Preparation and utility of a self-lubricating & anti-wear graphene oxide/nano-polytetrafluoroethylene hybrid

Abstract

Graphene oxide/nano-PTFE (GNF), combining intrinsic functions from graphene oxide and nano-PTFE, as a self-lubricating and anti-wear additive, reduces friction coefficient and further increases wear resistance.

Study on Preparation of BaSO4‐Containing Polytetrafluoroethylene Granular Powder

“…BaSO 4 -containing PTFE granular powder was prepared by granulation of the mixture of PTFE powder and BaSO 4 with stirring in an aqueous medium, which consists of ion-exchanged water, methylene chloride, and a specific surfactant. And the granulating process could be performed without a uniform granulator or apparatus.…”

“…PTFE powder and BaSO 4 were dried in an oven at 130ºC for 3 h. Then they were cooled and put aside in a dry place below 19ºC for 24 h. The mixture of PTFE powder and BaSO 4 was obtained by premixing them with a high-speed mixer (self-made). The BaSO 4 content is 30% by weight with respect to the total weight of PTFE powder and BaSO 4 .…”

“…The white opaque appearance and its high density are exploited in many applications. After filled PTFE with BaSO 4 , it has an effect of increasing acid and alkali resistance and opacity and also has a long operating life, 1,4,9,17 To address the above-mentioned problems, we have conducted research on the preparation of the BaSO 4 -containing PTFE granular powder by granulating of the mixture of PTFE powder and BaSO 4 with stirring in an aqueous medium, which consisting of ion-exchanged water, methylene chloride ,and an anionic surfactant or a nonionic surfactant. The granulating process different from the reported literatures was performed without a uniform granulator or apparatus.…”

“…[1][2][3][4] However, finely powdered PTFE shows very poor powder flow properties and also low bulk density. These two major disadvantages lead to PTFE is unsuitable for use in automatic molding machines and also adversely affect its ability to completely fill small or intricate molds to afford suitable molded articles.…”

“…In response to the above-mentioned problems, PTFE granular powder (also referred to as pelletized or agglomerated PTFE) has been developed; it exhibits much better powder flow properties and higher bulk density, as compared to finely powdered PTFE. [3][4][5][6][7][8] To prepare a PTFE granular powder, various processes have been proposed through agglomerating PTFE primary particles, which were obtained by pulverizing the raw PTFE suspension powder. 6,[9][10][11] As an approach for granulating PTFE, there is a method wherein only a water-insoluble organic liquid is used as a solvent or a method wherein granulation is carried out in a two-phase liquid medium comprising water and an organic liquid.…”