No abstract

Novel photopolymerized network films based on a polysiloxane matrix containing varied amounts of polyoxyethylene (P3) or perfluorohexylethyl (F) dangling side chains were investigated. For films containing less than 10 wt % P3 and F, the wettability and elastic modulus were similar to those of the photopolymerized network matrix. However, angle-resolved X-ray photoelectron spectroscopy measurements proved that the surface of films with F dangling chains was highly enriched in fluorine depending on both the amount of P3 and F and their relative ratio in the films. The biological performance of the films was evaluated against a new widespread and invasive marine biofoulant, the serpulid Ficopomatus enigmaticus. The diatom Navicula salinicola was also assayed as a conventional model organism for comparison. Films richer in P3 better resisted the settlement and promoted the release of calcified tubeworms of F. enigmaticus.

No abstract

Sol-gel polysiloxane films containing varied amounts of different trialkoxyorganosilanes, carrying hydrophobic perfluoroalkyl (F) and/or hydrophilic polyoxyethylene (P) side chains, were prepared. The effect of the surface-active agents F and P on the film surface properties were investigated by contact angle measurements and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) analysis. In particular, AR-XPS proved that the fluorinated side chains migrated to the film surface depending on both the nominal amount of F and the presence of P in the formulation. Moreover, the films underwent surface chemical modification upon contact with water, as a result of an increase in P chains and a concomitant decrease in F chains at the film surface. The biological performance of the films was evaluated against the serpulid Ficopomatus enigmaticus, a widespread and invasive marine biofoulant, and demonstrated the potential of the amphiphilic films containing P chains as fouling-release coatings in the marine environment.

The traditional use of organic solvents in various branches of industry is being rethought as these compounds very often display high volatility, toxicity and lipophilicity (related to the ability to interact with biological membranes). More recently, developments in the field of Green Chemistry are focusing on the design of more sustainable and cost-effective solvent alternatives like Ionic Liquids (ILs), bio-based solvents and natural deep eutectic solvents (NADESs). The present study aimed at performing an ecotoxicological screening of 15 NADESs using an extensive set of marine and freshwater bioassays, based on different endpoints as the following: immobilization of the crustacean Daphnia magna, growth inhibition of Raphidocelis subcapitata and of Phaeodactylum tricornutum, larval development alterations on the serpulid Ficopomatus enigmaticus and bioluminescence inhibition of Aliivibrio fischeri. What emerged was a general absence of toxicity of all samples. However, both algal assays showed a certain degree of biostimulation, up to over 100% growth increase in respect to controls with 8 out of 15 compounds tested with Raphidocelis subcapitata. Despite NADESs-induced negligible toxicity effects to invertebrates, encouraging their labelling as “sustainable” solvents, the liability of their intentional or accidental release into aquatic systems may represent a serious risk in terms of ecosystem functioning impairments.

No abstract

No abstract

Surface-active amphiphilic diblock copolymers, Si-EFS14 and Si-EFS71, consisting of a poly(dimethyl siloxane) block (degree of polymerisation 11) and a poly(4-(triethyleneglycol monomethyl ether)-2,3,5,6-tetrafluorostyrene) block (average degree of polymerisation 14 and 71) were synthesised by ATRP. Films were prepared by incorporating each copolymer (4 wt%) into a PDMS matrix, which was then condensation cured. Bioassays were performed on the films using two barnacle species, Balanus amphitrite and Balanus improvisus, at different stages of their life cycles. The cyprids of B. improvisus settled on all test surfaces in higher numbers than those of B. amphitrite. However, the juveniles of B. improvisus were more easily removed from the films con-taining the copolymer Si-EFS14 than from those containing the copolymer Si-EFS71. An XPS analysis revealed that the near-surface region of copolymer Si-EFS71 was enriched in oxyethylenic chains and became even more populated by these hydrophilic chains after the films were immersed in water.Dear Axel, Please find enclosed our revised paper. We thank the reviewers for their appreciation of our work and helpful comments. We accepted essentially all the suggestions from Reviewers 2 and 3 and changed the text accordingly; see our changes and answers in red. As for Reviewer 1, let us insist that the main innovation resides in the complementary approach of the work by polymer chemistry, physics, surface science and biology, although individual aspects may not be fully original per se. Therefore, we do believe that the paper is well suited for publication in Polymer to the benefit of the expert in the art and the general reader.The paper is now in a better shape and we look forward to its final acceptance and publication. Warm regards, GiancarloCover Letter Dear Axel, Please find enclosed our revised paper. We thank the reviewers for their appreciation of our work and helpful comments. We accepted essentially all the suggestions from Reviewers 2 and 3 and changed the text accordingly; see our changes and answers in red. As for Reviewer 1, let us insist that the main innovation resides in the complementary approach of the work by polymer chemistry, physics, surface science and biology, although individual aspects may not be fully original per se. Therefore, we do believe that the paper is well suited for publication in Polymer to the benefit of the expert in the art and the general reader.The paper is now in a better shape and we look forward to its final acceptance and publication.