Polymer sensitivity

The wavelength range for which each polymer undergoes photodimerization, the wavelength at which each polymer displays maximal sensitivity, and the sensitivity (E the minimum incident input energy per unit area required to produce an insolubilized film of the same thickness as the the initial film) are listed in Table I. Polymer sensitivities were determined for the wavelength where each polymer displays maximum sensitivity. All formulations employed the same spinning solvent and the same developer. 

In addition to optimization of molecular structures, small variations in the assay operation conditions can also induce similar effects for improved polymer-sensitized dye emission [40], For instance, introduction of organic solvent into buffer can discourage PET owing to decreased dielectric constant of the solvent... 

Pu KY, Liu B (2009) Optimizing the cationic conjugated polymer-sensitized fluorescent signal of dye labeled oligonucleotide for biosensor applications. Biosens Bioelectron... 

Estimates of oCbiend using a rule-of-mixtures relationship are 3.0 X 102 and 7.2 X 103 cm lor 0.2 and 5.0% polyimide, respectively. This dependence of the optimum absorption coefficient (in terms of ablation rate), OVx on fluence is consistent with the observations of Chuang et al.6% for ablation of several UV-transparent (at 308 nm) polymers sensitized with low-molecular-weight dopants, e.g., PMMA doped with pyrene. For the pyrene-PMMA system, Chuang et al.6S reported maximum etch rates for 1.2 J/cm2 at a = 7 X 102 cm 1. It should not be expected that different dopant-matrix systems would yield the same optimum absorption coefficient for a given fluence level since the thermal properties for different polymers may vary significantly. 

Polymeric micelles are mostly small (10-100 nm) in size and dmgs can be incorporated by chemical conjugation or physical entrapment. For efficient delivery activity, they shonld maintain their integrity for a sufficient amount of time after injection into the body. Most of the experience with polymeric micelles has been obtained in the field of passive targeting of anticancer drugs to tumours [33]. Attachment of antibodies or sugars, or introduction of a polymer sensitive to variation in temperature or pH has also been stndied [32]. 

The incorporation of small percentages (<10%) of 3-oximino-2-butanone methacrylate (4) into poly(methyl methacrylate) (PMMA) (Scheme I) results in a four fold increase in polymer sensitivity in the range of 230-260 nm flO.l 11. Presumably, the moderately labile N-O bond is induced to cleave, leading to decarboxylation and main chain scission (Scheme II). The sensitivity is further enhanced by the addition of external sensitizers. Also, preliminary results indicated that terpolymerization with methacrylonitrile would effect an additional increase. These results complement those of Stillwagon (12) who had previously shown that copolymerization of methyl methacrylate with methacrylonitrile increased the polymer s sensitivity to electron beam irradiation. The mole fraction of the comonomers was kept low in order to insure retention of the high resolution properties of PMMA (3.41. 

Table II. The Effect of Maleic Anhydride (MA) and the Methyl Half-Ester of Maleic Acid (MM) on Alphamethylstyrene (AMS) Polymer Sensitivity...

Keywords Intramolecular cross-linking Nanogels Radiation cross-linking Responsive polymers Sensitive microgels... 

The first step for the development of polymers sensitive to 308-nm irradiation was the designing of various photolabile compounds for physical doping (solvent mixing) of polymers [117, 118]. The best results have been achieved by using triazene (-N=N-N-) or pentazadiene compounds (-N=N-N(R)-N=N-). The n-n transition of the -N=N-X- chromophore is located around 300 nm [119]. 

Although we cannot give a detailed interpretation of these results at the present, the short-lived chemiluminescence seen after short-term exposure of polymer-sensitizer films suggested that we were observing the decay of free radicals formed during the irradiation process. The ESR spectrum of a benzene solution containing trans-polypentenamer and dibenzanthrone and a film prepared from the solution, both displayed a... 

H. Liang, X. Li, Visible-induced photocatal34ic reactivity of polymer-sensitized titania nanotube films . Applied Catalysis B Environmental, 86, 8-17, (2009). 

To test this novel architecture as a tool for classification, a simulated experiment was performed. The case of chemo-resistive sensors was considered because of the simple involved electronics. This class of sensors is rather wide and can include sensors based either on inorganic (e.g. metal-oxide semiconductors) or organic (e.g. conducting polymers) sensitive materials. The concepts here illustrated can be extended, with a proper modification of the AORN architecture, to different kinds of chemical sensors. Actually, the features of the olfactive epithelium define the following structure of the AORN. 

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