Morphology tubule with helical-ribbon

The experiments discussed in this chapter have shown that a variety of chiral molecules self-assemble into cylindrical tubules and helical ribbons. These are indeed surprising structures because of their high curvature. One would normally expect the lowest energy state of a bilayer membrane to be flat or to have the minimum curvature needed to close off the edges of the membrane. By contrast, these structures have a high curvature, with a characteristic radius that depends on the material but is always fairly small compared with vesicles or other membrane structures. Thus, the key issue in understanding the formation of tubules and helical ribbons is how to explain the morphology with a characteristic radius. 

Morphology evolution with time has been reported. As explained in Fig. 5, tubular morphology may be derived from the growth of a helical ribbon, and such transitions have often been observed experimentally [65,88]. Going from tubules to ribbons is also possible. In a mixture of diacetylenic... 

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