Systems, methods and apparatuses are provided for the reduction of hydrodynamic frictional drag. These systems, methods and apparatuses can include a vessel surface having an external layer and a plurality of dimples, wherein the external layer comprises a hydrophilic material, and wherein each of the dimples includes an inner surface having a superhydrophobic coating. The dimples can be configured to maintain an air-water interface as one or more fluids flow over the vessel surface. In some embodiments, a pressure reservoir can be coupled with the dimples, and can include an acoustic speaker to vibrate the air-water interface.

Methods of protecting a submerged surface from biofouling animal organisms include applying a first biologically active inner polymer layer on a surface, impregnated with at least one first biologically active agent that kills a juvenile stage of a biofouling animal organism. A second biologically active outer polymer layer is applied on the first biologically active inner polymer layer, impregnated with at least one second biologically active agent that inhibits a larval stage of the biofouling animal organism from attaching to the second biologically active outer polymer layer. The second biologically active outer polymer layer includes a friction-reducing additive selected from the group consisting of silicone powder, PTFE powder, molybdenum disulfide powder, graphene nano-platelets, graphene oxide, and fluorinated graphene powder.

A method for manufacturing an organism adhesion reduction paint includes a first process of gelling a raw material composition that includes polyvinyl alcohol and at least one of a hydroxyl group-containing inorganic compound or an inorganic oxide; a second process of drying and subsequently pulverizing a resulting product in the first process to thereby obtain a composite gel fine powder; and a third process of adding the composite gel fine powder to a main component of a two-component urethane paint and stirring, to thereby prepare a main component of the organism adhesion reduction paint, and also adding a curing agent immediately before use.

A water-soluble composition includes reducible copper ions or copper nanoparticles complexed with a reactive polymer. The reactive polymer can be crosslinked using suitable irradiation to provide copper-containing water-insoluble complexes. The water-soluble composition can be used to provide various articles and electrically-conductive materials that can be assembled in electronic devices. The reactive polymer has greater than 1 mol % of recurring units comprising sulfonic acid or sulfonate groups, at least 5 mol % of recurring units comprising a pendant group capable of crosslinking via [2+2] photocycloaddition, and optionally at least 1 mol % of recurring units comprising a pendant amide, amine, hydroxyl, lactam, phosphonic acid, or carboxylic acid group.

A controlled-release material sensitive and response to fouling organisms for an antifouling agent includes an encapsulating precursor and a crosslinking agent. A hyaluronic acid/polyL-lysine nano-shell controlled-release material is prepared by an alternating layer-by-layer self-assembly of hyaluronic acid and poly-L-lysine, and a polypropylene ammonium chloride/poly-L-glycine nano-shell controlled-release material is prepared by an alternating layer-by-layer sell-assembly of polypropylene ammonium chloride and poly-L-glycine. The crosslinking agent is composed of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxythiosuccinimide. Based on the specific catalytic hydrolysis characteristic of fouling organism extracellular proteases on the controlled-release material, the purpose of adjusting the release of antifouling agents adaptively with the change of fouling organisms in off-season/peak-season can be achieved, prolonging the service life of the antifouling coatings.

A composite resin comprising silver nanoparticles and a polymer where the silver nanoparticles are formed by reduction of silver ions by the functional groups of the polymer without the addition or application of an external reducing agent. The composite e resin has a low silver leach rate. The composite resin may be used as a surface coating, particularly an antimicrobial or antifouling surface coating.

The present invention relates to a high-intensity ultraviolet light emitting diodes (6) (UV-LED) device (1) for preventing biofouling formation in a system for subsea operation of a target fluid. Further, the present invention discloses such device for coupling or integration into a subsea treatment system and to a process using such device.

The present application discloses methods for preparing superhydrophobic nano-microscale patterned films, films pre-pared from such methods and uses of such films as superhydrophobic coatings. The superhydrophobic nano- microscale patterned films comprise high aspect ratio nanoparticles such as boron nitride nanotubes (BNNTs) and/or carbon nanotubes (CNTs).

The invention relates generally to liquid-repellent coatings, and in particular, to porous liquid-repellent coatings, a method of preparing the porous liquid-repellent coatings, and a method of characterizing a porous surface for the liquid-repellent coatings. The invention further relates to a porous liquid-repellent coating comprising a porous layer of a transition metal oxide and/or hydroxide and a layer of a liquid-repellent compound deposited onto the porous layer of the transition metal oxide and/or hydroxide, wherein the porous layer of the transition metal oxide and/or hydroxide is comprised of a plurality of surface pores of varying angles with an average angle that is re-entrant.

A method for applying a coating to a surface includes the step of providing a reaction mixture comprising a silicon alkoxide and an alcohol. A reaction limiting amount of water is added. The silicon alkoxides and water are allowed to react to form silica precursor particles during an initial reaction period. A coating precursor composition is prepared by adding an acid soluble in the alcohol to the reaction mixture during a second reaction period after the initial reaction period. The precursor silica particles grow to form silica nanofeatures having a major dimension that is larger than a major dimension of the silica precursor particles. The coating precursor composition is applied to a surface, and the alcohol and water are allowed to evaporate and the silica nanofeatures to adhere to the surface and form a nanostructured layer on the surface. A coating precursor composition and a coated article are also disclosed.