The phase behavior of colloids that interact via competing interactions - short-range attraction and long-range repulsion - is studied by computer simulation. In particular, for a fixed strength and range of repulsion, the effect of the strength of an attractive interaction (ε) on the phase behavior is investigated at various colloid densities (ρ). A thermodynamically stable equilibrium colloid...

A new class of fluorescent organogelators, pyrene-containing poly(arylene ether sulfone)s, showed two fluorescence switching modes in different gelation solvents. The THF gel exhibited excimer emission due to dimerization of the pyrene groups. In contrast, excimer emission was quenched after gelation in MC because of stacking among the pyrene groups.

Instantaneous gelation in the addition model with superlinear rate coe cients is investigated. The conjectured post-gelation solution is shown to arise naturally as the limit of solutions to some nite approximations as the number of equations grows to in nity. Non-existence of continuous solutions to the addition model is also established in that case.

A new gelator was discovered by identifying molecular scaffolds exhibiting 1D intermolecular interactions in the solid-state and synthesizing derivatives. Gelation can be triggered by adding Hg(OAc)(2) to a precursor molecule. The in situ gelation is selective for Hg(2+) over other metals.

A novel chiral coordination polymeric gel based on an amino acid derived symmetrical ligand, specific base, and Zn(2+) has been described. Zn(2+) induced conformational reorganization in the ligand leads to gelation via J-aggregated helical fibres. The vital role played by π-π stacking in gelation has been monitored by fluorescence and NMR spectroscopy.

It was found that CO2 could induce the gelation of Pluronic aqueous solutions, during which the microstructure of the solution transforms from randomly dispersed spherical micelles to cubic close packed micelles. The gelation switched by compressed CO2 has many advantages and can be applied in the synthesis of porous materials.

The present work investigated the preparation of biodegradable beads with alginate polymer by ionotropic gelation method to improve the control release properties of the antibiotic rifampicin. Ionotropic gelation method was applied to prepare beads using calcium chloride (CaCl2) as cationic component and alginate as an anionic component. In this method, adding 0.5% w/v polyvinyl alcohol (PVA) t...

Among the methods available to reduce water production, injecting a gelling system composed of a polymer and a crosslinker has been widely used. In this work, a hydrogel was prepared by crosslinking of an aqueous solution containing hexamethylenetetramine (HMTA) as crosslinker, hydrochloric acid (HCl) as an activator, and the co-polymer of 2-acrylamido-2methyl-propanesulfonic-acid sodium salt (...

We attempt a classification of different colloidal gels based on colloidcolloid interactions. We discriminate primarily between non-equilibrium and equilibrium routes to gelation, the former case being slaved to thermodynamic phase separation while the latter is individuated in the framework of competing interactions and of patchy colloids. Emphasis is put on recent numerical simulations of col...