Topics

Thermodynamics of Hierarchical Aggregation in Pigment Dispersions.

08:00 EDT 12th September 2019 | BioPortfolio

Summary of "Thermodynamics of Hierarchical Aggregation in Pigment Dispersions."

Many commercially and industrially important materials aggregate to form nanoscale mass-fractal structures. Unlike hard aggregates such as fumed silica, aqueous pigment-based inks consist of weakly bound nanoparticles stabilized by a surfactant. These soft aggregates can easily break apart and re-form balancing mixing energy and the reduction in surface energy with clustering or aggregation. Rapid thermal motion of small elemental crystallites lead to dense clusters or primary particles. The larger primary particles have slower thermal motion and aggregate into ramified mass fractals to form a dual level hierarchical structure. It is proposed that the hierarchical structure relies on subtle and competitive equilibria between the different hierarchical structural levels. A new hierarchical thermodynamics model by Vogtt is used. Pigment yellow 14 and pigment blue 15:3 as surfactant stabilized aqueous dispersions were employed to explore the thermodynamics of nanoparticle hierarchical equilibria. It was demonstrated that reversible nanoparticle aggregation can be described solely by the change in free energy of dissociation and the change in free energy of mixing in the context of a subunit being removed from a cluster. The hierarchical thermodynamics is dominated by the solubility of the dispersing surfactant. At the cloud point for the surfactant, primary particles approach the size of an elemental particle and the degree of aggregation becomes very large. The results indicate that subtle and reproducible control over pigment hierarchical structure and size is possible through thermal equilibration, manipulation of the surfactant properties and elemental crystallite size.

Affiliation

Journal Details

This article was published in the following journal.

Name: Langmuir : the ACS journal of surfaces and colloids
ISSN: 1520-5827
Pages:

Links

DeepDyve research library

PubMed Articles [2670 Associated PubMed Articles listed on BioPortfolio]

Statistical thermodynamics of casein aggregation: Effects of salts and water.

Salts, when added to milk, profoundly influence casein aggregation. Even though this well-known phenomenon has been widely exploited, there are still many unanswered questions. How do salts affect cas...

Aggregation Behavior of Nanoparticle-Peptide Systems Affects Autophagy.

The aggregation of nanoparticle colloidal dispersions in complex biological environments changes the nanoparticle properties, such as size and surface area, thus affecting the interaction of nanoparti...

A new approach for the achievement of stable aqueous dispersions of carbon nanotubes.

A novel methodology to prepare stable aqueous dispersions of raw single- and multi-walled carbon nanotubes is reported, based on dispersions previously prepared in tetrahydrofuran containing a phenol ...

Hierarchical multi-view aggregation network for sensor-based human activity recognition.

Sensor-based human activity recognition aims at detecting various physical activities performed by people with ubiquitous sensors. Different from existing deep learning-based method which mainly extra...

Reversible Aggregation of Chlorophyll Derivative Induced by Phase Transition of Lipid Bilayers.

Controlling the supramolecular organization of pigment molecules will provide innovative materials that exhibit variable optical properties. In nature, photosynthetic systems employ chlorophyllous sup...

Clinical Trials [310 Associated Clinical Trials listed on BioPortfolio]

Efficacy and Tolerance of D-pigment Versus Moisturizer in Hands' Lentigo Lesions With or Without Laser Therapy

Pierre Fabre Dermo-Cosmétique has commercialized a cosmetic product (D-pigment rich texture) for treatment of hyperpigmentation. The aim of this study is to evaluate the efficacy of D-pig...

Aflibercept in Patients With Pigment Epithelial Detachments (PED)

Uncontrolled single site non randomized non interventional study to determine the safety and efficacy of intravitreal injections of Aflibercept in patients with recent vision loss due to r...

Using the Hierarchical Cluster Method for Foot Deformities

The aim of this study is to analyze all of the variables with a Hierarchical Cluster Analysis of Multivariate Statistical Methods to obtain more sensitive results, and also to add a new di...

Intravitreal Ranibizumab in Retinal Pigment Epithelial Detachments

The purpose of this study is to demonstrate the efficacy of ranibizumab in patients with retinal pigment epithelial detachment secondary to age-related macular degeneration (AMD).

Study to Determine Racial and Gender Differences in Platelet Aggregation

The purpose of this study is to see if there is a racial and/or gender difference in platelet aggregation.

Medical and Biotech [MESH] Definitions

The formation of clumps of RED BLOOD CELLS under low or non-flow conditions, resulting from the attraction forces between the red blood cells. The cells adhere to each other in rouleaux aggregates. Slight mechanical force, such as occurs in the circulation, is enough to disperse these aggregates. Stronger or weaker than normal aggregation may result from a variety of effects in the ERYTHROCYTE MEMBRANE or in BLOOD PLASMA. The degree of aggregation is affected by ERYTHROCYTE DEFORMABILITY, erythrocyte membrane sialylation, masking of negative surface charge by plasma proteins, etc. BLOOD VISCOSITY and the ERYTHROCYTE SEDIMENTATION RATE are affected by the amount of erythrocyte aggregation and are parameters used to measure the aggregation.

Colloid or hyaline bodies lying beneath the retinal pigment epithelium. They may occur either secondary to changes in the choroid that affect the pigment epithelium or as an autosomal dominant disorder of the retinal pigment epithelium.

Chromatophores (large pigment cells of fish, amphibia, reptiles and many invertebrates) which contain melanin. Short term color changes are brought about by an active redistribution of the melanophores pigment containing organelles (MELANOSOMES). Mammals do not have melanophores; however they have retained smaller pigment cells known as MELANOCYTES.

The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.

Chemically stimulated aggregation of cell surface receptors, which potentiates the action of the effector cell.

Quick Search


DeepDyve research library

Searches Linking to this Article