Investigating the anti-bioadhesion properties of short, medium chain length, and amphiphilic polyhydroxyalkanoate films.

Silicone materials are widely used in fouling release coatings, but developing eco-friendly protection via biosourced coatings, such as polyhydroxyalcanoates (PHA) presents a major challenge. Anti-bioadhesion properties of medium chain length PHA and short chain length PHA films are studied and compared with a reference Polydimethylsiloxane coating. The results highlight the best capability of the soft and low-roughness PHA-mcl films to resist bacteria or diatoms adsorption as compared to neat PDMS and PHBHV coatings. These parameters are insufficient to explain all the results and other properties related to PHA crystallinity are discussed. Moreover, the addition of a low amount of PEG copolymers within the coatings, to create amphiphilic coatings, boosts their anti-adhesive properties. This work reveals the importance of the physical or chemical ambiguity of surfaces in their anti-adhesive effectiveness and highlights the potential of PHA-mcl film to resist the primary adhesion of microorganisms.

Insight into the Alcohol-Free Ring-Opening Polymerization of TMC Catalyzed by TBD.

We report herein a study on the alcohol-free, ring-opening polymerization of trimethylene carbonate (TMC) in THF, catalyzed by 1,5,7-triazabicyclo [4.4.0] ec-5-ene (TBD) with ratios nTBD/nTMC ranging between 1/20 and 1/400. In all cases, the reaction proceeds very rapidly, even faster than in the presence of alcohol initiators, and provides PTMC with molecular weights up to Mn = 34,000 g mol-1. Characterization of the obtained PTMC samples by MALDI-TOF mass spectrometry, triple detection size exclusion chromatography and 1H NMR spectroscopy reveals the presence of both linear and cyclic polymer chains.

Non-Leachable Hydrophilic Additives for Amphiphilic Coatings.

Amphiphilic surfaces are particularly effective at inhibiting the adhesion of microorganisms (bacteria, cells, microalgae, etc.) in liquid media. The aim of this study is to determine the best hydrophilic linker to promote bonding between poly(ethylene glycol) (PEG) as a hydrophilic additive and poly(dimethyl siloxane) (PDMS) as the hydrophobic matrix. Various parameters have been studied (molecular weight, linker type, and polymer end-group), as well as the efficiency of the linking, the capacity of PEG to access to the surface of the film, and overall film homogeneity. According to the results, a PDMS linker paired with a PEG moiety allows for compatibilization of the compounds during cross-linking. This compatibilization seems to provide a good bonding with the matrix and a good surface access to the hydrophilic moiety. Therefore, this structure comprising a linking function attached to the PDMS⁻PEG copolymer has high potential as a non-releasable additive for amphiphilic coating applications.

Synthesis and self-assembly of carbamoylmethylphosphonate acrylamide-based diblock copolymers: new valuable thermosensitive materials.

We report the synthesis by RAFT polymerization of well-defined diblock copolymers bearing carbamoylmethylphosphonate moieties which proved to sorb gadolinium. These poly(diethyl-6-(acrylamido)hexylcarbamoylmethylphosphonate-b-acrylic acid) (P(CPAAm6C-b-AA)) copolymers were able to self-assemble as a function of temperature, above their cloud point value.