Day: March 20, 2012

Tuesday, 20 March 2012

08:10 – The methyl cellulose arrived yesterday, along with a bunch of other chemicals. I’ll make up the solution later this week.

Methyl cellulose is interesting stuff. It’s freely soluble in cold water, but insoluble in hot water. One might therefore reasonably assume that the way to make up a solution of it is to dissolve it in cold water, but that doesn’t work very well. No matter how careful you are, if you mix methyl cellulose powder with cold water, it forms clumps that are almost impossible to get into solution. The trick is to make a suspension of the stuff in water at about 85 C to prevent clumping, and then pour that suspension slowly and with constant stirring into ice cold water. The tiny particles in suspension immediately dissolve in the cold water, forming a homogeneous solution. Alternatively, one can simply make a suspension of the full amount of methyl cellulose powder in hot water and then stick the beaker in the freezer to cool it down rapidly, before the suspension has time to settle out.

The biology book is proceeding on schedule. We’re supposed to receive the QC2 PDF Thursday. We then have Thursday and Friday to review it and make any final minor changes. Once that’s complete there’ll be an index review, followed by the book going to the printer on 6 April.

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