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May 26 – 31, 2024
Western University
America/Toronto timezone
Welcome to the 2024 CAP Congress Program website! / Bienvenue au siteweb du programme du Congrès de l'ACP 2024!

(G) Elastic Modulus of Stable Polystyrene Glasses

May 27, 2024, 4:45 PM
15m
PAB Rm 106 (cap. 96) (Physics & Astronomy Bldg., Western U.)

PAB Rm 106 (cap. 96)

Physics & Astronomy Bldg., Western U.

Oral not-in-competition (Graduate Student) / Orale non-compétitive (Étudiant(e) du 2e ou 3e cycle) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) (DCMMP) M3-6 Soft Condensed Matter III | Matière condensée molle III (DPMCM)

Speaker

Ms Mahnoor Mehmood (University of Waterloo, ON, Canada)

Description

We are studying stable polystyrene (PS) glasses prepared by PVD (physical vapour deposition) with N up to ~12. These glasses have fictive temperatures as low as Tg -20 K with respect to its supercooled liquid line, and a kinetic stability of down to deposition temperatures of ~ 0.84*Tg. Employing increased surface dynamics, vapour deposition can yield an effectively packed amorphous material in a layer-by-layer pattern. In our lab, recently we have started determining the elastic modulus of PS films via atomic force microscopy (AFM). We examined the elastic modulus of PS, with a film thickness of ~ 100 nm, as a function of Mn (i.e., 11,200, 60,000 and 214,000 kg/mol), if the molecular size impacts the mechanical properties of the PS films. We observed a decrease in the magnitude of elastic modulus for PS as moving down to lower Mn. We also studied PS film with Mn = 214,000 kg/mol as a function of annealing time, annealed at the temperature of Tg + 20 K. The non-destructive nature of AFM allows us to determine the moduli of as-deposited glass, the supercooled liquid, and ordinary glass from a single sample. We will explore the mechanical properties of stable polymer vapour-deposited glasses of PS as a function of stability (down to Tg – 20 K) and the film thickness (50 nm – 200 nm). We expect to observe an increase in the elastic modulus (i.e., 20 - 30%) of the stable polymer vapour deposited glasses of PS compared to the ordinary glass of PS with the same N.

Keyword-1 Polystyrene Stable Glasses
Keyword-2 Youngs' Modulus
Keyword-3 polymer

Primary author

Ms Mahnoor Mehmood (University of Waterloo, ON, Canada)

Presentation materials

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