Magnetic Control over the Fractal Dimension of Supramolecular Rod Networks.

Controlling supramolecular polymerization is of fundamental importance to create advanced materials and devices. Here we show that the thermodynamic equilibrium of Gd-bearing supramolecular rod networks is shifted reversibly at room temperature in a static magnetic field of up to 2 T. Our approach opens opportunities to control the structure formation of other supramolecular or coordination polymers that contain paramagnetic ions.

Multivalent Patchy Colloids for Quantitative 3D Self-Assembly Studies.

We report methods to synthesize sub-micron- and micron-sized patchy silica particles with fluorescently labeled hemispherical titania protrusions, as well as routes to efficiently characterize these particles and self-assemble these particles into non-close-packed structures. The synthesis methods expand upon earlier work in the literature, in which silica particles packed in a colloidal crystal were surface-patterned with a silane coupling agent. Here, hemispherical amorphous titania protrusions were successfully labeled with fluorescent dyes, allowing for imaging by confocal microscopy and super-resolution techniques.

Light induced assembly and self-sorting of silica microparticles.

To tailor the properties of colloidal materials, precise control over the self-assembly of their constituents is a prerequisite. Here, we govern the assembly of silica particles by functionalization with supramolecular moieties which interact with each other via directional and reversible hydrogen bonding. Through a generally applicable synthesis protocol, two different types of self-complementary hydrogen bonding moieties, BTA- and UPy-derivatives, are anchored to silica particles.

Temperature-Induced, Selective Assembly of Supramolecular Colloids in Water.

In this article, we report the synthesis and physical characterization of colloidal polystyrene particles that carry water-soluble supramolecular ,',″,-trialkyl-benzene-1,3,5-tricarboxamides (BTAs) on their surface. These molecules are known to assemble into one-dimensional supramolecular polymers via noncovalent interactions. By tethering the BTAs to charge-stabilized particles, the clustering behavior of the resulting colloids was dictated by a balance between interparticle electrostatic repulsion and the BTA-mediated attractions.

Synthesis and Characterization of Supramolecular Colloids.

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs.

Stimuli-responsive colloidal assembly driven by surface-grafted supramolecular moieties.

A robust method is described for precisely functionalizing silica colloids with short-chain alkanes and self-associating o-nitrobenzyl protected benzene-1,3,5-tricarboxamides (BTAs). Controlled deprotection affords activation of the latent supramolecular moieties by facilitating short-range hydrogen-bonding interactions between surface-functionalized silica particles. Control of mesoscale assembly of the responsive colloidal suspensions is demonstrated with two different external triggers.

Nanopatterned superlattices in self-assembled C2 -symmetric oligodimethylsiloxane-based benzene-1,3,5-tricarboxamides.

The synthesis of C3 - and C2 -symmetric benzene-1,3,5-tricarboxamides (BTAs) containing well-defined oligodimethylsiloxane (oDMS) and/or alkyl side chains has been carried out. The influence of the bulkiness of the oDMS chains in the aggregation behavior of dilute solutions of the oDMS-BTAs in methylcyclohexane was studied by temperature-dependent UV spectroscopy. The formation of hierarchically self-assembled aggregates was observed at different BTA concentrations, the tendency of aggregation increases by shortening or removing oDMS chains.

Mechanistic control over morphology: self-assembly of a discotic amphiphile in water.

We report on the self-assembly of discotic amphiphiles that contain chelated gadolinium(iii) ions and are based on the C3-symmetrical benzene-1,3,5-tricarboxamide motif. Fluorescence spectroscopy, SAXS and cryo-TEM experiments demonstrate that a bimodal distribution of small and large aggregates is formed in a ratio that is dependent on the ionic strength. The results correlate with the previously reported degree of cooperativity of the polymerization mechanism, which increases with increasing NaCl concentration.

Tuning the aqueous self-assembly of multistimuli-responsive polyanionic peptide nanorods.

We report the pH and ionic strength triggered self-assembly of polyanionic dendritic peptide amphiphiles into well-defined nanorods in water; by establishing state diagrams we show how frustrated growth is used as a sensitive tool in order to manipulate and control the one-dimensional supramolecular polymerisation processes.

Controlling the size, shape and stability of supramolecular polymers in water.

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult. At the same time, the ability to do so is highly important in view of a number of applications in functional soft matter including electronics, biomedical engineering, and sensors. In the past, successful strategies to control the size and shape of supramolecular polymers typically focused on the use of templates, end cappers or selective solvent techniques.