Fiber with Butterfly Wings: Creating Colored Carbon Fibers with Increased Strength, Adhesion, and Reversible Malleability

Abstract

Colored and color-changing materials are central to perception and interaction in nature and have been exploited in an array of modern technologies such as sensors, visual displays and smart materials. Attempts to introduce color into carbon fiber materials have been limited by deleterious impacts on fiber properties, and the extension of colored fibers towards 'smart composites' remains in its infancy. We present carbon fibers incorporating structural color, similar to that observed on the surface of soap bubbles and various insects and birds, by modifying the fiber surface through in situ polymerization grafting. When dry, the treated fibers exhibit a striking blue color, but when exposed to a volatile solvent, a cascade of colors across the visible region is observed as the film first swells and then shrinks as the solvent evaporates. The treated fibers not only possess a unique color and color-changing ability, but can also be reversibly formed into complex shapes and bear significant loads even without being encased in a supporting polymer. The tensile strength of treated fibers shows a statistically significant increase (+12%) and evaluation of the fiber-to-matrix adhesion of these polymers to an epoxy resin shows more than 300% improvement over control fibers. This approach creates a new platform for the multifaceted advance of smart composites.

Using redox active molecules to build multilayered architecture on carbon fibers and the effect on adhesion in epoxy composites

“…Finally, the determination of interfacial shear strength of the functionalized fibers was undertaken using the single filament fragmentation test (SFFT) in an epoxy resin, as per our previous publications. [32][33][34] The pristine fiber samples showed a very poor IFSS (18.1±0.7 MPa), as would be expected, as this sample had not undergone any surface treatment or sizing. 6).…”

Color adjustment potential of single-shade resin composite to various-shade human teeth: Effect of structural color phenomenon

“…The application research of structural colors in industries such as textile and automotive is ongoing 18,19) . Among the methods of manufacturing artificial structural colors, bottom-up methods based on assembling colloidal nanoparticles are considered to be the most promising in adjusting the wavelength range of the structural color 20) , because it is assumed that the size of the minute structures enhances a specific color tone [21][22][23] .…”

Using In Situ Polymerization to Increase Puncture Resistance and Induce Reversible Formability in Silk Membranes

“…A piece of 40% glycerol (Sigma-Aldrich, St Louis, MO, USA) casted silk membrane (designated untreated) (1 cm 2 ) was dipped in ascorbic acid (Sigma-Aldrich, St Louis, MO, USA) (0.02 M) and air dried for 12-24 h. A vial was then filled with sulfuric acid (Sigma-Aldrich, St Louis, MO, USA) (10 mL, 0.01 M) and diazonium salt (2 mM) prepared according to literature procedure [30]. This solution was stirred for 10 min to allow the diazonium salt to dissolve before adding acrylic acid (Sigma-Aldrich, St Louis, MO, USA) (480 µL).…”

“…This process is applicable to a wide array of conductive materials (metals, carbons, etc.) and was recently applied to carbon fibers to great effect [30]. The monomer of interest in this report is acrylic acid, which is generated as a by-product of ethylene and gasoline production.…”