Poly Methyl Methacrylate Glass Research Articles

A simple and economic method to modify large organic surfaces for enhancing adhesion and transparent Au/PMMA with high electromagnetic shielding efficiency

This study introduces a simple and cost-effective approach for modifying large organic surfaces, facilitating robust adhesion between Au films and polymethyl methacrylate (PMMA) while retaining transparency to visible light and effectively shielding against electromagnetic interference (EMI). The proposed surface modification method employs a cheap low-power conventional UV lamp to illuminate organic surfaces in an open environment, rending it convenient and applicable for surfaces ranging from small to massive, irrespective of size, shape and location. By subjecting transparent PMMA glass to a brief 20–30 min exposure to a 36 W UV lamp positioned 5 cm away from the sample surface, the PMMA surface is dramatically modified and the surface is turned from hydrophobic to hydrophilic, establishing a strong adhesion between PMMA and Au films. The resulting Au/PMMA glass exhibits remarkable transparency about 70% within the visible light spectrum, coupled with an impressive EMI shielding efficiency that surpasses 20 dB across a broad range of electromagnetic wavebands, encompassing the S, C, X and Ku bands that correspond to the wave frequencies of major electromagnetic pollution and crucial applications of 5G communication, credit card validation, radar systems, traffic control, etc. Various characterizations have been conducted, elucidating the underlying mechanisms. This study presents an important advancement, and the accessible and scalable nature of the large-scalable surface modification method has far-reaching implications across numerous industrial sectors and applications, in addition to transparent EMI shielding Au/PMMA glasses.

Influence of Novel SrTiO3/MnO2 Hybrid Nanoparticles on Poly(methyl methacrylate) Thermal and Mechanical Behavior.

While dental poly methyl methacrylate(PMMA) possesses distinctive qualities such as ease of fabrication, cost-effectiveness, and favorable physical and mechanical properties, these attributes alone are inadequate to impart the necessary impact strength and hardness. Consequently, pure PMMA is less suitable for dental applications. This research focused on the incorporation of Strontium titanate (SrTiO3-STO) and hybrid filler STO/Manganese oxide (MnO2) to improve impact resistance and hardness. The potential of STO in reinforcing PMMA is poorly investigated, while hybrid filler STO/MnO2 has not been presented yet. Differential scanning calorimetry is conducted in order to investigate the agglomeration influence on the PMMA glass transition temperature (Tg), as well as the leaching of residual monomer and volatile additives that could pose a threat to human health. It has been determined that agglomeration with 1 wt% loading had no influence on Tg, while the first scan revealed differences in evaporation of small molecules, in favor of composite PMMA-STO/MnO2, which showed the trapping potential of volatiles. Investigations of mechanical properties have revealed the significant influence of hybrid STO/MnO2 filler on microhardness and total absorbed impact energy, which were increased by 89.9% and 145.4%, respectively. Results presented in this study revealed the reinforcing potential of hybrid nanoparticles that could find application in other polymers as well.

Performance of a PV module with poly methyl methacrylate filter

Present PV modules (solar cells) costs higher than coal-fired electricity which is the baseline cost of today’s commercial power. To be utilized by Industry sector, the solar module’s price should be significantly reduced and solar energy efficiency is to be increased. This paper discusses a new innovation wherein the PV module’s efficiency can be increased by using selective irradiation of the sun light using Poly Methyl Methacrylate (PMMA) as IR filter. Experimental investigations are conducted on the silicon panel with different arrangement of with and without IR filter PMMA. It is reported that placing the PMMA glass on the panel reduced the operating temperature of the module and thus the power efficiency is found to be increased appreciably.

Nanopatterned PMMA-Yb:Er/Tm:Lu2O3 composites with visible upconversion emissions

Nanopillars, nanotubes and nanofibers of transparent polymethyl methacrylate (PMMA) polymer with Yb:Ln:Lu2O3 (Ln = Er or Tm) nanoparticles (NPs) (≈30–35 nm average size) have been prepared by infiltration of anodized aluminum oxide hexagonally nanopatterned templates. The outer diameter of these nanostructures is in the 330–400 nm range, with lengths up to 50 μm and a period distance of 430 nm. These nanostructures show visible upconversion (UC) emissions under excitation with 978 nm light. The steady state temperature of the polymer nanostructures is optically evidenced by the Er3+ UC emission and optically controlled around the PMMA glass transition temperature by the excitation light, introducing a new method for NP storage in a solid and potential optically induced particle release. Full color emission is shown in tridoped (Yb:Er:Tm) samples.

