Single cell physical properties

Physical Properties. According to Lagowski (Ref 32), X-ray analysis of a single crystal of nitric acid shows a monoclinic unit cell (symmetry P21/a-Cfh) the following dimensions a=16.23, b=8.57, and c=6.3lA, and 0=90°. The unit cell contains 16 molecules, and the calc d is 1.895g/cc at —41.6°... 

The materials used in nonwoven fabrics include a single polyolefin, or a combination of polyolefins, such as polyethylene (PE), polypropylene (PP), polyamide (PA), poly(tetrafluoroethylene) (PTFE), polyvinylidine fluoride (PVdF), and poly(vinyl chloride) (PVC). Nonwoven fabrics have not, however, been able to compete with microporous films in lithium-ion cells. This is most probably because of the inadequate pore structure and difficulty in making thin (<25 /rm) nonwoven fabrics with acceptable physical properties. 

The short answer is no. Take (S)-alanine (in other words, alanine extracted from plants) and (R)-ala-n ine (the enantiomer found in bacterial cell walls) as examples. They both have identical NMR spectra, identical IR spectra, and identical physical properties, with a single important exception. If you shine plane-polarized light through a solution of (5)-alanine, you will find that the light is rotated to the right. A solution of (R)- alanine rotates plane-polarized light to the left. Racemic alanine, on the other hand, lets the light pass unrotated. 

Some solids with interesting physical properties possess large and complex unit cells. In understanding the physical properties of such systems, it is important to have some guidelines by which to single out the parts of their crystal... 

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