Three-dimensional patterning of solid microstructures through laser reduction of colloidal graphene oxide in liquid-crystalline dispersions

Abstract

Graphene materials and structures have become an essential part of modern electronics and photovoltaics. However, despite many production methods, applications of graphene-based structures are hindered by high costs, lack of scalability and limitations in spatial patterning. Here we fabricate three-dimensional functional solid microstructures of reduced graphene oxide in a lyotropic nematic liquid crystal of graphene oxide flakes using a pulsed nearinfrared laser. This reliable, scalable approach is mask-free, does not require special chemical reduction agents, and can be implemented at ambient conditions starting from aqueous graphene oxide flakes. Orientational ordering of graphene oxide flakes in self-assembled liquid-crystalline phases enables laser patterning of complex, three-dimensional reduced graphene oxide structures and colloidal particles, such as trefoil knots, with 'frozen' orientational order of flakes. These structures and particles are mechanically rigid and range from hundreds of nanometres to millimetres in size, as needed for applications in colloids, electronics, photonics and display technology.

Large-area graphene-based nanofiltration membranes by shear alignment of discotic nematic liquid crystals of graphene oxide

“…However, producing a membrane by this approach requires large volumes of liquid, significant time and arguably has both alignment (of the GO sheets) and scalability issues. Other liquid phase processes such as dip-coating or layer-by-layer assembly similarly have potential issues with rapid productivity 15 . Therefore, a major challenge in this field is to define robust, scalable, liquid film processing approaches to produce large-area graphene-based membranes that will bridge laboratory curiosity to industrial productivity.…”

Enhanced mechanical properties of hBN–ZrO2 composites and their biological activities on Drosophila melanogaster: synthesis and characterization

“…However, some peaks appeared in the wavenumber range from 586-590 cm À1 , 767-814 cm À1 , 1338-1383 cm À1 , and 2358 cm À1 , and conrmed the presence of ZrO 2 . 65 Eventually, an absorption band (15) was observed in the wavenumber range from 3199-3451 cm À1 in all the IR spectra of the nanocomposite samples, which was accredited to O-H stretching. (1), (2), (3), (4), .…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Recently, three dimensional (3-D) interrelated nanostructures of h-BN and graphene architectures were synthesized using numerous novel methods. [13][14][15][16][17][18] Hence, it is predictable that the growing 3-D h-BN architectures will enhance their signicance in a wide range of applications. 19,20 Owing to the heterostructures and similarity with carbon, h-BN represents elevated thermal resistance and high mechanical strength.…”

Beyond graphene oxide: laser engineering functionalized graphene for flexible electronics

“…This versatility and compatibility make the laserirradiation and graphene oxide an excellent combination for developing novel electronics attracting significant attention from researchers around the world in recent years. [18][19][20][21] Laser processing can also be adapted easily to lithography. This versatility is essential considering that UV photolithography is still the goldstandard for wafer-scale patterning in microelectronics.…”