Reversible, shear-induced gelation of semi-dilute aqueous colloidal dispersions consisting of monodisperse discoid particles (Laponite) and weakly adsorbing polymer (polyethylene oxide) is studied through a combination of small angle neutron scattering and oscillatory shear. When shaken the samples undergo a dramatic transition from a low viscosity fluid to a self-supporting, turbid gel. This c...

Thin films of molecular gels formed in a confined space have potential applications in transdermal delivery, artificial skin, molecular electronics, etc. The microstructures and properties of thin gel films can be significantly different from those of their bulk counterparts. However, so far a comprehensive understanding of the effects of spatial confinement on the molecular gelation kinetics, ...

The effects of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), on the gelation of methylcellulose (MC) in aqueous solutions have been investigated by micro differential scanning calorimetry (micro DSC) and rheology. Methylcellulose had a weight average molecular weight of 310,000 and a degree of substitution of 1.8. The concentration of MC was kept at 0.5 wt % (0.016 mM) and 1 wt ...

Structural characterization of a hydrogel consisting of an oligomeric electrolyte, poly[pyridinium-1,4-diyliminocarbonyl-1,4-phenylenemethylene chloride] (1-Cl) as an ionic gelator was carried out by static and dynamic light scattering (SLS/DLS) and small-angle neutron scattering (SANS) techniques. All the measurements were performed by changing the concentration and temperature. We have succes...

Mature oilfields usually encounter the problem of high watercut. It is practical to use chemical methods for water-shutoff in production wells, however conventional water-shutoff agents have problems of long gelation time, low gel strength, and poor stability under low temperature and high salinity conditions. In this work a novel polymer gel for low temperature and high salinity reservoirs was...

Organogels with perylene derivatives and phthalocyanines reported in the literature so far involve self-assembly promoted by hydrogen bonds, in addition to aromatic and van der Waals interactions. Although the self assembly of these types of molecules without a hydrogen bonding group in the structure occurs in solution or during crystallization, the gelation studies reported so far incorporated...