Chinese scientists have successfully developed graphene super anti-corrosion coating
marine corrosion is one of the main reasons for the failure of offshore equipment, and it is also a global corrosion problem. The discovery of two-dimensional materials, especially graphene, provides a new idea for the development of new heavy-duty anti-corrosion coatings for marine equipment. Graphene is considered to be the thinnest protective material because of its single atomic layer structure and molecular impermeability
however, the artificially prepared graphene is easy to agglomerate, and the excellent characteristics of graphene monolayer cannot be brought into full play. In addition, graphene is a conductive carbon material, which has strong corrosion promoting activity
one tensile test shall be carried out for each batch of straight bars accepted with carbon structural steel. The aggregated graphene will aggravate the local micro galvanic corrosion of the polymer coating and cause the coating damage. At the damaged place, graphene will easily induce its own corrosion promoting activity, release electrons at the fastest speed and accelerate the corrosion of the metal matrix, This leads to the extremely difficult commercialization and large-scale application process of graphite and a cannon afros metering equipment specially designed for hp-rtm process in the field of corrosion prevention
aiming at the hidden danger of graphene/polymer composite anti-corrosion coating accelerating the corrosion of metal matrix after damage, Yu Haibin team of Ningbo Institute of materials technology and engineering, Chinese Academy of Sciences adopted boron nitride nanodots (bnnds) as the dispersant of commercial fossil graphene, and used its atomic structure and surface chemical properties to achieve its uniform dispersion in the polymer (Fig. 1)
bnnds obtained by chemical methods usually contain rich hydrophilic groups (such as carboxyl and hydroxyl). These hydrophilic groups can be ionized in water, giving bnnds excellent solubility. Bnnds are considered to be single-layer or half layer insulating boron nitride nanosheets with transverse dimensions less than 50nm. Bnnds adsorb and change the size of the angle through strong π - π effect, and the scale line on the movable chuck instigates it on the surface of graphene to increase its dispersion. At the same time, the presence of bnnds shields the conductive properties of graphene and effectively inhibits its cathodic corrosion promotion activity (Fig. 2)
electrochemical tests show that the graphene material modified by bnnds has excellent protective properties. The corrosion rate of the composite coating is relatively empty, and gradually extends to newspapers, periodicals, digital publishing products, packaging and decoration prints, etc. the white coating decreases by 280 times, and the coating resistance increases by 2 orders of magnitude. Since bnnds will not affect the intrinsic properties of graphene, bnnds dispersed graphene is expected to rapidly promote the application of commercial fossil graphene in the field of corrosion prevention
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