Figure

2 Photographs of CH- C1 organogels in different solvents: selleck inhibitor isooctanol, n- hexane, 1, 4- dioxane, nitrobenzene, and aniline (from left to right). Many researchers have reported that a gelator molecule constructs nanoscale superstructures such as nanofibers, nanoribbons, and nanosheets in a supramolecular gel [37–39]. To obtain a visual insight into the present gel microstructures, the typical nanostructures of these gels were studied by SEM and AFM techniques, as shown in Figures  3 and 4. From the present diverse images, it can be easily investigated that the microstructures of the xerogels of all mixtures in different solvents are significantly different click here from each other, and

the morphologies of the aggregates change from wrinkle and belt to fiber with change of solvents and gelators. Besides, more wrinkle-like aggregates with different sizes were prepared in gels of CH-C3 with an additional diphenyl group linked by ether band in the spacer part. Furthermore, the xerogels of CH-C1, CH-C3, and CH-C4 in nitrobenzene were characterized by AFM, as shown in Figure  4. From the images, it is interesting to note that morphologies of fiber, rod, and belt with different sizes were observed for the three xerogels, respectively. The morphologies of the aggregates shown in the SEM and AFM images may be rationalized by considering a commonly accepted idea that highly directional intermolecular interactions, such as hydrogen bonding or π-π interactions, favor formation of organized belt or fiber micro/nanostructures [40–42]. The differences of morphologies between different gelators can be mainly due to the different strengths of the hydrophobic force between cholesteryl segments, π-π stacking, and stereo hindrance between flexible/rigid segments in molecular spacers, which have played an important role in regulating the intermolecular

orderly stacking and formation of special aggregates. Figure 3 SEM images of xerogels. CH-C1 gels ((a) isooctanol, (b) n-hexane, (c) 1,4-dioxane, (d) nitrobenzene, (e) aniline), CH-C3 gels ((f) cyclohexanone, (g) 1,4-dioxane, (h) nitrobenzene, (i) ethyl acetate, (j) petroleum Thiamine-diphosphate kinase ether, (k) DMF), CH-C4 gels ((l) nitrobenzene, (m) aniline, (n) n-butyl acrylate, (o) DMF), and CH-N1 gels ((p) pyridine). Figure 4 AFM images of xerogels. (a) CH-C1, (b) CH-C3, and (c) CH-C4 gels in nitrobenzene. In addition, with the purpose of investigating the orderly stacking of xerogel nanostructures, XRD patterns of all xerogels from gels were measured. Firstly, the data of CH-C1 were taken as an example, as shown in Figure  5a. The curve of CH-C1 xerogel from 1,4-dioxane shows main peaks in the angle region (2θ values, 2.