Ultrafast dynamics of Auramine O in composite films

Ultrafast excited-state dynamics of Auramine O, a diphenylmethane dye, in polymethylmethacrylate (PMMA) and in hybrid organic/inorganic sol–gel based films have been studied by means of femtosecond fluorescence upconversion experiments. The fluorescence transients of the samples showed a fast decay (few picoseconds) and a long decay (hundreds of picoseconds) representing a rapid cooling of the excess excitation energy to the matrices and the excited-state lifetime of the dye molecules, respectively. Different dynamic Stokes shifts in PMMA and hybrid glasses have been observed, which is argued to be ascribed to the different couplings between the emissive and nonemissive excited states for the two types of matrices.

Fatigue Damage Mechanism Analyses of Oriented Sheets of Polymethyl Methacrylate Glasses

To understand the damage mechanism and obtain the fatigue life of the oriented sheets of polymethyl methacrylate (PMMA) glasses, the quasi-static compression tests and the constant amplitude fatigue testing with two notch stress concentration factors are carried out respectively, using the CSS44100 electromechanical universal materials testing machines and a MTS servohydraulic testing machine. The damage region and fracture section of the deformed and failed sheet samples are examined with the aid of an optical microscopy. The results show that, 1) the oriented PMMA glasses drawn through vertical bi-direction have remarkable thermomechanical anisotropic characteristic, that is, it has the higher hardness and strength along the normal direction of the sheet panel, it will burst out and scatters into bigger pieces under the perforation; 2) the S-N curve of the oriented sheet specimens shows that its fatigue life is not sensitive on the notch at lower amplitude stress levels; and 3) the crack initiation of the oriented PMMA glasses often originates the interbeds area or mid region of the notch edge under fatigue cycle loading.

A compact package for integrated silicon thermal gas flow meters

An original packaging method suitable for integrated thermal mass flow sensors is presented. The method is based on a polymethyl-methacrylate (PMMA) adapter, used to convey the fluid flow to the chip areas where the sensing structures are located. Sealing of the adapter was obtained by heating the chip itself to the PMMA glass transition temperature, in order to soften the adapter front surface and improve adhesion. The proposed approach was applied to the packaging of thermal flow meters obtained by post-processing standard integrated circuits. The resulting compact devices have been characterized by measuring the response to a nitrogen flow. Fabrication and testing of a very compact flow sensor is described.

Kovacs effect in PMMA observed by low-frequency Raman scattering (boson peak)

The physical aging of the poly(methyl methacrylate) glass (PMMA) is described by its effects on the refractive index, that reflects the change of mean specific volume, and, on the other hand, on the low-frequency Raman scattering, i.e., on the boson peak. The boson peak depends mainly on the cohesion fluctuations. The memory or so-called Kovacs effect is observed by the appearance of a minimum of refractive index (i.e. a maximum of volume) as a function of the aging time at a higher temperature subsequent to an aging at lower temperature. The minimum of refractive index corresponds to a maximum of the boson peak intensity. However, the cohesion is not directly related to the volume, so that the evolution of the refractive index does not mimic exactly that of the boson peak intensity. Information on the change of cohesion by aging is obtained by enthalpy measurement. The obtained experimental results are discussed in the frame of the heterogeneous cohesion or elasticity at the nanometric scale. This clarifies the phenomenon of physical aging and the consequent Kovacs effect.

Femtosecond fluorescence studies of Auramine O in hybrid sol-gel derived films

ABSTRACTFemtosecond fluorescence upconversion experiments have been performed on Auramine O (a diphenylmethane dye) in polymethylmethacrylate (PMMA) and in hybrid organic/inorganic solgel based films.All the investigated samples showed a fast decay (few picoseconds) and a long decay (hundreds of picoseconds). The fast components are representative of the rapid cooling of the excess excitation energy to the matrices. The long components are representative of the excited-state lifetime of the probed molecules. Auramine O in solid matrices showed lifetimes longer than in liquid solutions. Torsional diffusion motions of the two phenyl rings of the molecule are held responsible for the excited-state dynamics.A dynamic Stokes shift has been observed for all samples. The lack of a rise time when detection was on the red side is explained in terms of an adiabatic coupling between emissive and nonemissive excited states, as is the case of liquid solutions. Different spectral shifts in PMMA and hybrid glasses have been measured. A different coupling between the emissive and nonemissive excited states for the two types of matrices is considered.

