Researches on the Frictional Properties of Four Different Particles

To lessen the dependence of lubricating liquid on petroleum and develop environment-friendly water-based lubricants,four water-soluble particles of spirulina,staphylococcus albus,oligonucleotides and fibroin are added in the distilled water to improve the frictional properties of water. The structures of spirulina,staphylococcus albus,oligonucleotides and fibroin are subsequently analyzed and characterized by AFM and SEM,the frictional properties of distilled water and four water-soluble lubricants evaluated by micro-friction machine and related rheological properties of lubricants assessed by rheometer. Experimental results show that (1) the structure of spirulina is spiral,that of staphylococcus albus globular,that of oligonucleotides and fibroin linear, (2) as to the frictional reduction effects,spirulina ranks No.1,followed by staphylococcus albus,and then oligonucleotides and fibroin, with the load increase,the frictional coefficient of distilled water declines,while all the frictional coefficients of the four water-soluble lubricants grow, when the sliding speed is up,all the frictional coefficients of lubricants are down, (3) the distilled water with particles added is still newtonian fluid,with growth in viscosity. It is thus analyzed that the best friction-reducing effect of spirulina lies in that the surface spiral structure is sufficient to produce adequate sliding frictional force,which is easy to overcome rolling frictional couple and make particles rolling. The increase of frictional coefficients of four water-based lubricants with the growth of load is attributable to the enlargement of rolling frictional couple of particles. While the decrease of the frictional coefficients of four water-based lubricants with the increase of sliding speed results from the gradual decomposition of particle aggregations.