Optical release layer

Fig. 11 (a) Optical microscopy images of the release from ibuprofen crystals covered with a (CHI/dextran sulfate)is shell 1 before dissolution 2 during dissolution and 3 after removal of the crystal cores. The mean size of the encapsulated ibuprofen microcrystals is 15.3 am. Reproduced from [112]. (b) Fluorescence increases with time, obtained by dissolving fluorescein crystals covered with shells of different thicknesses (9, 13, 15, and 18 polyelectrolyte-deposited PSS/PAH layers). The release from the native (uncovered) fluorescein crystals is shown as 0. Reproduced from [122]... 

S). Crystals of these compounds are Qrst cleaved between glass slides coated with a polystyrene cement and then released and washed with acetone. These sections are mounted on glass slides with aqueous polyvinylpyrolidone (PVP) adhesive. The PVP is allowed to harden and the crystals are further cleaved with Scotch tape. Successive layers are removed until an optically transparent portion of the crystal remains affixed to the slide. Such crystals, which vary in thickness from 15 to 100 nm, are good electron transmission specimens. The cleaved ciyrstals are released from the slide onto a clean water surface and picked up on a microscope grid. 

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