Dynamic Thin Films in Controlling the Fabrication of Nanocarbon and Its Composites

Abstract

journey of discovery for other carbon nano materials, which have properties beyond those of the classical allotropes of carbon. Other new forms of more recently established nanocarbon include single walled carbon nanohorns, [13,14] carbon nanoonions, [15][16][17] carbon nanorings, [18][19][20] cup-stacked carbon nanotubes [21,22] and carbon hybrid materials. [23] Methods for fabricating carbon nanomaterials have been extensively studied, in establishing robust syntheses, which is important for their use in down stream applications. Conventional methods of fabricating these materials have evolved, using both the 'top down' and 'bottom up' approaches, with some advance towards developing more benign processes and in addressing the often-vexing question of scalability of the methods, but this is often rather challenging. Centuries ago, elemental carbon was known to exist as two natural occurring allotropes, diamond and graphite, which have different structures and properties. Their physical and chemical properties depend on the arrangement of the carbon atoms. Diamond has a tetrahedral arrangement of sp 3 carbon atoms while graphite is comprised of stacked sheets of graphene held together by van der Waals interactions. Each graphene sheet consists of sp 2 carbon atoms arranged in two-dimensional hexagonal lattices. Diamond is typically used as a transparent electrical insulator while graphite is a black soft material with excellent electrical conductivity. The spark of a new era in allotropes of carbon beyond diamond and graphite began with the discovery of fullerene C 60 and other members of the fullerene family such as C 70 . [24,25] Of particular importance are the onedimensional (1D) carbon nanotubes and two dimensional (2D) graphene sheets, which have created new avenues in material science. The physical and chemical interactions of these carbon nanomaterials are determined mainly by their geometrical structure and method of synthesis. Conventional batch processing methods have dominated the field of fabricating carbon nanostructures in various morphologies and dimensions for specific applications, but they can have limitations, specifically in terms of environmental impact issues, economic sustainability, scalability and the quality of the material. The ability to precisely control the formation of a diverse range of functional materials at the nanoscale length, with scalability incorporated into the processing, is important for future uptake by industry in a myriad of applications. This review focuses on the use of continuous flow thin film microfluidic platforms for the Thin film microfluidics are developed for a wide range of applications, including the synthesis of various types of nanocarbon material, involving both 'top down' and 'bottom up' continuous flow processing. This type of processing addresses scalability at the inception of the science, and is applicable not just to the synthesis of nanocarbon, but also composites or hybrid material where one or more components is nanocarbon. This review introd...

Inverted vortex fluidic exfoliation and scrolling of hexagonal-boron nitride

“…The SDP was the forerunner to the development of the vortex uidic device (VFD), which is more practical for research purposes, while also addressing scalability of the processing, and is signicantly cheaper. 26 We have explored using the VFD to form h-BN scrolls from h-BN in water under continuous ow mode of operation in the device, establishing ca. 10% yield conversion for a single pass through the microuidic platform.…”

“…The VFD is a more versatile platform and can be operated at different tilt angles, which is usually not the case for the SDP. 26 In addition, the VFD can operate under continuous ow as well as under the conned mode, where a nite volume of liquid is placed in the rapidly rotating tube. The shear stress here is sufficient to exfoliate graphene from graphite, and also single h-BN sheets from h-BN akes, albeit in low yield, and without forming scrolls.…”

A Survey of Tactile‐Sensing Systems and Their Applications in Biomedical Engineering

“…ere are two main pathways to transmit tactile information to the CNS, namely, the dorsal-medial lemniscal pathway and the spinothalamic pathway [39]. e spinothalamic pathway is part of the anterolateral system, and it transmits information to the thalamus about temperature and pain, while the dorsal column-medial lemniscus pathway transmits vibration, pressure, and shared position information from mechanoreceptors to the CNS [40,41].…”

Microfluidic Devices in Fabricating Nano or Micromaterials for Biomedical Applications

“…This technology achieves large‐scale automated production, with intimate mixing, high mass and heat transfer rate, and enhanced surface interactions . This processing platform has gradually attract lots of interests as viable alternatives to conventional batch processing with two recent reviews on SDP in general and its application on nanocarbon processing . SDP fulfils the need of mass production at reasonable market cost and has been applied to synthesize polymer nanoparticles mostly for drug delivery purpose .…”

“…However, MDs are not limited toward chip or channel‐based systems which are dominated by laminar flow. Significant advances have been made in the field in the last decade toward developing MDs and micromixers for intensified micromixing which are dominated by turbulent flow, with exquisite control of material properties and functions . Additionally, it is believed that the biomedical related application of MD‐generated particles are more than the areas being covered thus far.…”