To study the influence of solution concentration on forming precursor in synthesis large quantities of imogolite, the products were synthesized from the precursor formed from the solution of several concentrations. Imogolite were synthesized from the precursor formed from any concentration of solution, the concentration of solution on forming precursor did not influence the formation on imogolite in synthesis large quantities of imogolite. The precursor of imogolite was amorphous from the data of X-ray diffraction pattern, and the infrared spectrum of precursor was almost same as that of allophane. On the other hand, water vapor adsorption isotherms of precursor possess a sharp increase in adsorption when the relative humidity is at 0-10%. The differential thermal analysis curve of the precursor possess a endothermic peak at 360-400°C. So the precursor had a part of imogolite structure or imogolite-like structure.

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  Poly (tetrafluoroethylene) (PTFE), ethylene vinyl alcohol (EVOH) and these composite thin films were deposited by a conventional vacuum evaporation apparatus and characterized by a scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The deposition rates of these thin films increased dramatically with increase of the evaporation temperature. They decreased slightly with increase of pressures during the evaporation. Stripped patterns and micrometer size particles could be seen on the surfaces of these thin films deposited at room temperature. In stead, fibril structures could be seen on the surfaces of those thin films deposited at 250°C. Although elemental compositions of these thin films deposited at 250°C were almost the same as those deposited at room temperature, the amount of -CF₃ moiety in the PTFE thin film deposited at 250°C decreased compared to that deposited at room temperature. Pull strength between these thin films and stainless steel (SUS) substrate was evaluated. The pull strength of EVOH thin film was highest and that of PTFE thin film was lowest of the three. The pull strength decreased with decrease of the surface free energies of these thin films and it was in proportion to the PTFE and EVOH mixing ratio.

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