Thermally Conductive Anticorrosive Epoxy Nanocomposites with Tannic Acid-Modified Boron Nitride Nanosheets

Abstract

Boron nitride nanosheets (BNNSs) were synthesized by the classical chemical vapor deposition (CVD) method and modified by tannic acid (TA) (named as M-BNNSs). M-BNNSs have greatly improved the thermal conductivity (0.45 W/(m·K)) and mechanical tensile strength (15.10 MPa) of epoxy resin (EP). More importantly, the EP composite coating with an appropriate amount of M-BNNS not only has an excellent anticorrosion effect (the I corr of 10%M-BNNS@EP is 8.053 × 10–7 A/cm2 after immersed in 3.5 wt % NaCl solution for 30 min) on the metal substrates but also has a good anticorrosion stability. The impedance modulus (|Z|0.01) of the 10%M-BNNS@EP coating is higher than that of the neat EP coating and other composite coating systems during 120 h of immersion. Polarization curve (Tafel) and electrochemical impedance spectroscopy (EIS) tests reveal that the 10%M-BNNS@EP coating not only has an excellent anticorrosion effect on the metal substrates but also has a good anticorrosion stability after being immersed in 3.5 wt % NaCl aqueous solution for 120 h.

Enhancing the Anticorrosion Performance of Graphene–Epoxy Coatings by Biomimetic Interfacial Designs

“…Despite recent progresses, many practical problems still remain unsolved. Typically, G shows corrosion-promotion activity (CPA), which will accelerate galvanic corrosion of metals at coating defects. , Polymer encapsulation is a universal approach to eliminating the CPA of G. − However, it usually involves complex reaction, and the low graft yields are impractical for scalable industrial applications. The CPA issue of G is unsolved to date.…”

“…Natural nacre is composed of 96 vol % aragonite and 5 vol % biopolymers and exhibits extraordinary toughness and antipermeation performance, which mainly benefits from its highly ordered “‘brick-and-mortar”’ lamellar structure. − The orderly layered architecture of nacre provides a design concept for constructing high-performance G-based composite coatings and is expected to eliminate the CPA through the anisotropic feature. However, this assembly structure has been ignored in descriptions of previously reported coatings. − …”

High Anticorrosion Properties due to Electron Spin Polarization of Hydroxyapatite with Point Defects

“…To quantify the Cu-HAP protection performance, after fitting the impedance data using an equivalent circuit composed of time constants as shown in Figure e, we used the R ( QR )­( QR )­( CR ) model to simulate the electrochemical test results and determine the parameters of coating capacitance, , interfacial activity, and resistance (Table ). The impedance value ( Z ) of the sample can be calculated by eqs , where Y and n represent the scale factor and dispersion index (0 < n ≤ 1), respectively.…”

Improved anticorrosive property of waterborne epoxy coating by ultrasonic blending with small amounts of polyaniline

“…Among them, epoxy resin is extensively applied as protective coating for the metallic anticorrosion, attributed to its wide range of varieties and curing, strong adhesion,low shrinkage, excellent mechanical and electric properties, superior chemical and dimensional stability and good microbial resistance [11]. The epoxy resin coating can provide an effective protective barrier for metallic substrates and thus restrict the metallic corrosion reactions by inhibiting, shielding and cathodically protecting [12]. However, in comparison with the solvent-borne epoxy, the water-borne epoxy is not very satisfactory to act as protective coatings in practical application [13].…”

“…In order to solve these problems, many strategies have been put forward to enhance the performance of epoxy resin coatings. To approach this goal, various organic/inorganic materials have been developed as nanofillers, including boron nitride nanosheets [12], silicon nitride nanoparticles [14], clay [15], modified graphene [16] and conducting polymers [17].…”