ABSTRACT
This article reports a study of the effects of synthesis parameters on the preparation and formation of mesoporous titania nanopowders by employing a two-step sol-gel method. These materials displayed crystalline domains characteristic of anatase. The first step of the process involved the hydrolysis of titanium isopropoxide in a basic aqueous solution mediated by neutral surfactant. The solid product obtained from step 1 was then treated in an acidified ethanol solution containing the same titanium precursor to thicken the pore walls. Low pH and higher loading of the Ti precursor in step 2 produced better mesoporosity and crystallinity of titanium dioxide polymorphs. The resultant powder exhibited a high surface area (73.8 m2/g) and large pore volume (0.17 cm3/g) with uniform mesopores. These materials are envisaged to be used as precursors for mesoporous titania films as a wide band gap semiconductor in dye-sensitized nanocrystalline TiO2 solar cells.
Subject(s)
Crystallization/methods , Materials Testing , Nanotechnology/methods , Titanium/chemistry , Manufactured Materials/analysis , Molecular Conformation , Phase Transition , Porosity , Surface Properties , Titanium/analysisABSTRACT
PIP: The reproductive health needs of rural women in Bali, Indonesia, were investigated through a survey conducted in 1995 in three of Bali's eight districts and focus group discussions with 23 nurse-midwives who serve the target population. Mean age at marriage was 21.0 years and mean age at first intercourse was 20.9 years. 85.1% of the 295 survey respondents were using a modern contraceptive method, primarily the IUD and Depo-Provera. Only 10.6% of respondents had ever used a condom. Of the 163 women who had ever experienced an adverse reproductive health symptom (e.g., vaginal discharge), 69 (42.3%) did not seek help from a medical provider. Among those who sought medical attention, 55 (58.5%) went to the community health center, 47 (50%) saw a private practice nurse, and 25 (26.6%) consulted a private practice doctor. 73.1% of respondents were satisfied with women's health services available in their area and 94.5% of ever-users of contraception were satisfied with family planning services. However, women indicated a need for more information on AIDS and other sexually transmitted diseases (STDs). 52.2% of women had never received any information about AIDS and 69% had not been counseled about STDs. The nurse-midwives reported they had never received special training in STDs and HIV/AIDS and did not feel equipped to respond to patients presenting with symptoms or questions. The strong health-seeking behavior and basic satisfaction with health care services documented in this study provide a good basis for strengthening reproductive health care programs in Bali.^ieng
