The effect of annealing on the local structure of glassy polycarbonate

Annealing of polycarbonate glasses at temperatures belowTg leads to an increase in yield stress and a drop in the impact strength. Although such behaviour may be related to the corresponding reduction in free volume upon annealing, variations in the wide-angle X-ray scattering curves indicate some modification to the local structure. The area of an intrachain peak at s ∼ 0.7 Å−1 is monitored with respect to annealing temperature and time. It is proposed that the variations may be described by an increasing level of interlocking or (nesting) between neighbouring chain segments, a process which is a natural consequence of the molecular shape of polycarbonate.

Effects of gamma radiation on the photoluminescence properties of polycarbonate matrices doped with terbium complex

Luminescent films containing terbium complex [Tb(acac)(3)(H(2)O)(3)] (acac = acetylacetonate) doped into a polycarbonate (PC) matrix were prepared and irradiated at low-dose gamma radiation with ratio of 5 and 10 kGy. The PC polymer was doped with 5% (w/w) of the Tb(3+) complex. The thermal behavior was investigated by utilization of differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). Changes in thermal stability due to the addition of doping agent into the polycarbonate matrix. Based on the emission spectra of PC:5% Tb(acac)(3) film were observed the characteristic bands arising from the (5)D(4) -> (7)F(J) transitions of Tb(3+) ion (J = 0-6), indicating the ability to obtain the luminescent films. Doped samples irradiated at low dose of gamma irradiation showed a decrease in luminescence intensity with increasing of the dose. (C) 2009 Elsevier Ltd. All rights reserved.

Calorimetric investigations of luminescent films polycarbonate (PC) doped with europium complex [Eu(TTA)(3)(H(2)O)(2)]

Polymers doped with rare earth complexes are advantaged in film production for many applications in the luminescent field. In this luminescent polycarbonate (PC) films doped with diaquatris(thenoyltrifluoroacetonate)europium(III) complex [Eu(TTA)(3)(H(2)O)(2)] were prepared and their calorimetric and luminescent properties in the solid state are reported. The thermal behavior was investigated by utilization of differential scanning calorimetry (DSC) and thermogravimetry (TG). Due of the addition of rare earth [Eu(TTA)(3)(H(2)O)(2)] into PC matrix, changes were observed in the thermal behavior concerning the glass transition and thermal stability. Characteristic broadened narrow bands arising from the (5)D(0) -> (7)F(J) transitions (J = 4-0) of Eu(3+) ion indicate the incorporation of the Eu(3+) ions in the polymer. The luminescent films show enhancement emission intensity with an increase of rare earth concentration in polymeric matrix accompanied by decrease in thermal stability.

Using Polycarbonate Membranes as Templates for the Preparation of Au Nanostructures for Surface-Enhanced Raman Scattering

Polycarbonate membranes (PCM) of various pores sizes (400, 200, 100 and 50 nm) were used as templates for gold deposition. The electrodeposition from gold ions resulted in the formation of gold nanotubes when large pores size PCMs (400 and 200 nm) were used. On the other hand, gold nanowires were predominant for the PCMs with smaller pores size (100 and 50 nm). Surface-enhanced Raman scattering (SERS) from the probe molecule 4-mercaptopyridine (4-MPy) was obtained from all these nanostructures. The SERS efficiency of the substrates produced using the PC M templates were compared to two commonly used SERS platforms: a roughened gold electrode and gold nanostructures electrodeposited through organized polystyrene spheres (PSS). The SERS signal of the probe molecule increased as the pore diameter of the PCM template decreased. Moreover, the SERS efficiency from the nanostructures produced using 50 nm PCM templates was four and two times better than the signal from the roughened gold electrode and the PSS template, respectively. The SERS substrates prepared using PCM templates were more homogenous over a larger area (ca. 1 cm(2)), presented better spatial and sample to sample reproducibility than the other substrates. These results show that SERS substrates prepared using PCM templates are promising for the fabrication of planar SERS platforms for analytical/bioanalytical applications.

