Supramolecular self-assembly can not only lead to a better understanding of biological systems, but also can enable rational building of complex and functional materials. In this report, hierarchical one-dimensional (1D) architectures involving nanotubes, coiled-coil ropelike structures, nanohelices, and nanoribbons are created via lanthanum-cholate supramolecular self-assembly. These sophistic...

Shear relaxation and dynamic density fluctuations are studied within a Rouse model, generalized to include the effects of permanent random crosslinks. We derive an exact correspondence between the static shear viscosity and the resistance of a random resistor network. This relation allows us to compute the static shear viscosity exactly for uncorrelated crosslinks. For more general percolation ...

Coagulation of charged particles was studied using the mean-field Smoluchowski equation. The coagulation equation was generalized for the case of a conserved system of charged particles. It was shown that runaway cluster growth (gelation) solutions exist if the charge-dipole (induced) interaction of clusters is included. When clusters are in thermal equilibrium with the ambient gas, the charge-...

Organo-gels with a series of biscarbamates as gelators were prepared using microwave (MW) heating source as well as conventional heating. Biscarbamates with alkyl side chain lengths varying from C5 to C18 were used, with six solvents having dipole moments ranging from 0.07 to 4.3 D. The minimum gelation concentration and the time required for dissolution were significantly reduced with MW heati...

Microencapsulation has become a common technique in the production of controlled release dosage forms. Many results have been reported, concerning the use of alginate beads as controlled release drug formulations. Alginate has a unique gel-forming property in the presence of multivalent cations, in an aqueous medium. Ibuprofen is an excellent analgesic and antipyretic, non-steroidal anti-inflam...

The first molecule that assembles by ultrasound is described. An association-inert dinuclear Pd complex, anti-1a, which is stabilized by intramolecular pi-stacking interactions, gelatinizes a variety of organic solvents instantly upon brief presonication for a few seconds. This is the first quick, positive, and reversible method for the remote switching of stable sol-gel phases. Uniquely, the r...

We study a chemical gelation model in two dimensions which includes both monomer aggregations and bond fluctuations. Our numerical simulation shows that a sol-gel transition occurs when an initial monomer concentration is above a critical concentration. Fractal aggregates grow until the sol-gel transition occurs. After the gelation, however, bond fluctuations break the fractal structure and an ...

A random mixture of bifunctional and tetrafunctional units is placed on a simple cubic lattice. Permanent bonds between these units are then formed by the random motion of active centres (radicals) resulting in a model for the gelation of polyacrylamide and similar processes. The largest of the clusters formed by this kinetic percolation process is identified with the gel fraction, the ‘mean cl...

The aim of this work was to study the structure formation of yogurt made with cultures containing ropy Lactobacillus delbrueckii ssp. bulgaricus (R), capsule-forming nonropy Streptococcus thermophilus (CNR), and noncapsule-forming nonropy cultures (NCNR). Similar gelation profiles were shown for milk fermented by ropy and nonropy lactic cultures. The gelation point occurred at lower pH values i...