tailieunhanh - Báo cáo hóa học: " Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites | Nedim Ay et al. Nanoscale Research Letters 2011 6 116 http content 6 1 116 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks Ring Nebula-like nanocomposites Ahmet Nedim Ay Deniz Konuk Birgul Zumreoglu-Karan Abstract A new nanocomposite architecture is reported which combines prolate spheroidal hematite nanoparticles with drug-carrying layered double hydroxide LDH disks in a single structure. Spindle-shaped hematite nanoparticles with average length of 225 nm and width of 75 nm were obtained by thermal decomposition of hydrothermally synthesized hematite. The particles were first coated with Mg-Al-NO3-LDH shell and then subjected to anion exchange with salicylate ions. The resulting bio-nanohybrid displayed a close structural resemblance to that of the Ring Nebula. Scanning electron microscope and transmission electron microscopy images showed that the LDH disks are stacked around the equatorial part of the ellipsoid extending along the main axis. This geometry possesses great structural tunability as the composition of the LDH and the nature of the interlayer region can be tailored and lead to novel applications in areas ranging from functional materials to medicine by encapsulating various guest molecules. Introduction Magnetic iron oxide nanoparticles have attracted extensive attention in biomedicine and nanotechnology areas 1 2 . Among them hematite a-Fe2O3 is the oldest known most stable and cheapest iron oxide with n-type semiconducting and soft magnetic properties 3 . Since the report of Matijevic and co-workers in the early 1980s 4 much progress has been made toward the synthesis of monodisperse hematite particles with many different shapes that offer promising uses in water splitting photocatalysis photoelectrochemistry magnetic recording media and other nanodevices 5-7 . For practical applications .