Notch strength and notch sensitivity of polymethyl methacrylate glasses

In this study, attempts are made to obtain the approaches for quantitatively evaluating the notch sensitivity and the notch strength of polymethyl methacrylate (PMMA) glasses. Tension tests show that the unoriented PMMA glass is a low-ductility material and the oriented PMMA glass is a high-ductility one, and the orientation of PMMA glass greatly increases the fracture ductility. The notch sensitivity of PMMA glasses can be evaluated by the so-called notch sensitivity factor, which can be predicted from tensile properties. Test results and analysis show that the notch strength of PMMA glasses can be expressed by the equation for notch strength and predicted from tensile properties for the notched elements of PMMA glass with any given stress concentration factor. The orientation of PMMA glass decreases the notch sensitivity and increases the notch strength. It should be noted that PMMA glasses have higher notch sensitivity and lower notch strength than those of ductile metals because of the very low-elasticity modulus of PMMA glasses. It also shows the possibility of predicting the failure criteria with given survivability for PMMA glass notched elements in this paper.

Properties and morphology of PMMA/ABN blends obtained via MMA in situ polymerisation through γ-rays

Methylmethacrylate polymerisation in the presence of 4 wt% butadiene-acrylonitrile rubber was carried out at fixed dose-rate and temperature. The effect of irradiation was investigated with respect to the mechanical and dynamic-mechanical properties in the solid state. A general increase of the “compatibilisation” on irradiation is obtained. In fact both rubber and polymethylmethacrylate glass transition temperatures, determined through dynamic-mechanical analysis, reveal the presence of strong interactions between the components. Furthermore an improvement of the mechanical tensile properties of the blends is observed when irradiation is continued after polymerisation, at least until a certain absorbed dose.

Dispersion of the optical constants of quartz and polymethyl methacrylate glasses in a wide spectral range: 0.2–3 μm

The optical constants, the absorption coefficients, and the Fermi energies of the quartz and the polymethyl methacrylate glasses are determined from the reflectance and the transmittance spectrograms of their slabs. These parameters are related to the Fresnel interface reflectance and transmittance by means of rigorous formulae taking into account the incoherent interference and the attenuation of light inside the slab. An iteration procedure is adopted in order to determine the Fresnel and the attenuation coefficients, which lead directly to the determination of the refractive index and the extinction coefficient. The dispersions of these two parameters are compared for the two given glasses inside two wide spectral windows bounded by two strong absorption bands at the extreme ultraviolet and infrared ends of the spectral range: 0.2–3 μm.

Microstructuring of Silica and Polymethylmethacrylate Glasses by Femtosecond Irradiation for MEMS Applications

AbstractWe report the fabrication of complex 3D microstructures in silica and polymethyl- methacrylate glass by a combination of femtosecond laser microfabrication and chemical wet etching techniques. It is demonstrated that fabrication of interconnected network of channels having lengths of about 200 νm, and diameters as small as 10 νm is possible due to the enhanced etching selectivity (typically 20 - 60) in the laser-irradiated regions. Thus, it becomes feasible to form 3D micro-fluidic and photonic crystal structures in transparent glass-like materials using this approach. In addition, preliminary results on microstructuring of rubber are presented.

Phosphorescence of benzaldehyde in a porous glass-polymethyl methacrylate matrix

The phosphorescence of benzaldehyde in a porous glass-polymethyl methacrylate matrix at a temperature T=77 K is investigated. The spectral and kinetic characteristics of the phosphorescence of benzaldehyde in such matrices differ significantly from those for benzaldehyde in polymethyl methacrylate alone. In addition, these characteristics depend on the type of porous glass used. The results are attributed to the interaction of benzaldehyde molecules with the pore walls.

