In order to increase the usability of PLA in tissue engineering, we tried to improve the hydrophobicity and low mechanical properties of PLA. The basic solutions were prepared by mixing 3, 5, and 7wt.% of PLA in a solution of chloroform and acetone in a volume ratio of 3:1. Several types of nanofiber mats were fabricated using a mixed solution in which 0.5, 1, and 3wt.% of PEO and PVAc, which are biodegradable polymers, were added to these solutions, respectively, through the SBS method. As a result, it was found that when the content of PEO increased, the diameter and surface state of nano fibers became uniform and the water contact angle significantly decreased, but it did not affect the tensile strength. In addition, the hydrophobicity of PLA was improved to hydrophilicity by mixing with PVAc, but the strain was greatly reduced.

Silicon alloys are considered promising anode active materials to replace Li-ion batteries by graphite powder, because they have a relatively high capacity of up to 4200 mAh/g, and are environmentally friendly and inexpensive ECO-materials. However, its poor charge/discharge properties, induced by cracking during cycles, constitute their most serious problem as anode electrode. In order to solve these problems, Si-Ge-Al alloys with porous structure are designed as anode alloy powders, to improve cycling stability. The alloys are melt-spun to obtain the rapidly solidified ribbons, and then ball-milled to make fine powders. The powders are etched using 1 M HCl solution, which gives the powders a porous structure by removing the element Al. Subsequently, in this study, the microstructures and the characteristics of the etched powders are evaluated for application as anode materials. As a result, the etched porous powder shows better electrochemical properties than as-milled Si-Ge-Al powder.

Mechanical alloying technique was applied to prepare hard magnetic compound powders. Staring from pure Fe and Sm powders, the formation process of hard magnetic phase by mechanical alloying and subsequent solid state reaction was studied. As milled powders were found to consist of Sm-Fe amorphous and -Fe phases in all compositions of (x = 11, 13, 15, 17). The effects of starting composition on the formation of intermetallic compound was investigated by heat treatment of mechanically-alloyed powders. When Sm content was 15 at.％, heat-treated powders consisted of nearly single phase. For preparation of hard magnetic powders, additional nitriding treatment was performed under gas flow at 45. The increase in the coercivity and remanence was proportional to the nitrogen content which increased drastically at first and then increased gradually as the nitriding time was extended to 3 hours.