Film/coating formation stages

The paper is coated 1 on 1 side with this compn. in an amt. sufficient to provide a dry film coating of 6-15 lb/3000 ft. Of paper, dried by evapg. the solvent at a rate to prevent blister formation, and coated on the other side with the same amt. of photosensitive compn. but in multiple stages of coating and drying such that in each stage 10-60% of the total wt. is applied. 

By carrying out the last stages in the abrading procedures under purified kerosene, we tended to minimize the formation of films. These specimens were coated with the oxide films normally formed at room temperature. They were heated to the reaction temperature as quickly as possible in the highest obtainable vacuum. 

Fig. 2 A schematic for spin coating thin films. The coating solution is either (A) dripped on the substrate while it is at rest or (B) dripped on while the substrate is spinning (C) spin-off stage, forming a thin liquid coating on the substrate (D) solvent evaporation results in self-assembly and thin film formation.

Chambers for oxygen consumption measurements are prepared from microscopic slides coated with a thin paraffin film. With a tip of a hypodermic needle held in a micromanipulator, a small round dent of 10—15 pm is made in the paraffin film, and a drop of 40% HF applied to the dent enables the formation of small circular cavities visible after the removal of paraffin. To increase the measuring capacity, an automatic cuvettechanging device has been developed. The object stage maintained at constant temperature by water circulation from a temperature controlled bath, is moved in six discrete steps by a synchronous motor. Thus, oxygen consumption in six different chambers can be assayed simultaneously. The basic equipment used for microspectrophotometric determinations of oxygen consumption does not differ essentially from the equipment used for other purposes, such as cytophotometry (Hamberger et al., 1975). 

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