaging nitrate and nitrous oxide and improves nitrogen use efficiency in agricultural systems. The efficacy of nitrification inhibitors such as dicyandiamide (DCD) is limited in soil due to biodegradation. This study investigated if the persistence of DCD could be sustained in soil by slow release from a chitosan hydrogel. DCD was encapsulated in glyoxal-crosslinked chitosan beads where excess glyoxal was (i) partly removed (C beads) or (ii) allowed to dry (CG beads). The beads were tested in water and in soil. The beads contained two fractions of DCD: one which was quickly released in water, and one which was not. A large DCD fraction within C beads was readily available: 84% of total DCD bead content was released after 9 h immersion in water, while between 74% and 98% was released after 7 d in soil under low to high moisture conditions. A lower percentage of encapsulated DCD was readily released from CG beads: 19% after 9 h in water, and 33% after 7 d in soil under high rainfall conditions. Kinetic analysis indicated that the release in water occurred by quasi-Fickian diffusion. The results also suggest that DCD release was controlled by bead erosion and the leaching of glyoxal derivatives, predominantly a glyoxal-DCD adduct whose release was positively correlated with that of DCD (R 2 = 0.99, p 6 0.0001). Therefore, novel chitosan/glyoxal composite beads show a promising slow-release potential in soil for agrochemicals like DCD.

show abstract

Section: Introductionmentioning

confidence: 99%

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

et al. 2013

View full text Add to dashboard Cite

show abstract

“…In according to the IR analysis, CMcell and CM-chit may interact spontaneously in aqueous solution, and form polymer complex similar to that formed between chitosan and other anionic polysacchrides. The resulting core-shell structures have showed good capacity to encapsulate pesticides (12) and drugs (22).…”

Section: Release Of Metolachlor From Gel Formulationsmentioning

confidence: 99%

“…It is water soluble and easily crosslinked, the resulting hydrogel has been used as carriers for pesticides (7)(8)(9)(10). Chitosan is produced by partial N-deacetylation of chitin, the second most abundant polysaccharide on earth, and has been used in delivery systems because of its biocompatible property (11,12). However, the solubility of chitosan in neutral water is poor, and its application as carrier in pesticide formulations was somewhat limited.…”

Section: Introductionmentioning

confidence: 98%

Characterizations of Blend Gels of Carboxymethylated Polysaccharides and their Use for the Controlled Release of Herbicide

Dong

et al. 2012

Journal of Macromolecular Science, Part A

View full text Add to dashboard Cite

Polysaccharide-derived polymers are good carriers for encapsulating bioactive compounds for their controlled delivery. Aiming at extending the release of herbicide metolachlor in water, the novel gel beads were prepared by crosslinking the blend solutions of carboxymethyl cellulose (CM-cell) and carboxymethyl chitosan (CM-chit), and then used as the carrier in controlled release formulations (CRFs). SEM observation showed the formation of micro-aggregates in blend gel beads, and FT-IR analysis confirmed strong interactions between the two polymers. DSC analysis indicated stronger bonding of water by blend gels than that by pure CM-cell gel. The higher encapsulation efficiency and slower release of herbicide metolachlor were obtained by using the blend gel beads as the carrier of CRFs instead of the commercial emulsible oil formulation. The release of herbicide from the blend gels was dominated by a mechanism of Fickian diffusion, and related to their rapid and low swelling in water.

show abstract

“…Temperature of decomposition at different weight loss (%) of NSO Thermal stability of chitosan-carrageenan microcapsules (as suggested by thermogravimetric analysis) was found to improve with the increase in the concentration of crosslinker. In case of various crosslinkers, glutaraldehyde crosslinked samples showed highest thermal stability followed by genipin and tannic acid (Devi & Maji, 2009b Formation of spherical beads with smooth surface and having particle sizes ranging from 1.21 to 1.40 mm in diameter was reported for sodium alginate beads (Kulkarni et al, 2000). The SEM photographs of capsules of sodium alginate matrix, crosslinked by glutaraldehyde and coated with natural rubber were shaped like an egg (Riyajan & Sakdapipanich, 2009).…”

Section: Characterizationmentioning

confidence: 99%

“…Juss.) seed oil (NSO) were prepared by encapsulation of natural liquid pesticide NSO in polyelectrolyte complexes of naturally occurring polymers namely carrageenan-chitosan (Devi & Maji, 2009a, 2009b gelatin-carrageenan (Devi & Maji, 2010) and gelatin-sodium carboxymethyl cellulose (Devi & Maji, 2011). Microencapsulation was carried out at the optimized ratio and pH for complexation between the biopolymers in order to get maximum yield and to form stable polyelectrolyte complex.…”

Section: Encapsulation and Controlled Release Of Nsomentioning

confidence: 99%

Neem Seed Oil: Encapsulation and Controlled Release - Search for a Greener Alternative for Pest Control

Devi¹,

Maji²

2011

Pesticides in the Modern World - Pesticides Use and Management

View full text Add to dashboard Cite

Effect of Crosslinking Agent on Neem (Azadirachta Indica A. Juss.) Seed Oil (NSO) Encapsulated Microcapsules of κ -Carrageenan and Chitosan Polyelectrolyte Complex

Cited by 34 publications

References 26 publications

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

Slow delivery of a nitrification inhibitor (dicyandiamide) to soil using a biodegradable hydrogel of chitosan

Characterizations of Blend Gels of Carboxymethylated Polysaccharides and their Use for the Controlled Release of Herbicide

Neem Seed Oil: Encapsulation and Controlled Release - Search for a Greener Alternative for Pest Control

Contact Info

Product

Resources

About