Self-assemblies of amphiphiles in solutions were investigated by using freeze-fracture transmission electron microscopy(FF-TEM). Especially, vesicles were characterized by FF-TEM and the transition of self-assemblies was determined. The stacked lamellar Lα-phase was prepared without shear forces by a chemical reaction. The stacked lamellar Lα-phase can be transformed into multilamellar vesicles by the shearing forces that occur when the stacked lamellar Lα-phase sample is turned upside down a few times. The multilamellar vesicles can also be transformed into unilamellar vesicles by high shearing forces. These transitions were demonstrated by FF-TEM measurements. Zn2+-induced vesicle formation in the single-chain surfactant solutions was first achieved.
The paper describes the fabrication of polypyrrole (PPy) microstructures through pat-terned self-assembled film guided electrodeposition. Thus the patterned self-assembled monolayer is prepared by microcontact printing (mCP) and used as the template in the electro-deposition of PPy. It has been found that the self-assembled monolayer plays completely differ-ent roles on different substrates in directing the deposition of the PPy. Namely, the electrode-position mainly occurs on the exposed area of the gold substrates patterned with dodecanethiol (DDT) and octadecanelthiol (ODT) and on the indium tin oxide (ITO) substrate patterned with octadecyltrichlorosilane (OTS), while PPy nucleates on the OTS covered area and no deposition is found on the exposed area of a semiconductor substrate (silicon). This is attributed to the co-operative effect between the substrate conductivity and the compatibility of the PPy oligomer with the covered or exposed area of the substrate surface.
ZHOU Feng1, LI Bin1,2, XU Tao1, CHEN Miao1, HAO Jingcheng1 & LIU Weimin1 1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
A series of novel metal halide-stabilized linear phosphazene derivatives were synthesized. The friction-reducing and antiwear abilities of the resulting products as the lubricants for a steel-on-steel contact were comparatively investigated on an Optimol SRV oscillating friction and wear tester. The morphology of the worn steel surface was observed on a scanning electron microscope, while the chemical states of some typical elements on the worn steel surface were examined by means of X-ray photoelectron spectroscopy. It was found that both the side branch structures and central metals influenced the friction-reducing and antiwear behaviors of the synthetic derivatives as the lubricants, which was related to the different adsorption activities of the organic compounds composed of different organic ingredients and metallic ions on a nascent metal surface. All the synthetic lubricants except for the iron (III) derivative showed increased antiwear abilities with increasing metallic ionic radius. A protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic fluorine compounds, nitrogen oxide, and Fe 3 (PO 4 ) 2 plays an important role in improving the friction and wear behavior of the steel-on-steel system.
ZHU Jiamei 1,2 , LIU Weimin 2 & LIANG Yongmin 2 1. School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221008, China
