LiAlH4 and AlCl3 reacted in a ratio 1:3 to obtain Cl2AlH, which is stabilised by the addition of two equivalents of N‐methylpiperidine (nmp) to form dichloroalane (1) as bis adduct of nmp. Compound 1 was allowed to react with 2,6‐tBu‐4‐MeC6H2OH and HOcHex in a 1:1 ratio to get compounds 2 and 3, respectively. Cl2Al(2,6‐tBu‐4‐MeC6H2O)(nmp) (2) is a monomer in which the central aluminium atom is tetracoordinate. Contrary to the parent compound 1, compound 2 is stabilised by only one nmp molecule. The larger bulk of the alkoxide in 2 prevents the second nmp molecule to reach the aluminium atom. Compound 3 crystallises as unique anionic tri‐nuclear aluminium entity [Al3Cl6(OR)4]– [nmp2H]+ with a protonated nmp as countercation. The lesser bulk of the cyclohexanolate leads to a higher oligomerisation of ROAlCl2 (R = cyclohexyl). When a relatively bulkier alcohol, 1‐methylcyclohexanol, was allowed to react with mixtures of LiAlH4 and AlCl3 prepared in 1:1 and 1:3 ratios in solution, compounds 4 and 5, respectively, were obtained. Both compounds ((HClAlOR)2 (4) and (Cl2AlOR)2 (5), R = cHexMe‐1)) are dimers with oxygen as bridging atom in the Al2O2 rings. All compounds 2, 3, 4, and 5 were structurally characterised by X‐ray diffraction on single crystals.
The development of micro- and nanostructured surfaces which improve the cell-substrate interaction is of great interest in today's implant applications. In this regard, Al/Al2O3 bi-phasic nanowires were synthesized by chemical vapor deposition of the molecular precursor (tBuOAlH2)2. Heat treatment of such bi-phasic nanowires with short laser pulses leads to micro- and nanostructured Al2O3 surfaces. Such surfaces were characterized by scanning electron microscopy (SEM), electron dispersive spectroscopy and x-ray photoelectron spectroscopy. Following the detailed material characterization, the prepared surfaces were tested for their cell compatibility using normal human dermal fibroblasts. While the cells cultivated on Al/Al2O3 bi-phasic nanowires showed an unusual morphology, cells cultivated on nanowires treated with one and two laser pulses exhibited morphologies similar to those observed on the control substrate. The highest cell density was observed on surfaces treated with one laser pulse. The interaction of the cells with the nano- and microstructures was investigated by SEM analysis in detail. Laser treatment of Al/Al2O3 bi-phasic nanowires is a fast and easy method to fabricate nano- and microstructured Al2O3-surfaces for studying cell-surface interactions. It is our goal to develop a biocompatible Al2O3-surface which could be used as a coating material for medical implants exhibiting a cell selective response because of its specific physical landscape and especially because it promotes the adhesion of osteoblasts while minimizing the adhesion of fibroblasts.
A comprehensive study of synthesizing zeolite nanoparticles, with the addition of organic template, by reflux method has been chalked out to form crystals. The method is effectivly for the synthesis of zeolite nanocrystals, incorporating alkali metals, silica and organic template. The organic templates tetra-propyl ammonium hydroxide (TPAOH), tetra-propyl ammonium bromide (TPABr) or (TPABr, N,N,N-tripropyl-1-propanaminiumbromide), tetraethyl orthosilicate (TEOS) were added to assist the formation of zeolite (Albite) crystals. A cross linker tetraethyl orthosilicate (TEOS) was also mixed. Addition of carbon nanotubes (CNTs) and graphene oxide (GO) resulted into a unique nano morphology of Albite (when the time of reaction was less than 240 h). Effect of additives on morphology, particle size, crystal geometry, surface area, and particle shapes was characterized with FT-IR, X-ray diffraction, BET, EDX and SEM. For the practical point of view, Kevlar supported polymer membrane with the Zeolite as catalyst is used. Results show that polymeric supported fabric and catalyst supported fabric have same result with response to mechanical testing. This suggest that the Kevlar supported polymer membrane has potential application in industrial cables, asbestos replacement brake lining, under water applications, tyres, and body armors.
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