Marine biofouling profoundly influences marine industries and activities. It slows the speed and increases the fuel consumption of ships, corrodes the offshore platforms and blocks the seawater pipelines. The most effective and economic antifouling approach is using coatings. Fouling release coatings (FRCs) with low surface free energy and high elasticity weakly adhere to marine organisms so they can be readily removed by the water shear force. FRCs have received increasing interest because they are biocide-free and hence eco-friendly. Yet, traditional silicone based FRCs have weak adhesion to substrate, low mechanical strength and low fouling resistance, limiting their applications. In recent years, many attempts have been made to improve their mechanical properties and fouling resistance. The review deals with the progress in construction of high-performance silicone based fouling release surfaces.
Marine biofouling is a global problem today. High efficiency and eco-friendly antifouling systems are in pressing need. In recent years, we have proposed the concept of dynamic surface antifouling (DSA). That is, a continuously changing surface can effectively prevent marine fouling organisms from landing and adhesion. Based on this strategy, we developed coatings with dynamic surfaces by using degradable polymers including polyester-polyurethane, modified polyester and poly(ester-co-acrylate). They exhibit tunable renewability, and excellent antifouling and mechanical performance. Moreover, the polymers can serve as carrier and controlled release systems of antifoulants so that they have long service life. This paper reviews the progress and trends in marine anti-biofouling, and presents the mechanism and systems of DSA.
The research on advanced functional polymers is being driven by the fast-growing demand for new functional materials that can be used in revolutionary technologies. Polymers can be endowed with functions by using certain special preparation methods or by introducing functional groups or fillers into materials. These functions are either intrinsically possessed by materials or actuated by external stimuli. In this review, we present an overview of the recent developments made in the research hotspots of functional polymers, encompassing polymerization methodologies, luminescent polymers, photovoltaic polymers, other electronic and optical polymers (including low-k polyimides and second-order nonlinear optical polymers), biorelated polymers (particularly those for biomedical applications), supramolecular polymers, stimuli-responsive polymers, shape-memory polymers, separation polymer membranes, energy storage polymers, and covalent organic framework polymers. The concepts, design strategies at the molecular level, preparation methods, classifications, properties, potential applications, and recent progress made in such polymers are summarized. Challenges and future perspectives of each type of functional polymers are also addressed, including research efforts regarding the design and fabrication of functional polymers for serving the increasing demand for new materials.
Marine biofouling is one of the most challenging problems today. Silicone polymer based coatings with a low surface energy and elastic modulus can effectively inhibit or release biofouling. However, their non-repairable properties and poor antifouling ability under static conditions limit their applications. Here, we report a self-repairing coating consisting of poly(dimethylsiloxane) based polyurea (PDMS-PUa) and a small amount of organic antifoulant (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) (DCOIT). The coating can completely recover its mechanical properties after damage either in air or artificial seawater at room temperature. Such recovery can be accelerated at a higher temperature. Moreover, the release rate of DCOIT is almost constant and can be regulated by its concentration. Six-month marine field tests demonstrate that the system has a good antifouling/fouling release performance even under static conditions.