Lucebert : «as alles» [cendre tout]

Lucebert (1924-1994) est la figure la plus importante de ce qu’il est convenu d’appeler le Mouvement de Cinquante et qui a profondément transformé la poésie néerlandaise de l’après-guerre. Cet article traite de quelques poèmes christiques.Dans ses premières œuvres où apparaît le Christ comme dans les plus récentes, Lucebert montre clairement que derrière son attaque contre le langage se cache une attaque contre Dieu. La vie et la mort du Christ sont interprétées par le poète comme autant de raisons pour mener un combat pour la parole, de même qu’il trouve dans les réalités historiques des années cinquante les fondements de la nécessité de créer une langue nouvelle. En s’appuyant sur l’intertexte de la mystique juive et de l’œuvre de Friedrich Hölderlin, il conçoit le projet d’une langue nouvelle qu’il concrétise dans de analphabetische naam [le nom analphabétique].Lucebert (1924-1994) is de belangrijkste vertegenwoordiger van de zogeheten Beweging van Vijftig, die de naoorlogse Nederlandse poëzie ingrijpend veranderd heeft. Dit artikel handelt over een aantal Christusgedichten van Lucebert. In zowel zijn vroege als zijn late gedichten over Christus maakt Lucebert duidelijk dat achter zijn aanval op de taal een aanval op God schuilt. De dichter interpreteert leven en sterven van Christus als reden voor een gevecht om de taal, zoals hij ook de historische werkelijkheid van circa 1950 begrijpt als grond voor de noodzaak om een nieuwe taal te scheppen. Gebruik makend van de intertekst van de Joodse mystiek en van het werk van Friedrich Hölderlin ontwerpt hij zijn programma voor een nieuwe taal, dat hij in de schepping van de analphabetische naam heeft geconcretiseerd

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

\u3cp\u3eA 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. First, the amount of active (i.e., deprotected) BTAs is efficiently tuned by varying the exposure time to UV radiation. Controlled activation of the BTAs translates to regulating the valence of the system. After activation, the binding strength of individual BTAs can be modulated with temperature, providing an additional handle with which the assembly behavior is manipulated. This dual-regulation approach is a powerful and sensitive avenue for controlling colloidal assembly processes.\u3c/p\u3

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. Chiral BTAs were investigated with circular dichroism (CD) spectroscopy, showing a stronger tendency to aggregate than the achiral ones. Majority rules experiments show a linear behavior consistent with the existence of a high mismatch penalty energy. The most efficient oDMS-BTAs organogelators have the ability to form stable organogels at 5 mg¿mL-1 (0.75 wt¿%) in hexane. Solid-state characterization techniques indicate the formation of an intermolecular threefold hydrogen bonding between adjacent molecules forming thermotropic liquid crystals, exhibiting a hexagonal columnar organization from room temperature to above 150¿°C. A decrease of the clearing temperatures was observed when increasing the number and length of the oligodimethylsiloxane chains. In addition to the three-fold hydrogen bonding that leads to columnar liquid crystalline phase, segregation between the oDMS and aliphatic chains takes place in the BTA functionalized with two alkyl and one oDMS chain leading to a superlattice within the hexagonal structure with potential applications in lithography

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 difficult1. 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 templates2,3, end cappers4 or selective solvent techniques5. Here we disclose a strategy based on self-assembling discotic amphiphiles that leads to the control over stack length and shape of ordered, chiral columnar aggregates. By balancing electrostatic repulsive interactions on the hydrophilic rim and attractive non-covalent forces within the hydrophobic core of the polymerizing building block, we manage to create small and discrete spherical objects6,7. Increasing the salt concentration to screen the charges induces a sphere-to-rod transition. Intriguingly, this transition is expressed in an increase of cooperativity in the temperature-dependent self-assembly mechanism, and more stable aggregates are obtained. For our study we select a benzene-1,3,5-tricarboxamide (BTA) core connected to a hydrophilic metal chelate via a hydrophobic, fluorinated L-phenylalanine based spacer (Scheme 1). The metal chelate selected is a Gd(III)-DTPA complex that contains two overall remaining charges per complex and necessarily two counter ions. The one-dimensional growth of the aggregate is directed by p-p stacking and intermolecular hydrogen bonding. However, the electrostatic, repulsive forces that arise from the charges on the Gd(III)-DTPA complex start limiting the one-dimensional growth of the BTA-based discotic once a certain size is reached. At millimolar concentrations the formed aggregate has a spherical shape and a diameter of around 5 nm as inferred from 1H-NMR spectroscopy, small angle X-ray scattering, and cryogenic transmission electron microscopy (cryo-TEM). The strength of the electrostatic repulsive interactions between molecules can be reduced by increasing the salt concentration of the buffered solutions. This screening of the charges induces a transition from spherical aggregates into elongated rods with a length > 25 nm. Cryo-TEM allows to visualise the changes in shape and size. In addition, CD spectroscopy permits to derive the mechanistic details of the self-assembly processes before and after the addition of salt. Importantly, the cooperativity -a key feature that dictates the physical properties of the produced supramolecular polymers- increases dramatically upon screening the electrostatic interactions. This increase in cooperativity results in a significant increase in the molecular weight of the formed supramolecular polymers in water

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 C-3-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. Hence, by tuning the electrostatic interactions between the ligands at the periphery we can tune the cooperativity of the self-assembly. This tunability provides a versatile handle to adjust the size and shape of the discotic amphiphiles, which have potential as supramolecular MRI contrast agents