Curing of a silane coupling agent and its effect on the transverse strength of autopolymerizing polymethylmethacrylate—glass fibre composite

summary The aim of this study was to determine how curing γ‐methacryloxypropyltrimethoxysilane (γ‐MPS) to the surface of E‐glass fibre affects the transverse strength of autopolymerizing polymethylmethacrylate–glass fibre composite (PMMA‐GF). For this purpose, unidirectional glass fibres treated with γ‐MPS solution and cured for various lengths of time at different temperatures (+50°C, +1OO°C and +150°C) were used as a strengthener of PMMA test specimens (n = 10 per group). The mean concentration of glass fibres in the test specimens was 17 wt%. The unreinforced test specimens and the test specimens reinforced with unsilanized fibres were compared, but no statistical difference in their transverse strengths was found (p = 0.568). The results also revealed that when the curing temperatures of the γ‐MPS were compared, the highest transverse strength (152 MPa) for the PMMA‐GF composite was obtained by curing the MPS for 120 min at +100°C; the lowest strength (91 MPa) was obtained by polymerizing the MPS at +150°C (P<0.001). However, SEM photomicrographs taken from the interface of the glass fibre and PMMA showed that the fibre adhered equally well to the PMMA treated at +100°C or at +150°C. This suggests that reduction in transverse strength of composite test specimens is caused by other factors, for example, by improper impregnation of PMMA into the fibre bundle, rather than by inadequate adhesion.

Non-Newtonian Flow in Polymethyl Methacrylate Glass under Simple Shear Condition

Non-Newtonian Flow in Polymethyl Methacrylate Glass under Simple Shear Condition

EPR studies of the excited triplet states of C60O and C60C2H4N(CH3) fullerene derivatives and C70 in toluene and polymethylmethacrylate glasses and as films

Abstract The EPR spectra of excited triplet states of two fullerene derivatives, C60O and C60C2H4N(CH3), in the glassy matrices of toluene and of polymethylmethacrylate (PMMA) and as films were examined at low temperature and the magnetic parameters were measured. In films, species with zfs parameters smaller than those in toluene were found and they were assigned to triplet excitations visiting more than one molecule in the crystallites that form the film. When C60C2H4N(CH3) was excited in PMMA grown by in sity thermal polymerization a new triplet species was originated characterized by a dipolar splitting constant D about three times larger than that measured in toluene. Evidence was gained that such species participates to cross-linking in the polymer. The effect of PMMA matrix on the molecular dynamics of 3C70 was also investigated. It was found that a dynamical model holds based on the pseudorotation of the molecule around the axis of larger dipolar splitting. Motion is activated with activation energy of 210 ± 50 cm−1 a value comparable with that obtained for pseudorotation of 3C70 in cyclohexane.

Plastic Deformation Mechanism in PMMA under Creep Stress

A rate analysis applied to the plastic flow under creep stress in glassy polymethyl methacrylate (PMMA) is presented. This analysis leads to the conclusion that the structure of the PMMA glass is changed into liquidlike structures during the large deformation under creep stress. Comparisons of various mechanical data obtained from the creep experiment for the polymer with those from the constant-rate deformation experiment indicate that the process of the glass-to-liquid structural change is controlled by the strain and strain rate being imposed on the polymer almost independently of the loading modes.

Superradiant film laser operation in red perylimide dye doped silica—polymethylmethacrylate composite

A new composite silica—polymethylmethacrylate glass material has been synthesized and doped by red perylimide dye ROT 300. Film coatings on ordinary glass plates were prepared. With second harmonic Nd:YAG laser pumping, such a structure exhibits laser properties when the emitted light is trapped and propagates in the supporting glass plate, producing a lasing effect at 623 nm with ≈0.1 mJ threshold and about 9 nm spectral bandwidth (but 70 nm for spontaneous emission). A significant amplification could be attributed to multiple inward total reflections of emitted light within the excited zone near to critical support-film boundary angles, while the emission from excited molecules within the film is stimulated by either evanescent wave propagation along the boundary, or by resonant energy coupling of waves propagating inside the support waveguide to leaky modes propagating inside the active film.

Rheology of the yielding in polymer glasses

Post‐yield plateau of a true‐stress versus strain relation for glassy polymethyl methacrylate (PMMA) is illustrated to be a state of steady flow. A novel rate analysis applied to this steady flow provided a unique functional relation between the activation energy ΔH and the activation entropy ΔS. This functional relation for the PMMA glass is demonstrated to agree with a function of ΔH vs ΔS obtained from the relaxation data for the melt of the same PMMA sample. This agreement was also confirmed for polyvinyl chloride, polycarbonate, and polystyrene, thus giving direct evidence verifying a change of the metastable glassy structure into a liquid‐like structure in the polymer glasses. Hence, the yielding in the polymer glasses is convincingly concluded to be a transition phenomenon due to this structural change.