Abstract: A procedure for obtaining nanofibrillated cellulose starting from a raw material including recycled or recovered paper, or recovered paper pulp or recovered cellulose comprises the stages of: immersing the raw material in an acetic acid dilution, in a concentration of 10% to 50% by volume, during a time inverse to the concentration of acetic acid; stirring the raw material immersed in the acetic acid dilution; and subsequently subjecting the cellulosic material to a mechanical process of longitudinal separation of fibers, by shear forces applied through a mixer or similar equipment capable of creating enough shearing on cellulose pulp. Thanks to the above procedure nanofibrillated cellulose from recycled paper is obtained with similar features to the nanofibrillated cellulose obtained from virgin cellulose.

Abstract: A procedure for obtaining nanofibrillated cellulose starting from a raw material including recycled or recovered paper, or recovered paper pulp or recovered cellulose comprises the stages of: immersing the raw material in an acetic acid dilution, in a concentration of 10% to 50% by volume, during a time inverse to the concentration of acetic acid; stirring the raw material immersed in the acetic acid dilution; and subsequently subjecting the cellulosic material to a mechanical process of longitudinal separation of fibres, by shear forces applied through a mixer or similar equipment capable of creating enough shearing on cellulose pulp. Thanks to the above procedure nanofibrillated cellulose from recycled paper is obtained with similar features to the nanofibrillated cellulose obtained from virgin cellulose.

Abstract: The present invention relates to a system comprising magnetic nanoparticles of a metal oxide and a polymer, which in turn contains monomers with different functional groups. This system can be solid (nanocomposite) or liquid (ferrofluid). The present invention also relates to a process for obtaining the system, as well as its use, mainly in biotechnological, veterinary and medical applications, such as, for example, for the diagnosis and treatment of human diseases.

Abstract: Method of layer-by-layer (LbL) assembly of oppositely charged polyelectrolytes was applied to coat fluorescein particles. These particles with a size of 4-9 &mgr;m were prepared by precipitation of fluorescein at pH 2. Polysterensulfonate (PSS) and polyallylamine (PAH) were used to compose the polyelectrolyte shell on the fluorescein core. The release of fluorescein molecules through the polyelectrolyte shell core dissolution was monitored at pH 8 by increasing fluorescence intensity. The number of polyelectrolyte layers sufficient to sustain fluorescence release was found to be 8-10. Sequentially adsorbed layers prolong core dissolution time for minutes. The permeability of polyelectrolyte multilayers of the thickness of 20 nm is about 10−8 m/s. Mechanism of fluorescence diffusion and osmotically supported release is under discussion. The features of release profile and possible applications or LbL method for shell formation in order to control release properties for entrapped materials are outlined.