Polycarbonate (PC) membrane fouling by protein and sodium alginate

This data was obtained from an experiment, where polycarbonate (PC) membranes were used to filter two types of organic foulants, including protein and sodium alginate, from suspension in a dead-end filtration cell. These model foulants were stained with fluorescent dyes before filtration. Consequently, a stack of images were captured from the fouling layers on the PC membrane surface using confocal laser scanning microscope (CLSM). This data collection contains 105 2D images of polycarbonate (PC) membranes fouling layer. This data collection would be useful to investigate membrane fouling mechanism by membrane materials researchers and water researchers.

Polycarbonate (PC) membrane fouling by protein and yeast

This data collection contains 126 images of polycarbonate (PC) membranes fouling layer where two types of organic foulants including protein and yeast present.

This data collection would be useful to investigate membrane fouling mechanism by membrane materials researchers and water researchers.

Polycarbonate (PC) membrane fouling by yeast, protein and sodium alginate

This data collection contains 110 images of polycarbonate (PC) membranes fouling layer where three types of organic foulants including yeast, protein and sodium alginate present.

This data collection would be useful to investigate membrane fouling mechanism by membrane materials researchers and water researchers.

Evaluating backwashing efficiency of polycarbonate (PC) membrane fouled by protein and sodium alginate

This collection is the result of an investigation into the backwashing efficiency of polycarbonate (PC) membrane fouled by two types of organic foulants, protein and sodium alginate. In this experiement, polycarbonate (PC) membrane was used to filter those organic foulants from suspensions in a dead-end stirred cell. The organic foulants were stained with fluorescent dyes before filtration. After filtration, the PC membrane was backwashed. Consequently, a stack of images were captured from the fouling layers on the PC membrane surface using confocal laser scanning microscope (CLSM) and its associated image acquisition software. It contains image data of polycarbonate (PC) membranes' fouling layer when two types of organic foulants (protein and sodium alginate) are present. By comparing with the same membrane without backwashing, the efficiency of backwashing was computed. This data collection would be useful to researchers evaluating the backwashing efficiency of PC membrane in order to optimize frequency and operational conditions of backwashing by membrane materials researchers and by water..

Evaluating backwashing efficiency of polycarbonate (PC) membrane fouled by protein, sodium alginate and yeast

This collection is the result of an investigation into the backwashing efficiency of polycarbonate (PC) membrane fouled by three types of organic foulants, protein, sodium alginate and yeast. In this experiement, polycarbonate (PC) membrane was used to filter those organic foulants from suspensions in a dead-end stirred cell. The organic foulants were stained with fluorescent dyes before filtration. After filtration, the PC membrane was backwashed. Consequently, a stack of images were captured from the fouling layers on the PC membrane surface using confocal laser scanning microscope (CLSM) and its associated image acquisition software. It contains image data of polycarbonate (PC) membranes' fouling layer when three types of organic foulants (protein, sodium alginate and yeast) are present. By comparing with the same membrane without backwashing, the efficiency of backwashing was computed. This data collection would be useful to researchers who are evaluating the backwashing efficiency of PC membrane in order to optimize frequency and operational conditions of backwashing by membrane materials and by water..

Evaluating backwashing efficiency of polycarbonate (PC) membrane fouled by protein and yeast

This collection is the result of an investigation into the backwashing efficiency of polycarbonate (PC) membrane fouled by two types of organic foulants, protein and yeast. In this experiment, polycarbonate (PC) membrane was used to filter those organic foulants from suspensions in a dead-end stirred cell. The organic foulants were stained with fluorescent dyes before filtration. After filtration, the PC membrane was backwashed. Consequently, a stack of images were captured from the fouling layers on the PC membrane surface using confocal laser scanning microscope (CLSM) and its associated image acquisition software. It contains image data of polycarbonate (PC) membranes' fouling layer when two types of organic foulants (protein and yeast) present. By comparing with the same membrane without backwashing, the efficiency of backwashing was computed. This data collection would be useful to researchers evaluating the backwashing efficiency of PC membrane in order to optimize frequency and operational conditions of backwashing by membrane materials and by water.

