No abstract

A novel polyvinylidene fluoride (PVDF) nanocomposite membrane containing graphene oxide nanoribbones (GONRs) as a new nanofiller and polyvinylpyrrolidone (PVP) as pore former agent was prepared via phase inversion method. GONRs were prepared by oxidative unzipping of multi-walled carbon nanotubes (MWCNTs) via chemical approach. Chemical vapor deposition method was used to synthesis MWCNTs. The effects of adding GONRs and PVP into the casting solution on morphology, hydrophilicity and pure water flux (PWF) of the prepared nanocomposite membranes were explored. Antifouling experiments were also performed. It was found that compared to the neat PVDF membrane, PWF of the PVDF/PVP, PVDF/(0.5GONRs) and PVDF/(0.5GONRs)/PVP membranes were improved 80%, 44.9%, and 241.6%, respectively. The obtained results showed that GONRs and PVP exhibit synergistic effects in controlling the membrane properties. This work shows that GONRs can be suitable as nanofiller for preparation of high performance PVDF ultrafiltration membranes with improved antifouling properties.

The goal of research was the comparison of legal literacy level of elementary and secondary school teachers. The research design was a descriptive-correlational method. By using stratified sampling method 158 teachers were selected and pariticipated in the study. Research tool was a researcher made questionnaire beasd on the dimentions of legal literacy. The results showed that the teachers of elementary and secondary schools have not appropriate legal literacy. The findings also indicate that there is a significant difference in legal literacy between male and female teachers, and there is no significant difference between the legal literacy of elementary and secondary school teachers.