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The in situ polymerization of monomers to form a second network within a preexisting network (first network) is a facile and effective strategy to fabricate semi-interpenetrating (semi-IPN) hydrogels with enhanced mechanical strength; while to comprehend the effects of the first polymer network on the polymerization process of the second network is still a challenging project. This paper introduces a simple method of employing dynamic rheological measurement loops to monitor the real time progress of the in situ polymerized acrylamide (AAm) in a chitosan (CS) solution towards the formation of a semi-IPN hydrogel. To identify the effects of the preexisting network on the polymerization gelation process, the concept “Effective Conversion Ratio (ECR)” is introduced to evaluate the first network effects on the requirement for the polymerized conversion ratio of the second network to form a critical gel. The rheological properties before gel point, at gel point, and at post-gel stage are discussed via the obtained real time data, respectively. The experimental results have proved the suitability of utilizing dynamic rheology to obtain the real time details of the semi-IPN gel fabrication process.

This paper introduces a tripeptide (β-Asp-Phe-Phe, abbreviation β-AspFF) which can self-assemble into long nanofibrils in toluene solvent and further entangle to organogels. The nanofibrils of β-AspFF can serves as ligands to incorporate with Co(II) in the organogels. After being re-immersed into HFIP-H2O mixed solution (Volume Ratio, 1:1), the β-AspFF-Co(II) xerogel exhibited decent oxygen binding properties. Impressively, in comparing with β-AspFF-Co(II) complex, the β-AspFF-Co(II) xerogel proved to be a higher efficient catalyst for catalyzing cyclohexene oxidation reaction. We therefore suppose that the porous and nanofibrils structure of the xerogel plays a key role to improve the catalytic behavior of β-AspFF-Co(II) complex.

A series of small molecular weight organogelators have been synthesized and studied. One as prepared organogel, named BDOT (n = 10) has exhibited excellent adsorption rate (97%) toward high concentrated mercury ions (0.01 M) from aqueous solution. The gelator itself can also serve as in situ colorimetric chemo sensor of Hg2+ hereinto.