synopsisA simple theory for the relaxation of concentration fluctuations in polyelectrolyte solutions is presented, and particular results for the high-salt and no-salt limiting cases are discussed.Autocorrelation functions for the fluctuating intensity of scattered light from dilute aqueous solutions of poly(t1ysine HBr) (PLL-HBr) with and without added salt have been observed over a wide range of pH. The observed autocorrelation functions are in general very satisfactorily represented by single exponentials except at high pH (>10.5), where considerable aggregation is manifested. Solutions of PLL HBr without added salt exhibit extraordinary behavior, evident at low pH, involving a species with a very slowly decaying autocorrelation function. Though this species is readily annealed to a more ordinary individual freemolecule form by cycling the pH to 9.5 or higher and back, the resulting molecules are found to require unusually long times to reach internal configuration equilibrium under low pH conditions. Solutions of PLGHBr in 0.2M NaBr and 0.1M NaCl are apparently free of simiiar extraordinary effects and show the normal isothermal helii-coil transition accompanied by a 15-30% rise in the diffusion coefficient to a maximum at pH 10.5, which is interpreted in terms of a change in molecular dimension of an interrupted helix.The predicted Kz dependence of the reciprocal relaxation time and enhancement of the apparent diffusion coefficient of the polyelectrolyte in the absence of salt is confirmed. LEE AND SCHURR -8 -7 -. 'c) 6 -4 2 Y 5 -9 ~4 -* 3 -2 -Poly -Llysine conc. PH hydrobromide : 8 . 7 m g / m l : 4.1 T in water Fig. 4. Reciprocal relaxation time l / r vs. dnz (8/2) for 8.7 mg/ml PLGHBr in water without the preaence of added salt.B exp $ -t / r .)$z + C was necessitated. This finding may suggest that internal modes of some kind are involved, but we have as yet no detailed explanation to offer. Further studies are, however, in progress. Recent experiments show that the solution returns to the extraordinary condition after dialyzing out the salt. Science Foundation.

Abstract. Poor filling occurs during the injection molding process of micro-or nano-scale patterns mainly because the hot polymer melt rapidly cools and its skin quickly solidifies upon contact with the mold surface. In this study, it is proposed to use Polyethylene terephthalate (PET) film coated with patterned polyurethane acrylate (PUA) as an effective thermal barrier. It can significantly hinder heat transfer into the mold during the molding process and thus may keep the melt viscosity low for longer duration. As a result, the replication would be improved not only during the filling phase but also during the packing phase. In order to verify the validity of the use of polymeric stamper, the melt-film interface temperature was evaluated by numerical simulation. Experimental results indicated that patterns possessing widths within the range of one to tens of micrometers and a height of approximately 10 !m were successfully filled and demolded.