SPECIFIC FEATURES OF POLYMETHYL METHACRYLATE COMBUSTION WITH AND WITHOUT TRIPHENYL PHOSPHATE ADDITIVES: INVESTIGATION BY LASER-INDUCED FLUORESCENCE AND COHERENT ANTI-STOKES RAMAN SPECTROSCOPY

The influence of triphenyl phosphate additives on the characteristics of flame propagation along a polymethyl methacrylate (PMMA) sample has been shown by laser-induced fluorescence and coherent anti-Stokes light scattering spectroscopy.

Piezoresistive Ring-Shaped AFM Sensors with Pico-Newton Force Resolution

A new concept of Atomic Force Microscope (AFM) oscillating probes using electrostatic excitation and piezoresistive detection is presented. The probe is characterized by electrical methods in a vacuum chamber and by mechanical methods in air. The frequency-mixing measurement technique is developed to reduce the parasitic signal level. These probes resonant in the 1MHz range and the quality factor is measured about 53000 in vacuum and 3000 in air. The ring probe is mounted onto a commercial AFM set-up and the surface topography of PMMA sample (2 µm square) is obtained. The force resolution deduced from the measurements is about 10 pN/Hz0.5.

Three Dimensional Surface Patterning Atop Poly(methyl Methacrylate) (PMMA)

We demonstrate a novel approach to fabricate three dimensional (3-D) surface patterns atop poly(methyl methacrylate) (PMMA). This approach utilizes both shape recovery behavior and swelling phenomenon of the PMMA. The simplicity in the fabrication process affirms the low-cost nature of this approach. Moreover, as obtained 3-D patterned PMMA sample can be used as artificial compound eye.

The Calculation and Experimental Research on the Properties of Reflectance of Methyl Red Doped Polymer

The reflection spectrum of Methyl Red (MR) doped PMMA film is measured and modified. The refractive index of the sample is gained by calculation of Kramers- Kronig relation with the data of the reflection spectrum. The refractive index change of the sample is gained with the absorption specta. The MR doped PMMA sample has a refractive index change under 532nm laser excitation, in which the valley value happens around 400 nm and peak value around 600 nm. This result shows that the MR doped PMMA sample has an obvious photo induced refractive index change, especially at 400nm and 600nm.

Nanoindentation of Vacuum Ultraviolet Light-Irradiated Poly(methylmethacrylate) Substrates

ABSTRACTSurface modification of poly(methylmethacrylate) (PMMA) substrates has been demonstrated using an excimer lamp radiating vacuum ultraviolet (VUV) light of 172 nm in wavelength. In this study, we have particularly focused on the effects of atmospheric pressure during VUV irradiation. Each of the substrates was photoirradiated with VUV light under a pressure of 10, 103 or 105 Pa. Changes in nanomechanical properties of the VUV-irradiated sample surfaces were studied based on a scratching test using a nanoindenter. The wear-depth of the PMMA sample treated at 105 Pa was about 137.0 nm, which was much larger than the wear-depth of an untreated PMMA substrate (63.3 nm). On the contrary, when samples were prepared with VUV irradiation conducted at 10 and 103 Pa, their wear-depths markedly decreased down to about 2.2 and 12.5 nm, respectively. The sample treated at 10 Pa was particularly wear-resistant. This high wear-resistance was attributable to the formation of new carbon-carbon bonds such as C=C bonds on the PMMA surfaces.