نتایج جستجو برای: external gelation

تعداد نتایج: 193811  

2015
Lei Hu Yang Zhang Olof Ramström

An organogelator was produced and identified from a dynamic imine system, resolved and amplified by selective gelation. The formation of the organogel was monitored in situ by (1)H NMR, showing the existence of multiple reversible reactions operating simultaneously, and the redistribution of the involved species during gelation. The formed organogelator proved effective with a range of organic ...

Journal: :Physical review letters 2013
R E Baumer M J Demkowicz

We use molecular dynamics simulations to show that glass transition in a model phase separating amorphous alloy, Cu(50)Nb(50), occurs by gelation. At the glass transition, a mechanically stiff, percolating network of atoms with icosahedral local packing forms at the interfaces between compositionally enriched regions. This low-energy network halts coarsening of the phase-separated structure and...

2009
Filipe E. Antunes Luigi Gentile Lorena Tavano Cesare Oliviero Rossi

Some systems show high miscibility in water at low temperatures while they phase separate at high temperatures. Before the macroscopic phase separation there is a strong turbidity, defined as clouding [1, 2]. At certain circumstances, namely above a critical concentration, the polymer system stays turbid with a gel-like appearance, without any macroscopic phase separation [3]. Gels defined in t...

Journal: :Chemistry, an Asian journal 2011
Pathik Sahoo D Krishna Kumar Srinivasa R Raghavan Parthasarathi Dastidar

Easy access to a class of chiral gelators has been achieved by exploiting primary ammonium monocarboxylate (PAM), a supramolecular synthon. A combinatorial library comprising of 16 salts, derived from 5 L-amino acid methyl esters and 4 cinnamic acid derivatives, has been prepared and scanned for gelation. Remarkably, 14 out of 16 salts prepared (87.5 % of the salts) show moderate to good gelati...

Journal: :Science 1987
A Mozzarelli J Hofrichter W A Eaton

A laser photolysis technique has been developed to assess the quantitative significance of the delay time of hemoglobin S gelation to the pathophysiology of sickle cell disease. Changes in the saturation of hemoglobin S with carbon monoxide produced by varying the intensity of a photolytic laser beam were used to simulate changes in the saturation of oxyhemoglobin S produced by variations in ox...

Journal: :Soft matter 2015
Nick Koumakis Esmaeel Moghimi Rut Besseling Wilson C K Poon John F Brady George Petekidis

Using a powerful combination of experiments and simulations we demonstrate how the microstructure and its time evolution are linked with mechanical properties in a frustrated, out-of-equilibrium, particle gel under shear. An intermediate volume fraction colloid-polymer gel is used as a model system, allowing quantification of the interplay between interparticle attractions and shear forces. Rhe...

2010
Sebastian Seiffert David A. Weitz

We fabricate thermo-responsive polymer microgels by combining microfluidic pre-gel emulsification with polymer-analogous gelation. This separates the microgel formation from the polymer synthesis; it combines highly controlled microfluidic templating with the great flexibility of preparative polymer chemistry, allowing each to be controlled independently. We produce monodisperse pre-gel droplet...

2010
Andreea Pasc Firmin Obounou Akong Sedat Cosgun Christine Gérardin

Despite the continuous interest in organogels and hydrogels of low molecular weight gelators (LMWG), establishing the relationship between the molecular structure and the gelation mechanism is still a challenge. In this paper our interest focuses on the consequences of slight molecular modifications on the self-assembling behaviour of β-Ala vs Gly-Gly-based hydrogelators. Previously, in our gro...

Journal: :Journal of agricultural and food chemistry 2012
Yi Liu Vishal Javvaji Srinivasa R Raghavan William E Bentley Gregory F Payne

This paper reports a simple, rapid, and sugar-selective method to induce gelation from glucose-containing samples. This method employs glucose oxidase (GOx) to selectively "recognize" and oxidize glucose to generate gluconic acid, which acts to solubilize calcium carbonate and release calcium ions. The release of calcium ions triggers gelation of the calcium-responsive polysaccharide alginate t...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2003
E Ben-Naim P L Krapivsky

We study a class of growth processes in which clusters evolve via exchange of particles. We show that depending on the rate of exchange there are three possibilities: (I) Growth-clusters grow indefinitely, (II) gelation-all mass is transformed into an infinite gel in a finite time, and (III) instant gelation. In regimes I and II, the cluster size distribution attains a self-similar form. The la...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید