Decrease upon irradiation

In 1982, an azo-dye-containing copolymer of 2-hydroxymethyl methacrylate was used for modulation of lysozyme adsorption on polymer beads. The amount of the protein adsorbed on a microsphere decreased upon irradiation, but rather long... 

For both PI-1 and PX-2, assuming that n e (n, mean refractive index) for optical frequencies, the mean dielectric constant, (e) decreases upon irradiation (A pi = - 0.023, A pi 2 - - 0.016). The dielectric constant is proportional to the chromophore density and the decrease upon irradiation suggests a quasi-... 

Concerning the polymers, Irie and collaborators prepared a number of polyamides with azobenzene groups in the backbone (e.g., 21). The viscosity of the polyamides in a polar solvent decreased upon irradiation and returned to the initial value in the dark. 

Silver nanoparticles can be deposited on Ti02 by UV-irradiation. Deposition of polydisperse silver particles is a key to multicolor photochromism. The nanoparticles with different size have different resonant wavelength. Upon irradiation with a monochromatic visible light, only the resonant particle is excited and photoelectrochemically dissolved, giving rise to a decrease in the extinction at around the excitation wavelength. This spectral change is the essence of the multicolor photochromism. The present photoelectrochemical deposition/dissolution processes can be applied to reversible control of the particle size. 

During photolysis, the double bond content of the polysilane(P-l)(15mol% in this experiment) decreased to 10mol%, as measured by 1H-NMR spectroscopy. However, the ratio, quantum yield of scission(Q(S))/quantum yield of crosslinking(Q(X)), was not affected by the reaction of the double bond. West and his coworkers have reported that poly((2-(3-cyclohexenyl)-ethyl)methylsilane-co-methylphenylsilane) crosslinked upon irradiation(55). The difference between our results and West s may lie in the amount of the double bond and inhibitation of the radical closslinking by the phenol moiety. Polysilane with a halogen moiety, P-8, photodecomposed rapidly, compared with P-1 or P-3. The introduction of a chloride moiety was effective for the sensitization of the photodegradation. Similar results has already been reported(55). 

A photosensitive composition, consisting of an aromatic azide compound (4,4 -diazidodi-phenyl methane) and a resin matrix (poly (styrene-co-maleic acid half ester)), has been developed and evaluated as a negative deep UV resist for high resolution KrF excimer laser lithography. Solubility of this resist in aqueous alkaline developer decreases upon exposure to KrF excimer laser irradiation. The alkaline developer removes the unexposed areas of this resist. 

The influence of photoexcited fullerene C60 on viability of thymocytes, EAC, and L1210 cells was studied after 24 h of incubation, considering the content of viable cells at incubation as 100% (Table 6.1). After irradiation of fullerenes C60 in the cell medium, significant decrease in the content of viable cells in the suspension of thymocytes was not registered, whilst the number of viable malignant cells decreased. Upon the presence of photoexcited fullerene C60 in incubation medium, the number of viable EAC cells decreased by 20%, and L1210 by 12%, while in the... 

Likewise, the N derivatives of carbazoles undergo PFR [116-118], Upon irradiation in cyclohexane A-acetyl-carbazole (157) gives the following products (quantum yields in parentheses) [119] 1-acetylcarbazole (158) (0.10), 3-acetyl-carbozole (159) (0.09), and carbazole (160) (0.06) (Scheme 43). The analogous A-acetyldiphenylamine gives the ortho- and para-acetylated products along with diphenylaniline with quantum yields of 0.20,0.096, and 0.048, respectively [119], Table 10 shows that these values decrease from cyclohexane to ethanol, but less markedly than in the case of acetanilide (see Table 8). 

The decrease in absorbancy of poly U upon irradiation is discussed by Swenson and Setlow.48 Their results are shown in Figure 27. In this figure is also shown the photoinduced dimer splitting. The amount of photorecovery of absorbance for any particular total dose was taken to be a measure of the amount of dimer content at that dose. The amounts of dimer so calculated are shown in Figure 28. The amount of hydrates formed were estimated by measuring the thermal recovery of absorbancy. The results of both thermal and radiation reversal are shown in Figure 29. The total recovery of absorbance for poly U irradiated at 265 nm was 87-90% (after certain corrections, it was estimated that 95% of the absorbance decrease could be accounted for by dimers and hydrates). Of this total reversal of 907o about 67% was effected by the thermal treatment, and presumably this number provides an estimate of the total fraction (0.75) of hydrates in the photoproducts. 

Figure 2 compares ATR spectra of the irradiated and unirradiated sides of a cellulose triacetate film after 24-hour radiation at 253.7 min vacuum. The ATR spectrum of a control cellulose triacetate film, which is identical with that of the unirradiated side in Figure 2, is given in Figure 3. Figure 4 shows the change of infrared absorptions of a cellulose film cast on a NaCl plate upon irradiation at 253.7 min vaccum. The spectra were recorded at 90°C. An increase in OH (3 microns) and a decrease in carbonyl (5.7 microns) absorption were noted. 

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