A novel processing scheme for core—shell nano composites using controlled polymer adsorption

Somasundaran, P.; Chen, Tsung-Yuan; Sarkar, Diptabhas

doi:10.1007/s100190050108

Cited by 12 publications

(6 citation statements)

References 7 publications

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“…Figure 3 shows the ξ potential versus pH for three different slurry formulations: (a) as‐received alumina powder (not alkylated and without surfactant addition), (b) alumina powder that was not alkylated but dispersed in a solution containing 0.05 M C 12 TAB, and (c) decanol‐alkylated alumina powder dispersed with 0.05 M C 12 TAB. As expected from previous data 16,17 the isoelectric point for non‐alkylated alumina powder was measured to be approximately pH 9. The alumina powder that was not alkylated but dispersed in a solution containing 0.05 M C 12 TAB did not exhibit an isoelectric point, and remained positively charged over the entire pH range.…”

Section: Resultssupporting

confidence: 86%

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Bock

Lange

2006

Journal of the American Ceramic Society

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Alumina particles have successfully been alkylated via a condensation reaction between surface hydroxide sites and different, long chain alcohol molecules, specifically decanol, dodecanol, and octadecanol. These hydrophobic particles have been successfully dispersed in water using different C n TAB surfactant molecules, where n 5 10, 12, 14, 16. The effect of the length of the surfactant molecule and its concentration was quantified with rheological experiments. Rheology and conductivity measurements were used to determine the minimum amount of the surfactant needed to disperse the alkylated powder. Slurries formulated with the alkylated powder and the proper amount of C n TAB exhibited Newtonian rheology for n ! 10. n potential measurements showed that the surface charge on the particles was always positive confirming that the C n TAB molecules, with a positive head group, surrounded the alkylated particles. Such powder did not have an isoelectric point. In addition, the Newtonian behavior of the alkylated-alumina/C n TAB slurry systems were independent of pH.

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Section: Resultssupporting

confidence: 86%

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Bock

Lange

2006

Journal of the American Ceramic Society

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“…Normally, the dissociation of the PAA-salt is complete at high pH values (9–10), whereas at lower values it is significantly reduced and therefore gives a poor stabilizing effect. The PAA with ammonia as counter ion increases the pH values up to 9–10 17 , 18 . Powders with very acidic properties, such as silica 17 , 18 , produce lower pH values, which is overcome by incrementing gradually, on an empirical basis, the amount of powder in a finite amount of PAA.…”

Section: Sample Preparation and Experimental Techniquesmentioning

confidence: 99%

“…The PAA with ammonia as counter ion increases the pH values up to 9–10 17 , 18 . Powders with very acidic properties, such as silica 17 , 18 , produce lower pH values, which is overcome by incrementing gradually, on an empirical basis, the amount of powder in a finite amount of PAA. By following the above procedure, the predetermined amount of each powder type, as indicated in Table 1 , is dispersed in its respective suspension.…”

Section: Sample Preparation and Experimental Techniquesmentioning

confidence: 99%

Controlling the optical properties of nanostructured oxide-based polymer films

Angastiniotis

Christopoulos

Petallidou

et al. 2021

Sci Rep

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A bulk scale process is implemented for the production of nanostructured film composites comprising unary or multi-component metal oxide nanoparticles dispersed in a suitable polymer matrix. The as-received nanoparticles, namely Al$$_2$$ 2 O$$_3$$ 3 , SiO$$_2$$ 2 and TiO$$_2$$ 2 and binary combinations, are treated following specific chemical and mechanical processes in order to be suspended at the optimal size and composition. Subsequently, a polymer extrusion technique is employed for the fabrication of each film, while the molten polymer is mixed with the treated metal oxide nanoparticles. Transmission and reflection measurements are performed in order to map the optical properties of the fabricated, nanostructured films in the UV, VIS and IR. The results substantiate the capability of the overall methodology to regulate the optical properties of the films depending on the type of nanoparticle formation which can be adjusted both in size and composition.

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“…[11][12][13][14] Current methods for the automation of the LbL encapsulation process utilize conventional macro-scale reactors which are time consuming non-continuous processes requiring bulky and expensive equipment. 15,16 These reactors not only extend the duration of the LbL process, but also impart problems such as non-uniformity and aggregation of microcapsules requiring further centrifugation, washing and re-suspension steps. Consumption of reagents is also higher in such batch processes which can be an expensive drug in some cases.…”

Section: Introductionmentioning

confidence: 99%

A ‘microfluidic pinball’ for on-chip generation of Layer-by-Layer polyelectrolyte microcapsules

et al. 2011

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Inspired by the game of "pinball" where rolling metal balls are guided by obstacles, here we describe a novel microfluidic technique which utilizes micropillars in a flow channel to continuously generate, encapsulate and guide Layer-by-Layer (LbL) polyelectrolyte microcapsules. Droplet-based microfluidic techniques were exploited to generate oil droplets which were smoothly guided along a row of micropillars to repeatedly travel through three parallel laminar streams consisting of two polymers and a washing solution. Devices were prototyped in PDMS and generated highly monodisperse and stable 45±2 µm sized polyelectrolyte microcapsules. A total of six layers of hydrogen bonded polyelectrolytes (3 bi-layers) were adsorbed on each droplet within <3 minutes and a fluorescent intensity measurement confirmed polymer film deposition. AFM analysis revealed the thickness of each polymer layer to be approx. 2.8 nm. Our design approach not only provides a faster and more efficient alternative to conventional LbL deposition techniques, but also achieves the highest number of polyelectrolyte multilayers (PEMs) reported thus far using microfluidics. Additionally, with our design, a larger number of PEMs can be deposited without adding any extra operational or interfacial complexities (e.g. syringe pumps) which are a necessity in most other designs. Based on the aforementioned advantages of our device, it may be developed into a great tool for drug encapsulation, or to create capsules for biosensing where deposition of thin nanofilms with controlled interfacial properties is highly required.

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A novel processing scheme for core—shell nano composites using controlled polymer adsorption

Cited by 12 publications

References 7 publications

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Controlling the optical properties of nanostructured oxide-based polymer films

A ‘microfluidic pinball’ for on-chip generation of Layer-by-Layer polyelectrolyte microcapsules

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A novel processing scheme for core—shell nano composites using controlled polymer adsorption

Cited by 12 publications

References 7 publications

Effects of CnTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Effects of CnTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Controlling the optical properties of nanostructured oxide-based polymer films

A ‘microfluidic pinball’ for on-chip generation of Layer-by-Layer polyelectrolyte microcapsules

Contact Info

Product

Resources

About

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders

Effects of C_nTAB Chain Length and Concentration on the Rheological Properties of Aqueous Suspensions of Alkylated Alumina Powders