Abstract: The present invention provides calcium phosphate platelets with a length between 250 nm and 800 nm and methods for producing the calcium phosphate platelets. The platelets may be used to provide dispersions or colloidal dispersions obtained by suspending the platelets in the presence of a dispersing agent. The platelets may be used in reinforcing fillers, polishing agents, building materials, additives for oral formulations, in dentrifices or in encapsulating agents.

Abstract: The invention provides separated calcium phosphate platelets with a length of between 250 nm and 800 nm. The invention also provides dispersions comprising the platelets according to the invention or colloidal dispersions obtained by resuspending the said platelets in the presence of a dispersing agent. The invention also relates to a process for preparing platelets according to the invention. Finally, another subject-matter of the invention is the use of the abovementioned platelets as reinforcing filler, polishing agent, building materials, additive for oral formulations, in particular dentifrices, or encapsulating agent.

Abstract: The invention concerns a stable aqueous colloidal dispersion of colloids with apatite structure, having a pH ranging between 5 and 10.5, comprising a bifunctionalised stabilising agent having a first amine or ammonium function and a second function capable of complexing calcium, and consisting of oblong colloids with an average number length ranging between 5 and 100 nm and an equivalent aspect ratio (number average length/equivalent diameter ratio) ranging between 2 and 300, said colloids with apatite structure corresponding to the formula: Ca10-x(HPO4)x(PO4)6-x(J)2-x, wherein x and J are such as defined in claim 1.

Abstract: The invention relates to a material which can be implanted in living tissue, in particular bony tissue, and having a rate of biodegradation adapted to the rate at which the tissue is regenerated; this material may comprise an active substance in order to achieve a therapeutic effect of prolonged duration. This material comprises (a) a calcium phosphate with apatitic or triclinic structure comprising HPO.sub.4 and PO.sub.4 groups, (b) a biodegradable oside or polyoside, in particular dextran, (c) if required, an active substance comprising amine groups such as netilmicin and/or gentamicin in sulphate form. The implantable material according to the invention may be produced without heat by compacting its various constituents in the powdery state.

Abstract: A process for depositing a layer of a semiconductor composition comprising elements M(III) and M'(V) selected from group III and group V elements, respectively onto a substrate. The process comprises: contacting the substrate with a coordination compound in the gaseous phase, the compound having the formula: ##STR1## wherein M(III) and M'(V) are bonded to one another by a donor/acceptor bond and wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are chemical radicals other than hydrogen with at least one of the radicals R.sub.1, R.sub.2, and R.sub.3 being an electron donor serving to stabilize the donor/acceptor bond between elements M(III) and M'(V). The process further comprises decomposing the coordination compound so as to break the chemical bonds between the radicals and the elements M(III) and M'(V) without breaking the donor/acceptor bond, so as to cause the semi-conductor composition to deposit onto the substrate.