The synthesis of a series of u-hydroxyfatty acid (u-OHFA) monomers and their methyl ester derivatives (Me-u-OHFA) from mono-unsaturated fatty acids and alcohols via ozonolysis-reduction/crossmetathesis reactions is described. Melt polycondensation of the monomers yielded thermoplastic poly(u-hydroxyfatty acid)s [-(CH 2 ) n -COO-] x with medium (n ¼ 8 and 12) and long (n ¼ 17) repeating monomer units. The u-OHFAs and Me-u-OHFAs were all obtained in good yield ($80%) and purity ($97%) as established by 1 H NMR, Fourier Transform infra-red spectroscopy (FT-IR), mass spectroscopy (ESI-MS) and high performance liquid chromatography (HPLC) analyses. The average molecular size (M n ) and distribution (PDI) of the poly(u-hydroxyfatty acid)s (P(u-OHFA)s) and poly(u-hydroxyfatty ester)s (P(Me-u-OHFA)s) as determined by GPC varied with organo-metallic Ti(IV) isopropoxide [Ti(OiPr) 4 ] polycondensation catalyst amount, reaction time and temperature. An optimization of the polymerization process provided P(u-OHFA)s and P(Me-u-OHFA)s with M n and PDI values desirable for high end applications. Co-polymerization of the long chain (n ¼ 12) and medium chain (n ¼ 8) Me-u-OHFAs by melt polycondensation yielded poly(u-hydroxy tridecanoate/u-hydroxy nonanoate) random co-polyesters (M n ¼ 11 000-18 500 g mol À1 ) with varying molar compositions.

Novel biodegradable thermoplastic poly(ω‐hydroxyfatty acid) polyesters that are functional equivalents of fossil‐fuel based polyethylene are synthesised from bio based vegetable oil feedstock.

In this article, polyethylene glycol-acrylamide (PEG-AAm) hydrogels were experimentally prepared with a matrix structure and their swelling behaviors were tested. Different amounts of polyethylene glycol, acrylic acid, and acrylamide were added, and an optimum case was discovered. Effect of some parameters on the swelling was then investigated. A dynamic model based on the Maxwell-Stefan equation, Nernst-Planck equation, and Donnan theory was developed to consider the swelling behavior of hydrogels. These equations were applied to model the buffer diffusion inside the hydrogels in the swelling process. COMSOL software was also applied to simulate the swelling behavior in the hydrogels. The results showed that the data obtained from the modeling were in good agreement with the experimental data (the deviation value was around 16%). Further, COMSOL was able to simulate water diffusion process in the hydrogels, properly.

The synthesis and characterisation of a novel dansylated magnetic nanostructure, namely Fe3O4@SiO2-PEG-DnS, is reported here. Investigations of its fluorescent properties showed that the presence of the PEG moiety significantly enhanced the fluorescent intensity of the nanostructure when compared to both the free dansyl fluorophore and a nanostructure that contained no PEG spacer between the core and the attached dansyl group. The addition of zinc (Zn 2+) ions to the aqueous suspension of Fe3O4@SiO2-PEG-DnS led to a 12.5-fold decrease in intensity. The quenching was selective to only Zn 2+. No interference was observed by other examined metal cations, including cadmium (Cd 2+). A very low detection limit of 6.00 nM in relation to zinc ions was demonstrated. In addition, the newly developed magnetic nanostructured chemosensor was found to be highly stable, reusable and recoverable.

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