Gelators, dendritic

Hirao T (2007) Catalytic Reductive Coupling of Carbonyl Compounds - The Pinacol Coupling Reaction and Beyond. 279 53-75 Hirayama N, see Sakai K (2007) 269 233-271 Hirst AR, Smith DK (2005) Dendritic Gelators. 256 237-273 Holzwarth AR, see Balaban TS (2005) 258 1-38... 

As early as 1986, Newkome and co-workers initiated the field of dendritic gelators by reporting dendritic bola-amphiphiles or arborols with hydrophilic surface head groups connected by a flexible lipophilic hydrophobic spacer (Fig. 3) [37]. Unlike an amphiphile, which has an apolar chain fimc-tionalised on one end with a polar head group, bola-amphiphiles have an apolar chain which is functionalised on both ends with polar head groups. 

Furthermore, the xerogels were investigated using SEM. In certain cases, the self-assembled state exhibited a fibrous nanostructure, whilst others showed relatively wide (30-60 nm) self-assembled nanoribbons. X-ray diffraction (XRD) measurements on the dried xerogels combined with other results helped the authors to propose different modes of self-assembly for the different categories of dendritic gelators. These are illustrated in Fig. 13. 

Perhaps some of the most exciting work using one-component dendritic gelators has been performed by Stupp and co-workers. They have investigated the assembly properties of so-called dendron rod-coil molecules (Fig. 18) [59]. These dendron rod-coils are effectively tri-block copolymers, which have a flexible (coil) polymer unit attached to a well-defined linear rigid rod unit, which is, in turn, grafted to a dendritic head unit. The synthesis of... 

It is also worth noting that very few dendritic gelators are the fully spherical systems traditionally associated with dendrimer chemistry. It is intuitively clear that spherical systems will have difficulty assembling into one-dimensional fibres, and consequently it is likely that the use of non-... 

In terms of applications, it is expected that dendritic gels will have similar applications to other low molecular weight gelators. However, the branched framework of dendritic building blocks also offers a number of inherent advantages which may be of special interest. The following points offer some speculation about directions in which applications of dendritic gelators may develop in the future ... 

---