For the first time, composite coatings based on poly(dimethylsiloxane-block-ε-caprolactone) copolymer and tricalcium phosphate were obtained on stainless steel plates by using the electrophoretic deposition technique. The effect of different deposition times on the final characteristics of the resulting coatings was also studied. Block copolymers were obtained through a combination of anionic and ring-opening polymerization, with good homogeneity and chemical composition (Ð < 1.3 and wPCL = 0.39). The composites obtained at different electrophoretic deposition times revealed a linear dependence between the deposited weight and time during assays. When immersing in simulated body fluid, a higher amount of residual solids ( ∼ 20 %) were observed by thermogravimetric analysis after 7 days of immersion. Scanning electron microscopy micrographs revealed a porous microstructure over the metallic substrate and the absence of micro-cracks, and X-ray diffraction patterns exhibited diffraction peaks associated with a hydroxyapatite layer. Finally, energy-dispersive X-ray analysis revealed values of the Ca/P ratio between 1.40 and 1.50 in samples, which are closer to the stoichiometric hydroxyapatite values reported in hard tissues. The results obtained in this article confirm the usefulness of poly(dimethylsiloxane-block-ε-caprolactone) copolymer and cheaper tricalcium phosphate as precursors of compact and homogenous coatings obtained by electrophoretic deposition, which yields useful substrates for hydroxyapatite growth.

The use of bentonite for organic dyes removal in the water system is an economical and highly efficient alternative against the usually applied purification methods. However, during the post‐treatment stage bentonite swells and forms highly stable colloidal suspensions, being difficult to separate from the aqueous system. In this work, calcium alginate hydrogels beads with 5 and 10% w/w of bentonite are synthetized and their capacity to adsorb methylene blue, as model dye, from aqueous media is evaluated. Structure and mechanical properties of hydrogels beads are determined, showing that hydrogels beads with bentonite present higher viscosity and hardness. Regarding methylene blue adsorption capacity, the effect the contact time (0–32 h) and the initial cadmium ion concentration (0.2–3.0 mg L−1) are studied employing hydrogel beads. The equilibrium adsorption time is reached at 300 min for all studied hydrogels and experimental data are fitted well with a pseudo‐second order kinetic model. As conclusion, alginate/bentonite hydrogel beads are accepted as a promising candidate to remove methylene blue dye from aqueous solutions.

Branched copolymers are a special class of polymeric materials in which are reflected the combined effects of polymer segments and architectural constraints of the branched architecture. In this work, three‐armed graft copolymers, poly (hydroxyethyl methacrylate‐graft‐poly(caprolactone), [P(HEMA‐g‐PCL)]3, are synthesized by combination of reversible addition‐fragmentation chain‐transfer (RAFT) and ring opening polymerization (ROP) mechanisms in a one‐pot/one‐step protocol. The resulting macromolecules are characterized by 1H Nuclear Magnetic Resonance (NMR), size exclusion chromatography (SEC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The preliminary results indicate the success of the methodology and are in agreement with literature reports. In addition, DSC isothermal crystallization are performed, and Avrami's theory is employed in order to obtain kinetics parameters of interest, such as the half‐life for the crystallization process (t1/2), the bulk crystallization constant (k), and the Avrami's exponent (n). Thermal analysis evidences a noticeable reduction in the melting temperature compared with linear PCL homopolymer. However, the presence of branches does not modify the values of the maximum degradation temperatures significantly. Finally, the synthesized copolymers adopt a two‐dimensional crystallization type (disk and cylindrical).