Intercalated soft-crystalline mesophase exhibited by an unsymmetrical twist-bend nematogen

A number of new states of matter have been reported in recent years for liquid crystal dimers, most notably the twist-bend nematic phase which exhibits spontaneous breaking of symmetry through the emergence of chiral structures in an achiral fluid. In this communication we report on an unsymmetrical liquid crystal dimer that exhibits a transition from the spontaneously chiral twist-bend nematic phase into a novel smectic liquid crystal phase

Progression from nano to macro science in soft matter systems: : dimers to trimers and oligomers in twist-bend liquid crystals

In this article we report on the characterization and properties of several unsymmetrical phenyl-benzoate bimesogens that exhibit the soft-matter, twist-bend nematic (NTB) phase. We use this study as a basis to examine the phase behaviour of associated novel trimeric and tetrameric materials, in order to investigate the potential for oligomeric materials to form the NTB phase. Based on our results we hypothesise that higher oligomers and even polymers are highly likely to exhibit the NTB phase, provided they retain a gross bent structure between consecutive mesogenic units. Thus we show at the level of nanoscale organization, dimers can template with respect to one another to form mesophases that are also found in macromolecular systems

Order Parameters, Orientational Distribution Functions and Heliconical Tilt Angles of Oligomeric Liquid Crystals

We compare the order parameters, orientational distribution functions (ODF) and heliconical tilt angles of the TB phase exhibited by a liquid-crystalline dimer (CB7CB) to a tetramer (O47) and hexamer (O67) by SAXS/WAXS. Following the N-TB phase transition we find that all order parameters decrease, and while 〈P2 〉 remains positive 〈P4 〉 becomes negative. For all three materials the order parameter 〈P6 〉 is near zero in both phases. The ODF is sugarloaf-like in the nematic phase and volcano-like in the TB phase, allowing us to estimate the heliconical tilt angle of each material and its thermal evolution. The heliconical tilt angle appears to be largely independent of the material studied despite the differing number of mesogenic units

Two poems, 'The Ghost Walks' and 'A bell on every tooth', .

Two poem

“Through My Dream”: Trevor Joyce’s Translations

Almost all Irish translators work with what Lawrence Venuti calls a “domesticating” model of recreating a translated poem as if it had been originally written in the target language. However, some of the most important Irish translators of the past, notably James Clarence Mangan and Brian Coffey, have used what Venuti terms a “foreignizing” strategy which, on the contrary, highlights the difficulties and resistances of the source text to transparent re-presentation. The two approaches roughly correspond to two modes of translation evident in the work of the most influential anglophone poetry translator of the early twentieth century, Ezra Pound. In his translation of the Buile Suibhne as the Poems of Sweeny Peregrine (1976), which cites Poundian precedent, the contemporary Irish neo-modernist poet Trevor Joyce (b. 1947) uses both modes to produce a destabilised, postmodern “working” which exploits the original’s gaps, scribal interpolations and narrative contradictions, as well as poignantly rendering its expressivist lyrics. Radical translation strategies can be seen to inform other aspects of Joyce’s work, from his use of Japanese and Chinese forms and materials in Stone Floods (1995), to cut-up and collage in Trem Neul (2000), and from folk-song and poetry from the Finno-Ugric, Hungarian and Irish in What’s in Store (2007) and Courts of Air and Earth (2008) to, most recently, the unpublished Rome’s Wreck, which “translates” Edmund Spenser’s “The Ruines of Rome” (1591) “intralingually”, to use Roman Jakobson’s term, that is, from one form of English into another.Presque tous les traducteurs irlandais travaillent à partir d’un modèle que Lawrence Venuti appelle « domesticating translation ». Ils tentent de recréer le poème comme s’il avait été écrit dans la langue cible. Cependant, certains parmi les plus grands traducteurs irlandais du passé, notamment James Clarence Mangan et Brian Coffey, ont utilisé une stratégie que Venuti appelle « foreignizing translation » qui, à l’opposé, souligne les difficultés et les résistances que le texte source oppose à une représentation transparente dans le texte cible. Ces deux approches correspondent en gros à deux modes de traduction visibles dans le travail d’Ezra Pound, le poète-traducteur anglophone qui a exercé le plus d’influence au début du xxe siècle. Dans sa traduction de Buile Suibhne, The Poems of Sweeny Peregrine (1976), qui cite le précédent poundien, le poète neo-moderniste irlandais Trevor Joyce (né en 1947) se sert des deux modes pour produire une version déstabilisée et postmoderne du texte source, qui exploite les blancs, les interpolations du scribe et les contradictions narratives, tout en traduisant de manière intense l’expressivisme de l’original. Des stratégies radicales de traduction ont également influencé d’autres aspects du travail de Joyce, de son utilisation de formes et de sources japonaises et chinoises dans Stone Floods (1995) à sa technique du coupé-collé dans Trem Naul (2000), et de son utilisation du chant folklorique et de la poésie d’origine finno-ougrienne, hongroise et irlandaise dans What’s in Store (2007) et Courts of Air and Earth (2008) à son travail récent Rome’s Wreck (non encore publié) qui « traduit » « The Ruines of Rome » (1591) d’Edmund Spenser de façon “intralinguale’ (terminologie de Roman Jakobson), c’est à dire d’une forme de la langue anglaise vers une autre

