Thinner libers

Structure of parallel stripes with respect to the long liber axis with a spacing 3 nm (comparable to the diameter of the thinner fibrils observed in samples with a concentration below 0.25 mM). The 3 nm fibrils correspond quite well to the diameter of a discotic molecule of the gelator and most likely result from the single stacks of the molecules of 9c hydrogen bonded in the z-direction. These thinner fibrils subsequently associate into parallel bundles resulting in 9 nm fibers stabilized by hydrophobic interaction between the aliphatic chains (a schematic representation of the self-assembly is shown in Fig. 6.11). 

The reason why needle-shaped amphibole asbestos fibers typically penetrate into the pleural cavity, whereas chrysotile fibers do not, lies in their different morphology and pliability. Microscopic examination reveals that amphibole asbestos fibers are indeed needle-like, rigid for their small diameter (typically only a few pm), and straight. Chrysotile libers on the other hand are somewhat thinner, often longer, frequently curved, and even somewhat curly, which makes then less capable of piercing living tissue, so that they are more prone to remain in situ, until digested. 

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