Surface relief grating growth in thin films of mexylaminotriazinefunctionalized glass-forming azobenzene derivatives

Azobenzene-containing materials exhibit various photomechanical properties, including the formation of surface relief gratings (SRG) when irradiated with two interfering laser beams. In a recent study, a novel glass-forming derivative of Disperse Red 1 (DR1) with a mexylaminotriazine group was synthesized in high yield with a simple and efficient procedure, and showed the ability to form high-quality amorphous thin films with a high resistance to crystallization. Irradiation of films of this material yielded SRG with growth rates comparable to other reported azo materials. Herein, a series of closely related molecular glasses containing azobenzene chromophores with various absorption maxima ranging from 410 to 570 nm were synthesized, and their physical and photomechanical properties were studied. All materials studied showed the ability to form stable glassy phases, and irradiation with lasers emitting at various wavelengths allowed to perform a comparative study of SRG growth within a series of analogous chromophores.

Chemical Sensor Based on a Long-Period Fibre Grating Modified by a Functionalized Polydimethylsiloxane Coating

A chemical sensor based on a coated long-period grating has been prepared and characterized. Designer coatings based on polydimethylsiloxane were prepared by the incorporation of diphenylsiloxane and titanium cross-linker in order to provide enhanced sensitivity for a variety of key environmental pollutants and optimal refractive index of the coating. Upon microextraction of the analyte into the polymer matrix, an increase in the refractive index of the coating resulted in a change in the attenuation spectrum of the long-period grating. The grating was interrogated using ring-down detection as a means to amplify the optical loss and to gain stability against misalignment and power fluctuations. Chemical differentiation of cyclohexane and xylene was achieved and a detection limit of 300 ppm of xylene vapour was realized.

‘EXISTENCE AS RESISTANCE’: UNDERSTANDINGS OF IDENTITY, PLACE & BELONGING FOR YOUNG PALESTINIANS

In this thesis, I offer an exploration of what it means to be Palestinian, and constructions of identity, belonging and community, through drawing on the experiences of younger generations of Palestinians who have not lived in Palestine. This project seeks to investigate how understanding of our own individual, familial and community’s history plays in shaping our own understandings of identity, place, belonging and indigeneity, as a younger generation of Palestinians now living and studying in the diaspora. In particular, this project examined how the process of remembering and sharing memories in community act as a form of resistance to 68 years of settler colonial violence and erasure of Palestinian land and peoples, asking what our responsibilities this therefore entails from each and every one of us.

Instantaneous photoinduced patterning of an azopolymer colloidal nanosphere assembly

Colloidal azopolymer nanospheres assembled on a glass substrate were exposed to a single collimated laser beam. The combination of photo-fluidic elongation of the spherical colloids and light induced self-organization of the azopolymer film allows the quasiinstantaneous growth of a large amplitude surface relief grating. Pre-structuration of the sample with the nanosphere assembly supports faster creation of the spontaneous pattern. Confinement into the nanospheres provides exceptionally large modulation amplitude of the spontaneous relief. The method is amenable to any kind of photoactive azo-materials.

Malséance : la mort et l'image dans le (méta)théâtre de Samuel Beckett et de Jean Genet

Both ludic and macabre, the theatrical works of Samuel Beckett and Jean Genet are a paradox to behold. Indeed, as this thesis seeks to illustrate, despite their vastly differing aesthetics, at the core of each playwright’s stage productions is a tension between the characters’ yearning for silence and invisibility, and the continual creation of an often humorous, chaotic, exaggerated or theatrical image that depicts this very longing. Seeking an impossible intersection between their image and their death, they are trapped in a double bind that guarantees aesthetic failure. In order to grasp the close, yet delicate, relationship between the image of death and the death of the image, as presented in the plays of Beckett and Genet, we will explore how the characters’ creative processes deflate the very images — both visual and auditory — that they create. More specifically, we will examine how mimesis both liberates and confines the characters; while the symbolic realm provides the only means of self-representation, it is also a source of profound alienation and powerlessness, for it never adequately conveys meaning. Thus, body, gesture, language and voice are each the site of simultaneous and ceaseless reappearance and disappearance, for which death remains the only (aporetic) cure. Struggling against theatrical form, which demands the actors’ and the audience’s physical presence, both playwrights make shrewd use of metatheatre to slowly empty the stage and thereby suggest the impending, yet impossible, erasure of their characters.