Adsorption of a Polymeric Siloxane Surfactant on Carbon Black Particles Dispersed in Mixtures of Water with Polar Organic Solvents

Lin, Yining; Smith, Thomas W.; Alexandridis, Paschalis

doi:10.1006/jcis.2002.8638

Cited by 66 publications

(37 citation statements)

References 26 publications

(33 reference statements)

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“…The volume of adsorbed layer of chitosan was calculated by subtracting the volume of an uncoated PLGA NP from that of a chitosan-PLGA NP with a spherical shape assumed [21]. The ratio of the mass of adsorbed chitosan per unit weight of PLGA versus the volume of adsorbed chitosan (defined as the density of adsorbed chitosan layer per unit weight of PLGA) was plotted against the initial chitosan concentration.…”

Section: Chitosan Adsorptionmentioning

confidence: 99%

Understanding the adsorption mechanism of chitosan onto poly(lactide-co-glycolide) particles

Guo

Gemeinhart

2008

European Journal of Pharmaceutics and Biopharmaceutics

112

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Polyelectrolyte-coated nanoparticles or microparticles interact with bioactive molecules (peptides, proteins or nucleic acids) and have been proposed as delivery systems for these molecules. However, the mechanism of adsorption of polyelectrolyte onto particles remains unsolved. In this study, cationic poly(lactide-co-glycolide) (PLGA) nanoparticles were fabricated by adsorption of various concentrations of a biodegradable polysaccharide, chitosan (0-2.4 g/L), using oil-in-water emulsion and solvent evaporation techniques. The particle diameter, zeta-potential, and chitosan adsorption of chitosan coated PLGA nanoparticles confirmed the increase of polyelectrolyte adsorption. Five adsorption isotherm models (Langmuir, Freundlich, Halsey, Henderson and Smith) were applied to the experimental data in order to better understand the mechanism of adsorption. Both particle diameter and chitosan adsorption increased with chitosan concentration during adsorption. A good correlation was obtained between PLGA-chitosan nanoparticle size and adsorbed chitosan on the surface, suggesting the increased particle size was primarily due to the increased chitosan adsorption. The zeta-potential of chitosan-coated PLGA nanoparticles was positive and increased with chitosan adsorbed until a maximum value (+55 mV) was reached at approximately 0.4-0.6 g/L; PLGA nanoparticles had a negative zeta-potential (−20 mV) prior to chitosan adsorption. Chitosan adsorption on PLGA nanoparticles followed a multilayer adsorption behavior, although the Langmuir monolayer equation held at low concentrations of chitosan. The underlying reasons for adsorption of chitosan on PLGA nanoparticles were thought to be the cationic nature of chitosan, high surface energy and microporous non-uniform surface of PLGA nanoparticles.

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Section: Chitosan Adsorptionmentioning

confidence: 99%

Understanding the adsorption mechanism of chitosan onto poly(lactide-co-glycolide) particles

Guo

Gemeinhart

2008

European Journal of Pharmaceutics and Biopharmaceutics

112

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“…Due to all these reasons, many environmental and public health regulatory authorities have fixed stringent limits for anionic detergent as standard 0.5 mg/L for drinking water and relaxable up to 1.0 mg/L for other purposes (Rao, 1995). Surfactants removal operations involve processes such as chemical and electrochemical oxidation (Lissens, et al, 2003;Mozia, et al, 2005), membrane technology (Sirieix-Plénet, et al, 2003;Kowalska, et al, 2004;Fernández , et al, 2005), chemical precipitation (Shiau, et al, 1994;Talens-Alesson, et al, 2002), photocatalytic degradation (Rao and Dube, 1996;Ohtaki, et al, 2000;Zhang, et al, 2003), adsorption (Ogita, et al, 2000;Lin, et al, 2002;Adak, et al, 2005) and various biological methods (Matthew and Malcolm, 2000;Dhouib, et al, 2003;Chen, et al, 2005). Each has its merits and limitation in application.…”

Section: Introductionmentioning

confidence: 99%

Removal of surfactant from industrial wastewaters by coagulation flocculation process

Aboulhassan¹,

Souabi²,

Yaacoubi

et al. 2006

Int. J. Environ. Sci. Technol.

185

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Surfactants are among the most widely disseminated xenobiotics that contribute significantly to the pollution profile of sewage and wastewaters of all kinds. Among the currently employed chemical unit processes in the treatment of wastewaters, coagulation-flocculation has received considerable attention for yielding high pollutant removal efficiency. Jar-test experiments are employed in order to determine the optimum conditions for the removal of surfactants, COD and turbidity in terms of effective dosage, and pH control. Treatment with FeCl 3 proved to be effective in a pH range between 7 and 9. The process is very effective in the reduction of surfactants and COD, the removals are 99 and 88 % respectively, and increased BOD 5 /COD index from 0.17 to 0.41. In addition to precipitation coagulation process, adsorptive micellar flocculation mechanism seems contribute to the removal of surfactants and organic matters from this rejection.

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“…11,14 The shape of an adsorption isotherm shows the nature of the process. The most frequently observed adsorption isotherms involving carbon materials are of the Langmuir or the Freundlich type, 8,11,12,16 differing in the existence of a stable maximum (monolayer) surface coverage. This is connected to the amount of surfactant that is required to obtain a homogeneous and stable dispersion of CB particles in the liquid phase.…”

Section: Introductionmentioning

confidence: 99%

“…7-10 CB is also used for the adsorption of molecules from air or from aqueous media. [11][12][13][14] In some applications, CB is also combined with other carbon materials, e.g., graphite. 15 All of these applications depend on several properties of the CB powder, such as the particle size, the morphology of aggregates, the microstructure, and the chemical nature of the particle surface.…”

Section: Introductionmentioning

confidence: 99%

Influence of dispersing additives on the conductivity of carbon black pigment dispersion

et al. 2011

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The influence of dispersing additives on the electrical conductivity of carbon black pigments dispersed in an organic medium was studied. Two dispersing additives were examined in combination with two different carbon blacks, a conductive carbon black and a nonconductive one. These carbon blacks differ in the size of their aggregates and in the amounts of surface oxygen groups. Both of the additives form a monolayer when adsorbed on either of the pigment surfaces. FTIR studies showed that chemical bonding of one of the additives on the surfaces of both pigments had occurred. Conductivity decreases with increasing additive concentration, but in the case of the chemically bonded additive, the conductivity of the dispersion remained high even at higher additive loadings. This study helps in understanding the effects such additives have on the specific conductivity of composite materials that contain dispersed carbon black pigment particles.

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Adsorption of a Polymeric Siloxane Surfactant on Carbon Black Particles Dispersed in Mixtures of Water with Polar Organic Solvents

Cited by 66 publications

References 26 publications

Understanding the adsorption mechanism of chitosan onto poly(lactide-co-glycolide) particles

Understanding the adsorption mechanism of chitosan onto poly(lactide-co-glycolide) particles

Removal of surfactant from industrial wastewaters by coagulation flocculation process

Influence of dispersing additives on the conductivity of carbon black pigment dispersion

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