Small-angle neutron scattering (SANS) experiments on solutions of polystyrene (PSH) and its deuterated homologue (PSD) in deuterated toluene have been performed over a wide range of concentration.Several redundant measurements demonstrated that the high-concentration technique of extracting single-chain scattering functions is highly reliable. Radii of gyration and screening lengths were fitted to power laws and were found to be R N c-".lW and f N c-".'O. The resulta differ significantly from predictions by scaling theory, though the dependence of E on c is in good accord with that previously found by other researchers. These experiments were also analyzed by using recent theoretical results of Muthukumar and Edwards. Measurements at different concentrations yielded a reasonably consistent value of the excluded volume interaction parameter.

Wave length in microns. Fig. 2.-Infrared spectrum of product: curve A, liquid, 0.025 mm. cell; curve B, gas, sat. vapor, 10 cm. cell; curve C, gas, 60 mm. pressure, 10 cm. cell. and 3030 cm.-1 correspond to those reported for ordinary chloroform.6•6 Several very weak minima occurring at 991, 1097 and 1171 cm.-1 possibly result from combinations of the fundamentals.Since the minimum at 1218 cm.-1 appeared to persist even in low concentrations of ordinary chloroform, it was decided to use this minimum as a basis for the quantitative analysis of the product. The standard solutions of chloroform in benzene possessed a minimum at this point and obeyed the Beer-Lambert law, as observed in Fig. 3. Transmission of the product (dotted line) corresponded to 6.1 g. of ordinary chloroform in 100 ml. of product or to a 0.960 mole fraction of chloroform-d. The average deviation as estimated from the results of three determinations was 0.008 mole fraction units.Assuming equimolar volumes, the observed density increment of the product as compared to the calculated corresponds to a 0.952 mole fraction, in good agreement with the above analysis.

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Raman displacements, semiquantitative relative intensities, quantitative depolarization factors, and wave numbers and percent transmission for the infra-red bands in the region 400–5000 cm−1 have been obtained for CBr3D. Details about the measurement of the depolarization factors are given. Thermodynamic properties—heat content, free energy, heat capacity, and entropy—have been calculated from the spectroscopic and molecular structure data for eight temperatures from 298.16° to 1000°K.

Small-angle scattering measurements from protonated polystyrene (PSH) and mixtures of deuterated and protonated toluene (C7D8 and C7H8) are presented. The data are compared with the simple 'quasiisotropic' Vineyard model, corrected for third-and higher-order multiple scattering by Monte Carlo methods. This model agrees surprisingly well with all protonated samples over the total thickness range considered. The empirical Jacrot g factor in the expression I(Q) = K(1 -T)g(2)/4n works well over a more limited thickness range. The effective differential cross section can be calculated using Melkonian total cross sections, and this gives an absolute scattered intensity which is 9% lower than a calibration performed at Oak Ridge National Laboratory. Scattering from oversize samples must be back shielded. The model requires an anisotropic kernel to predict D/H toluene mixtures.