Molecular shape as a means to control the incidence of the nanostructured twist bend phase

Liquid crystalline phases with a spontaneous twist-bend modulation are most commonly observed for dimers and bimesogens with nonamethylene spacers. In order to redress this balance we devised a simple chemical intermediate that can be used to prepare unsymmetrical bimesogens; as a proof of concept we prepared and studied eleven novel materials with all found to exhibit the twist-bend phase and exhibit a linear relationship between TN-I and TTB-N. A computational study of the conformational landscape reveals the octamethyleneoxy spacer to have a broader distribution of bend-angles than the nonamethylene equivalent, leading to reductions in the thermal stability of the TB phase. This result indicates that a tight distribution of bend-angles should stabilise the TB phase and lead to direct TB-Iso phase transitions, and conversely a broader distribution should destabilise the TB phase which may allow new states of matter that are occluded by the incidence of this phase to be revealed

An experimental and computational study of calamitic and bimesogenic liquid crystals incorporating an optically active [2,2]-paracyclophane

Two liquid-crystalline materials containing an optically active (R)-4-hydroxy-[2,2]-paracyclophane group were prepared, one in which the chiral group is a bulky terminal unit and one in which it forms part of a terphenyl-like mesogenic unit. Both materials exhibit monotropic chiral nematic phases. Partial phase diagrams were constructed for mixtures of both materials with 5CB, allowing us to extrapolate pitch lengths and helical twisting power values (HTP) for each material. The HTP value of the material with a ‘locked’ paracyclophane is 70% higher than that of a ‘free’ paracyclophane and this is rationalised as being due to the reduction in conformational freedom of the former material relative to the later

A Nematic to Nematic Transformation Exhibited by a Rod-Like Liquid Crystal

A novel, highly polar rod-like liquid crystal was found to exhibit two distinct nematic mesophases (N and Nx). When studied by microscopy and X-ray scattering experiments, and under applied electric fields, the nematic phases are practically identical. However, calorimetry experiments refute the possibility of an intervening smectic mesophase, and the transformation between the nematic phases was associated with a weak thermal event. Analysis of measured dielectric data, along with molecular properties obtained from DFT calculations, applying the Maier-Meier relationship allowed for the degree of antiparallel pairing of dipoles in both nematic phases to be quantified. Based on the results, we conclude that the onset of the lower temperature phase is driven by the formation of antiparallel molecular associations

Evaluation of 4-alkoxy-40-nitrobiphenyl liquid crystals for use in next generation scattering LCDs

We have prepared nine members of the 4-alkoxy-40-nitrobiphenyl family of liquid crystals and evaluated their thermal behaviour by a combination of polarised optical microscopy, differential scanning calorimetry and small angle X-ray scattering, as well as in single pixel scattering devices for use in backlight free liquid crystal displays (LCDs). Whereas homologues with shorter terminal aliphatic chains are nematogenic, those with longer aliphatic chain lengths exhibit an additional smectic A phase, identified as the subtype SmAD by SAXS with all materials having a D/L ratio (smectic layer spacing divided by molecular length) of 1.4. When doped with 0.1 wt% hexadecyltrimethylammonium perchlorate we observed that the SmAD phase of compound 9 could be switched with a relatively low voltage (58 VRMS, roughly half that required for the analogous nitrile). This apparent reduction in threshold voltage, which occurs as a consequence of switching from a nitrile- to a nitro- group, provides a new impetus to study alternative polar terminal groups when designing host materials for smectic A scattering devices