http://www.digitaljournal.com/tech-and-science/science/recycle-old-newspapers-used-to-grow-carbon-nanotubes/article/562452

Recycle: Old newspapers used to grow carbon nanotubes

Posted Nov 27, 2019 by Tim Sandle
A study shows how old newspaper can be used as a low-cost and green solution for the large-scale production of single walled carbon nanotubes. The nanotubes can be used in electronics and optics technology.
Stanford engineers have created a four-layer prototype high-rise chip. In this representation  the b...
Stanford engineers have created a four-layer prototype high-rise chip. In this representation, the bottom and top layers are logic transistors. Sandwiched between them are two layers of memory. The vertical tubes are nanoscale electronic "elevators" that connect logic and memory, allowing them to work together to solve problems.
Max Shulaker
Carbon nanotubes are tiny molecules with useful physical properties, with diameters in the range of a nanometer, making them ideal for microelectronics. Single-walled versions are one dimensional, cylindrically shaped allotropes of carbon.
Complexities with the mass production of carbon nanotubes include the considerable expense involved in building suitable surfaces for chemical growth, plus methods used to scale-up processes, which are limited because only single surface growth processes are generally available.
These issues can be overcome using an unlikely source - old newspapers. Scientists from Swansea University have discovered that the considerable surface area of newspapers offers and ideal space to chemically grow carbon nanotubes. This is provided that the newspaper has been made from kaolin, which is china clay (used as sizing in newspaper production). Kaolin avoids a reaction with the growth catalyst used to trigger nanotube formation, whereas other newspaper sizing materials, like calcium carbonate cause interference.
According to principal scientist Professor Bruce Brinson: "Newspapers have the benefit of being used in a roll-to-roll process in a stacked form making it an ideal candidate as a low-cost stackable two-dimensional surface to grow carbon nanotubes."
Carbon nanotubes can be used for many applications, such as conductive films to be used with touchscreen displays for electronic devices, flexible electronics, electricity-generating fabricss, plus and antennas for 5G networks.
The development has been published in the journal C — Journal of Carbon Research. The paper is called "From Newspaper Substrate to Nanotubes—Analysis of Carbonized Soot Grown on Kaolin Sized Newsprint."