Evaluating backwashing efficiency of polycarbonate (PC) membrane fouled by sodium alginate and yeast

This collection is the result of an investigation into the backwashing efficiency of polycarbonate (PC) membrane fouled by two types of organic foulants, sodium alginate and yeast. In this experiement, polycarbonate (PC) membrane was used to filter those organic foulants from suspensions in a dead-end stirred cell. The organic foulants were stained with fluorescent dyes before filtration. After filtration, the PC membrane was backwashed. Consequently, a stack of images were captured from the fouling layers on the PC membrane surface using confocal laser scanning microscope (CLSM) and its associated image acquisition software. It contains image data of polycarbonate (PC) membranes' fouling layer when two types of organic foulants (sodium alginate and yeast) present. By comparing with the same membrane without backwashing, the efficiency of backwashing was computed. This data collection would be useful to researchers evaluating the backwashing efficiency of PC membrane in order to optimize frequency and operational conditions of backwashing by membrane materials and by water..

Fabrication of polycarbonate microfluidic devices using a focusing and defocusing methods of CO2 laser system

Fabrication of microfluidic devices has always been a challenging endeavour due to its characteristics and cost involved. Recently, laser ablation using low cost engravers has been exploited for fast and cheap prototyping. In this paper, we explore the various parameters affecting the fabrication of polycarbonate microfluidic channels using CO2 laser ablation. The results show that, by manipulating the focus length of the laser beam, we can achieve good cross sectional profiles with low surface roughness. The results also show that various profiles can be fabricated by changing the laser parameters such as laser power, cutting speed and number of laser pulses.

Surface Modification of Polycarbonate by Atmospheric-Pressure Plasma Jets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spectroscopic properties of polycarbonate and poly(methyl methacrylate) blends doped with Europium(III) acetylacetonate

Spectroscopic properties of blends formed by bisphenol-A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) doped with Europium (III) acetylacetonate [Eu(acac)(3)], have been studied by photoacoustic spectroscopy (PAS) and photoluminescent (PL) spectroscopy. Emission and excitation spectra, excited state decay times, and quantum efficiency have been evaluated as well. PAS studies evidenced chemical interactions between the Europium complex and the PC/PMMA blend, which presented typical percolation threshold behavior regarding the Eu3+ content. PL spectra evidenced the photoluminescence of the Eu3+ incorporated into the blend. Photoluminescence property enhancement was observed for the composite in comparison with the precursor compound. Optimized emission quantum efficiency was observed for the 60/40 blend doped with 2% and 4% Europium (III) acetylacetonate. (c) 2005 Elsevier B.V. All rights reserved.

Treatment of polycarbonate by dielectric barrier discharge (DBD) at atmospheric pressure

Generally most plastic materials are intrinsically hydrophobic, low surface energy materials, and thus do not adhere well to other substances. Surface treatment of polymers by discharge plasmas is of great and increasing industrial application because it can uniformly modify the surface of sample without changing the material bulk properties and is environmentally friendly. The plasma processes that can be conducted under ambient pressure and temperature conditions have attracted special attention because of their easy implementation in industrial processing. Present work deals with surface modification of polycarbonate (PC) by a dielectric barrier discharge (DBD) at atmospheric pressure. The treatment was performed in a parallel plate reactor driven by a 60Hz power supply. The DBD plasmas at atmospheric pressure were generated in air and nitrogen. Material characterization was carried out by contact angle measurements, and X-ray photoelectron spectroscopy (XPS). The surface energy of the polymer surface was calculated from contact angle data by Owens-Wendt method using distilled water and diiodomethane as test liquids. The plasma-induced chemical modifications are associated with incorporation of polar oxygen and nitrogen containing groups on the polymer surface. Due to these surface modifications the DBD-treated polymers become more hydrophilic. Aging behavior of the treated samples revealed that the polymer surfaces were prone to hydrophobic recovery although they did not completely recover their original wetting properties.