Polyimides optical

Cold phosgenation, 222 Color contamination, 541 Colorless polyimides, optical properties of, 277-279... 

We attempted to use this increase in refractive index in fabricating polyimide optical waveguides. The fabrication of a fluorinated polyimide waveguide by the direct electron beam writing method is described in Section 4.3.2. We also investigated the changes in the refractive index of fluorinated polyimide films by synchrotron radiation. 7 The refractive index at a wavelength of 589.6 nm increased by 1.3% and the thickness decreased by 0.69% for fluorinated polyimide film after 30 min of synchrotron irradiation. From the XPS data the synchrotron radiation leads to production of a fluorine-poor surface. 

The refractive index of fluorinated polyimide can be controlled precisely by adjusting the election beam irradiation dose as described in Section 3.2.2, and this feature can be exploited in fabricating polyimide optical waveguides. This section describes fluorinated polyimide waveguides fabricated by the direct electron beam writing method. ... 

Thermoplastic polyester-silicone polyimide - Optical and electrical application - [44]... 

Other Polymers. Besides polycarbonates, poly(methyl methacrylate)s, cycfic polyolefins, and uv-curable cross-linked polymers, a host of other polymers have been examined for their suitabiUty as substrate materials for optical data storage, preferably compact disks, in the last years. These polymers have not gained commercial importance polystyrene (PS), poly(vinyl chloride) (PVC), cellulose acetobutyrate (CAB), bis(diallylpolycarbonate) (BDPC), poly(ethylene terephthalate) (PET), styrene—acrylonitrile copolymers (SAN), poly(vinyl acetate) (PVAC), and for substrates with high resistance to heat softening, polysulfones (PSU) and polyimides (PI). 

Relatively few processible polyimides, particularly at a reasonable cost and iu rehable supply, are available commercially. Users of polyimides may have to produce iutractable polyimides by themselves in situ according to methods discussed earlier, or synthesize polyimides of unique compositions iu order to meet property requirements such as thermal and thermoxidative stabilities, mechanical and electrical properties, physical properties such as glass-transition temperature, crystalline melting temperature, density, solubility, optical properties, etc. It is, therefore, essential to thoroughly understand the stmcture—property relationships of polyimide systems, and excellent review articles are available (1—5,92). 

Since the end of the 1970s, the polyimides have been introduced for the production of electronic components mainly for the passivation. But more and more they are interesting for the integrated circuits and multichip modulus fabrications. Processability and dielectric and thermomechanical properties are the most attractive features of these materials for the electronic31 and electro-optical applications.32... 

Electron microscopy, 163-164 Electro-optic applications, polyimide, 269 Electrophilic aromatic substitution, 329-334, 398... 

Optical properties, of colorless polyimides, 277-279 Optical rotation, 490 Opto-electronic targets, 271-272 Organic phase-soluble aromatic polyesters, 77... 

Phthalazinone, 355 synthesis of, 356 Phthalic anhydride, 101 Phthalic anhydride-glycerol reaction, 19 Physical properties. See also Barrier properties Dielectric properties Mechanical properties Molecular weight Optical properties Structure-property relationships Thermal properties of aliphatic polyesters, 40-44 of aromatic-aliphatic polyesters, 44-47 of aromatic polyesters, 47-53 of aromatic polymers, 273-274 of epoxy-phenol networks, 413-416 molecular weight and, 3 of PBT, PEN, and PTT, 44-46 of polyester-ether thermoplastic elastomers, 54 of polyesters, 32-60 of polyimides, 273-287 of polymers, 3... 

Figure 8. TEM and optical absorption of the sample implanted with 5 x 10 Au /cm (a) TEM cross-sectional micrograph (dashed lines represent the free surface and film-substrate interface) (b) nanoparticles size distribution (c) simulated optical spectra (1) Au cluster in a non-absorbing medium with n = 1.6 (2) Au cluster in polyimide (absorbing) (3) Au(core)-C(shell) cluster in a nonabsorbing medium with n = 1.6 (4) the experimental spectrum of Au-implanted polyimide sample, (d) X-ray diffraction patterns as a function of the implantation fiuence.

Figure 17. Optical absorption spectra of the polyimide implanted with 5x 10 Au m in presence of dry air and of methanol vapor (6000 ppm). Inset optical absorption difference calculated taking into account both spectra. (Reprinted from Ref. [68], 2005, with permission from Elsevier.)...

Figure 18. Dynamical optical absorption responses for (a,c) the polyimide film implanted with 5 x 10 Au /cm and for (b,d) the virgin film obtained upon different exposures to (a,b) methanol vapors (6000 ppm) or (c,d) to ethanol vapors (6000 ppm).

Although there have been great advances in covalent functionalization of fullerenes to obtain surface-modified fullerene derivatives or fullerene polymers, the application of these compounds in composites still remains unexplored, basically because of the low availability of these compounds [132]. However, until now, modified fullerene derivatives have been used to prepare composites with different polymers, including acrylic [133,134] or vinyl polymers [135], polystyrene [136], polyethylene [137], and polyimide [138,139], amongst others. These composite materials have found applications especially in the field of optoelectronics [140] in which the most important applications of the fullerene-polymer composites have been in the field of photovoltaic and optical-limiting materials [141]. The methods to covalently functionalize fullerenes and their application for composites or hybrid materials are very well established and they have set the foundations that later were applied to the covalent functionalization of other carbon nanostructures including CNTs and graphene. 

N.V. Kamanina, Mechanisms of optical limiting in p-conjugated organic system fullerene doped polyimide, Synthetic Metals, vol. 127, pp. 121-128, 2002. 

Optical properties of the material are less critical for microchips hyphenated with MS than for devices with on-chip optical detection where low background absorption or fluorescence is mandatory. Thus, completely opaque polymers like glassy carbon or polyimide " can be used as microfabrication substrates. Furthermore, polymer microchips are of great interest because their potentially low manufacturing costs may allow them to be disposable. Methods used for the fabrication of plastic chips include laser ablation and molding methods. 

Metal ion modified polyimide films have been prepared to obtain materials having mechanical, electrical, optical, adhesive, and surface chemical properties different from nonmodified polyimide films. For example, the tensile modulus of metal ion modified polyimide films was increased (both at room temperature and 200 0 whereas elongation was reduced compared with the nonmodif ied polyimide (i). Although certain polyimides are )cnown to be excellent adhesives 2) lap shear strength (between titanium adherends) at elevated temperature (275 0 was increased by incorporation of tris(acetylacetonato)aluminum(III) (2). Highly conductive, reflective polyimide films containing a palladium metal surface were prepared and characterized ( ). The thermal stability of these films was reduced about 200 C, but they were useful as novel metal-filled electrodes ( ). 

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