Ionothermal synthesis of layered zirconium phosphates and their tribological properties in mineral oil.
In an attempt to synthesize novel zirconium phosphate materials, a series of syntheses have been performed in a deep eutectic solvent (DES), composed of tetrapropylammonium bromide (TPABr) and oxalic acid. As a result, this DES does not act as a template provider in reaction probably owing to the steric effects of the longer chains of the TPA cation, and only the α-Zr(HPO(4))(2)·H(2)O (α-ZrP) phase has been achieved. However, after organic amine was added to the initial reaction mixture in a normal way, the additives did act as a template to induce the zirconium phosphate framework. For example, with 1,4-dimethylpiperazine as an additive, a novel layered compound, [C(6)H(16)N(2)](0.5)Zr(H(0.5)PO(4))(2)·H(2)O (denoted as ZrPO(4)-DES8) was obtained. Its structure was determined from single-crystal X-ray diffraction (XRD) data and consists of zirconium phosphate layers with the protonated 1,4-dimethylpiperazine and water molecules in between. Interestingly, the two layered materials as additives in a liquid lubricant exhibit excellent friction behavior with higher load-carrying and antiwear capacities in comparison to typical lubricant additives such as MoS(2) and graphite, increase the P(B) value of the base oil by 27.2% and 8.5%, and decrease the wear scar diameter of the base oil by 43% and 36%, respectively. Scanning electron microscopy, XRD, and energy-dispersive X-ray spectrometry are used to investigate the lubricant behavior of those materials.
Liu
Lei
L
Research Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan 030024, Shanxi, People's Republic of China.
Chen
Zhao-Feng
ZF
Wei
Hai-Bo
HB
Li
Yang
Y
Fu
Yu-Chuan
YC
Xu
Hong
H
Li
Jin-Ping
JP
Slawin
Alexandra M Z
AM
Dong
Jin-Xiang
JX