Transmittance, poly solutions

The phase transition temperatures (lower critical solution temperature, LCST) of the pol5miers were obtained from the change in the transmittance of their aqueous solutions (Figure 1). The aqueous solution of the obtained pol5uner was prepared and its transmittance at 500 nm was monitored with increase in the ambient temperature. Both of poly-NIPA and poly-NEA showed a sudden decrease in the transmittance at 37.5 and 69.2 °C, respectively. The result shown in Figure 1 clearly suggests the thermosensitivity of the pol5mers, and the obtained LCST values are close to those reported for poly-NIPA (34.8 °C) [8] and poly-NEA (72 °C) [9]. 

Figure 1. Transmittance of the polymer solutions at 500 nm with increase in the ambient temperature. (A) poly-NIPA and (B) poly-NEA.

Similar photosolubility effects have been observed for azo-modified poly(L-omithine) [Scheme 5, VIII (n = 3) 139 and poly(L-a, 3-diaminopropanoic acid) [Scheme 5, VIII (n = 1), 142 monitoring transmittance at 650 nm as a function of irradiation time. The initially turbid samples in HFP/water became dear upon irradiation at 360 nm as a consequence of the trans—>ds isomerization. On new irradiation at 460 nm, the clear solutions became turbid once more as a consequence of the reverse cis/trans isomerization of the azo chromophores. 

Kyoumen, M. Baba, Y. Kagemoto, A., "Determination of Consolute Temperature of Poly[Styrene-ran- (Butyl Methacrylate)] Solutions by Simultaneous Measurement of Differential Thermal Analysis and Laser Transmittance," Macromolecules, 23, 1085 (1990). 

CEL solutions were obtained by dissolving poly(N-vinyl pyrrolidone) and a diazoniun salt (D2, D3 or D4) in aqueous acetic acid. The solutions were spin-coated on a conventional photoresist layer formed on a silicon wafer. CEL layers on quartz substrate were used for optical transmittance measurements. 

Fig. 30. Transmittance changes at 750 nm of a 1 % aqueous solution of poly(7V-isopropylacrylamide) with pendant azobenzene groups (2.7 mol%) when heated at a rate of 2°C/min. (O) before photoirradiation ( ) under photostationary state with ultraviolet irradiation (410 nm > A > 350 nm)...

Figure 8 Transmittance of poly(methacryloyl sulfamethazine monomer-co-iV -dimethyl acrylamide) as pH values of the solution at decrease, (a) 20mol% sulfamethazine, (b) 30mol% sulfa-...

Fig. 12.9. Infrared absorption spectra in D2O of polynucleotide solutions. Abscissa, frequency of absorption in cm. Ordinate, % transmittance on arbitrary scale. Conditions indicated in footnote to Table 12.2. (A) D O vs D2O to show compensation obtained. (B) Poly A + 2 poly U at 30 C. (C) Poly A + 2 poly U at about 60 C the arrow at 1632 cm" indicates the slight increase in absorption. (D) Tetra A + 2 poly U at 30°C. (E) Tetra A + 2 poly U at 60°C. The arrow indicates the large increase in absorption at 1625 cm". (Miles, 1960.)...

Figure 6. Temperature dependence of optical transmittance for poly(NIPAAm-co-Ru(bpy)3) solutions under the different conditions of reduced Ru(II) state (in Ce(lll) solution) and oxidized Ru(III) state (in Ce(IV) solution). (Reproduced from reference 25. Copyright 2002 American Chemical Society.)...

Fig. 1 Chromatograms of a standard solution of monoamine transmitters and their metabolites at (A) a poly(para-aminobenzoic acid) modified electrode and (B) a bare glassy carbon electrode. (1) Norepinephrine, (2) epinephrine, (3) dopamine, (4) 3,4-dihydroxyphenol acetic acid, (5) serotonin, (6) 5-hydroxyindole acetic acid, and (7) homovanillic acid. Source From Study on the effect of electromagnetic impulse on neurotransmitter metabolism in nerve cells by high performance liquid chromatography-electrochemical detection coupled with microdialysis, in Anal. Biochem. ...

Poly(ethylene terephthalate) is used to produce fibers or is processed as a thermoplastic material by injectionmolding or blow-molding. Sorption of pyrrole in films of this polymer followed by immersion of the film in an aqueous FeCls solution produced blends of polypyrrole and poly(ethylene tere late). The 30 /zm thick film obtained presented high optical transmittance at 633 nm and a conductivity in the range of 0.03-0.1 S cm [65]. Authors suggest that polypyrrole is distributed uniformly in the free volume of the poly(ethylene tereftalate) host, forming a conducting network at low concentrations (5%). 

Figure 7.9 Oscillating profiles of optical transmittance for poly(NIPAAm-co-Ru(bpy)j +)(Ru(bpy)5 + =5 wt%) solution at constant temperatures.

Figure 7.14 Chemical structure of poly(NIPAAm-co-Ru(bpy)j +-co-AMPS-co-MAPTAC) (a) and the oscillating profiles of the optical transmittance for the polymer solution at 12 °C when only MA (0.7 M fine dotted line, 0.5 M rough dotted line, 0.3 M solid line) is added to the solution (b).

Figure 1. Temperature-dependent transmittance changes of poly(DMAEMA) aqueous solutions. Conc.(wt%) A. 1.0 B. 2.5 C. 5.0 D. 10.0.

It would be of interest to add some functionalities such as properties in response to changes in pH, temperature, electrical potential and so on as well as hydrophilic properties to PTFE surfaces by the combined technique just described. Poly(AT-isopropylaoylamide) (PNIPA ) is a well-known thermo-responsive polymer whose hydrogel undergoes a volume change around 31 C in an aqueous solution. And further, poly 2-(dimethylamino)ethyl methacrylate (PDMA) in a pH 10 buffer solution exhibits a drastic decrease in the transmittance around 28 °C, which is considered to come from a phase transition of PDMA chains (ii). Therefore, we have tried to prepare JV -isopropylacrylamide (NIPAAm) or 2-(dimethylamino)ethyl... 

Figure 5. Change in Transmittance of Poly(siloxyethylene glycol) Aqueous Solution (1.5 wt. %) in Phosphate Buffer (pH = 7.0,1 = 0.05) (a) PSEG(l/n) (b) PSEG(2/n) (c) PVSE(l/7) (Number in Parentheses Denotes m / n in the Polymers)...

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