수열법을 이용한 Silica 나노복합입자의 합성과 PET/Silica Nanocomposites의 제조 및 특성

Abstract

(-) 전하를 가진 Silica에 (+) 전하를 가진 Ceria, Al로 치환된 SiO₂, TiO₂를 Silica 고형분 무게에 대해 5:1의 비율로 pH 별로 96℃로 Aging 처리하고 150℃~180℃에서 수열 처리하여 CeO₂/SiO₂ (SiCe), SiO₂/SiO₂ (SiSi), and TiO₂/SiO₂ (SiTi) 복합입자를 제조하였다. 코팅한 SiCe, SiSi, SiTi 복합입자는 TEM으로 코팅 형태를 관찰하였다. Silica와 복합입자를 PET와 용액 혼합 혹은 용융 혼합하여 복합체 제조하였고, 섬유는 용융 방사하여 제조하였다. PET 복합체는 Sheet로 제조하였고, PET 복합체 sheet와 섬유는 알카리 감량처리 후 감량률과 SEM으로 표면 형태를 관찰하고, L*을 측정하였다. PET/SiCe 복합체 및 섬유가 PET/SiO₂ 복합체 및 섬유보다 표면에 작고 균일한 미세요철을 가지고 있었고, L* 값이 작았다. PET와 입자를 함유하는 복합체 혹은 섬유의 내열성은 DSC?TG를 측정하여 관찰하였고, PET와 큰 차이가 없었다.; Silica was used as a core material and Ceria, Silica substituted for aluminum (Al-Silica), and titanium dioxide were used as shell materials. Ceria or Al-Silica or titanium dioxide having positive charge was mixed with Silica having negative charge in the particle weight ratio of 1:5 according to pH. The mixture slurry was treated aging at 96℃ and followed by hydrothermal method at 150~180℃. Morphology of CeO₂/SiO₂ (SiCe), SiO₂/SiO₂ (SiSi), and TiO₂/SiO₂ (SiTi) were observed by TEM. PET composite were prepared by solution or melt blending, PET fiber were prepared by melt spinning. Then PET composite sheets were prepared by hot presser. PET composite sheet and fiber were treated alkaline and maintained for 1h in 1M sodium hydroxide an aqueous solution. After alkaline treatment, PET composite and fiber were calculated weight loss ratio and observed morphology by SEM. The microcrater sizes and the traces of Silica removed from the surface of the alkaline etched PET/SiCe composite fiber were smaller and more uniform than those of PET/SiO₂ composite fiber. The composite materials containing ceria coated silica particles had a low value of L* compared to that of silica alone. Thermal properties were measured by DSC·TG and thermal properties of PET composite fiber were similar pure PET.