Monolithic Polymer Devices

Roseman, Theodore J.; Cardarelli, Nate F.

doi:10.1201/9780429287398-2

Cited by 3 publications

(4 citation statements)

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“…The release of pesticides from CRF was usually understood from the adsorption capability and the permeability of the matrix. A higher adsorption capability would result in a slower release, a consequence of the lower equilibrium concentration in the medium. , The T 50 values for the pretilachlor release from organobentonites totally increased with increasing adsorption equilibrium constant K a (Tables and ). However, the upward curvature of the T 50 vs K a plot suggested a possible alteration of matrix permeability induced by the structural change in the interlayer (Figure S6 in the Supporting Information).…”

Section: Results and Discussionmentioning

confidence: 97%

“…The release of pesticides from the CRFs was usually understood from the adsorption capability and the permeability of the matrix. A higher adsorption capability and a lower permeability usually resulted in a slower release. , In the past decades, much attention has been paid to the development of organobentonites with high adsorption capacity and feasibility to regulate the adsorption capacity of organobentonites. − However, little is known about the effects of structural features, such as molecular structure, loading level, and orientation of modifying agents in the interlayer space, on the permeability of organobentonites. The release behavior from organobentonites was qualitatively interpreted from the adsorption capacity of the matrix. , …”

Section: Introductionmentioning

confidence: 99%

“…A higher adsorption capability and a lower permeability usually resulted in a slower release. 13,14 In the past decades, much attention has been paid to the development of organobentonites with high adsorption capacity and feasibility to regulate the adsorption capacity of organobentonites. 15−17 However, little is known about the effects of structural features, such as molecular structure, loading level, and orientation of modifying agents in the interlayer space, on the permeability of organobentonites.…”

Section: Introductionmentioning

confidence: 99%

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Thermodynamics and Kinetics of Pretilachlor Adsorption on Organobentonites for Controlled Release

Lou

et al. 2020

ACS Omega

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Thermodynamics and kinetics of pretilachlor adsorption on organobentonites modified with hexadecyltrimethyl ammonium chloride were investigated to reveal the structural effects of organobentonites on the interaction with pretilachlor and the diffusion of the herbicide and were related to the controlled release from organobentonites. The adsorption of pretilachlor was entropically driven by hydrophobic interaction. The entropy change dropped with increasing surfactant loading from 0.4 to 1.50 times the cation exchange capacity (CEC) of the bentonite used, corresponding to a decrease in the degree of freedom of pretilachlor molecules due to the enhanced order of surfactant in the interlayer. The kinetics of pretilachlor adsorption was well fitted to the pseudo-second-order model and related to the structural features of organobentonites. The enhanced packing density of the surfactant in the interlayer generally resulted in a reduction of the rate constant of the pretilachlor adsorption onto organobentonites. However, the stepwise increase in the basal spacing due to the surfactant arrangement transition, from lateral-monolayer to lateral-bilayer at a loading level of more than 0.8 × CEC, benefited the diffusion of pretilachlor and diminished the influence of the increase in surfactant packing density. The release of pretilachlor from organobentonites was predominated by Fickian diffusion, which could be understood from the adsorption thermodynamics and kinetics. The time taken for the release of 50% of active ingredient was 16–23 times that for the control formulation and exhibited a linear increase with the relative value of the equilibrium constant to the rate constant of pretilachlor adsorption.

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Section: Results and Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermodynamics and Kinetics of Pretilachlor Adsorption on Organobentonites for Controlled Release

Lou

et al. 2020

ACS Omega

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“…The release of pesticide from CRFs was usually understood from the adsorption capability and the permeability of the matrix. A higher adsorption capability and lower permeability of the matrix would result in a slower release. , XRD and TG analysis indicated an interaction between alginate and imidacloprid (Figure B). A previous study also illustrated a weak adsorption capability of bentonite toward the pesticide .…”

Section: Resultsmentioning

confidence: 99%

Structure Regulation of Bentonite-Alginate Nanocomposites for Controlled Release of Imidacloprid

Zhang

Shi

et al. 2020

ACS Omega

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To reveal the structure and release properties of bentonite-alginate nanocomposites, bentonite of different amounts was incorporated into alginate by the sol–gel route. The structure of the composites was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis and related to the swelling property of the matrix and the release of imidacloprid. Bentonite was subject to exfoliation into nanoplatelets and combined into the polymeric network within alginate hydrogel, exhibiting profound effects on the structure features and release properties of the composites. Bentonite was of good compatibility with alginate due to the hydrogen bonding and the electrostatic attraction between them. The polymer chains were found to intercalate into the interlayer gallery of the clay. The high specific area of the nanoplatelets of bentonite benefited the intimate contact with alginate and reduced the permeability of the composites. However, in the composites with clay content of more than 10%, the polymer was insufficient to accommodate the silicate sheets completely. The aggregation of the platelets destroyed the structure integrity of the composites, facilitating the diffusion of the pesticide. The release of imidacloprid was greatly retarded by incorporating into bentonite-alginate composites and dominated by Fickian diffusion depending on the permeability of the matrix. The time taken for 50% of the active ingredient to be released, T 50, first increased and then decreased with increasing clay content in the composites, reaching a maximum around a weight percentage of 10%, at which the T 50 value for imidacloprid release was about 2.5 times that for the release from pure alginate formulation.

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Kinetics of release of a model disperse dye from supersaturated cellulose acetate matrices

Papadokostaki

Petropoulos

1998

Journal of Controlled Release

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Monolithic Polymer Devices

Cited by 3 publications

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Thermodynamics and Kinetics of Pretilachlor Adsorption on Organobentonites for Controlled Release

Thermodynamics and Kinetics of Pretilachlor Adsorption on Organobentonites for Controlled Release

Structure Regulation of Bentonite-Alginate Nanocomposites for Controlled Release of Imidacloprid

Kinetics of release of a model disperse dye from supersaturated cellulose acetate matrices

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