In this feature article, we discuss a series of contributions dealing with the in situ fabrication of supramolecular metallogels (i.e. using low molecular weight ligands and metal ions) that show self-healing properties of the bulk gel phase after complete physical segregation. Most of the advances in this area have taken place during the last three years and are mainly represented by organogel...

Fifteen compounds reported to be inhibitors of gelation or sickling were studied by standard methods. These tests included (1) the determination of the solubility of deoxyhemoglobin S or Csat, (2) evaluation of sickling in whole SS blood at various pO2s, (3) measurement of the oxygen affinity of hemoglobin and blood, and (4) examination of red cell indices and morphology. Among the 4 noncovalen...

Hydrogel matrices are valuable platforms for neuronal tissue engineering. Orienting gel fibers to achieve a directed scaffold is important for effective functional neuronal regeneration. However, current methods are limited and require treatment of gels prior to implantation, ex-vivo, without taking into consideration the pathology in the injured site. We have developed a method to control gel ...

Recent experiments show that networks of stiff biopolymers cross-linked by transient linker proteins exhibit complex stress relaxation, enabling network flow at long times. We present a model for the dynamics controlled by cross-links in such networks. We show that a single microscopic timescale for cross-linker unbinding leads to a broad spectrum of macroscopic relaxation times and a shear mod...

We report on the synthesis, microstructure and mass transport properties of a colloidal hydrogel self-assembled from a mixture of colloidal silica and nontronite clay plates at different particle concentrations. The gel-structure had uniaxial long-range anisotropy caused by alignment of the clay particles in a strong external magnetic field. After gelation the colloidal silica covered the clay ...

Smoluchowski's equation for rapid coagulation is used to describe the kinetics of gelation, in which the coagulation kernel Kij models the bonding mechanism. For different classes of kernels we derive criteria for the occurrence of gelation, and obtain critical exponents in the preand postgelation stage in terms of the model parameters; we calculate bounds on the time of gelation to, and give a...

transition in melts. Although polymeric systems’ technological applications in many different fields have received increasing researcher interest, their nontrivial viscoelastic behavior still doesn’t have a completely satisfying description. Of particular interest is the sol-gel transition, in which a viscous fluid (the sol) transforms into an elastic disordered solid (the gel) by creating in t...

Biodegradable polymers have been widely used as scaffolding materials to regenerate new tissues. To mimic natural extracellular matrix architecture, a novel highly porous structure, which is a three-dimensional interconnected fibrous network with a fiber diameter ranging from 50 to 500 nm, has been created from biodegradable aliphatic polyesters in this work. A porosity as high as 98.5% has bee...

Silica aerogels were prepared via the sol–gel process using tetramethoxysilane (TMOS) as the precursor and polyethylene oxide (PEO) of molecular weights 10,000 and 100,000 to provide a polymeric template for gelation. The experiments included eleven different formulations ranging from 100% 10,000MW PEO to 100% 100,000MW PEO in 10% increments. The total concentration of PEO was kept constant thr...