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1.
C. Z. Chuai S. Li K. Almdal J. Alstrup J. Lyngaae‐Jrgensen 《Journal of Polymer Science.Polymer Physics》2004,42(5):898-913
The compatibilization effect of polystyrene (PS)‐poly(dimethylsiloxane) (PDMS) diblock copolymer (PS‐b‐PDMS) and the effect of rheological properties of PS and PDMS on phase structure of PS/PDMS blends were investigated using a selective extraction technique and scanning electron microscopy (SEM). The dual‐phase continuity of PS/PDMS blends takes place in a wide composition range. The formation and the onset of a cocontinuous phase structure largely depend on blend composition, viscosity ratio of the constituent components, and addition of diblock copolymers. The width of the concentration region of the cocontinuous structure is narrowed with increasing the viscosity ratio of the blends and in the presence of the small amount diblock copolymers. Quiescent annealing shifts the onset values of continuity. The experimental results are compared with the volume fraction of phase inversion calculated with various theoretical models, but none of the models can account quantitatively for the observed data. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 898–913, 2004 相似文献
2.
Yuri M. Boiko Anders Bach Jørgen Lyngaae-Jørgensen 《Journal of Polymer Science.Polymer Physics》2004,42(10):1861-1867
Films of amorphous polystyrene (PS) with a weight-average molecular weight (Mw) of 225 × 103 g/mol were bonded in a T-peel test geometry, and the fracture energy (G) of a PS/PS interface was measured at the ambient temperature as a function of the healing time (th) and healing temperature (Th). G was found to develop with (th)1/2 at Th = Tg-bulk − 33 °C (where Tg-bulk is the glass-transition temperature of the bulk sample), and log G was found to develop with 1/Th at Tg-bulk − 43 °C ≤ Th ≤ Tg-bulk − 23 °C. The smallest measured value of G = 1.4 J/m2 was at least one order of magnitude larger than the work of adhesion required to reversibly separate the PS surfaces. These three observations indicated that the development of G at the PS/PS interface in the temperature range investigated (<Tg-bulk) was controlled by the diffusion of chain segments feasible above the glass-transition temperature of the interfacial layer, in agreement with our previous findings for fracture stress development at several polymer/polymer interfaces well below Tg-bulk. Close values of G = 8–9 J/m2 were measured for the symmetric interfaces of polydisperse PS [Mw = 225 × 103, weight-average molecular weight/number-average molecular weight (Mw/Mn) = 3] and monodisperse PS (Mw = 200 × 103, Mw/Mn = 1.04) after healing at Th = Tg-bulk − 33 °C for 24 h. This implies that the self-bonding of high-molecular-weight PS at such relatively low temperatures is not governed by polydispersity. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1861–1867, 2004 相似文献
3.
Nis Halland Tore Hansen Karl Anker Jrgensen 《Angewandte Chemie (International ed. in English)》2003,42(40):4837-4837
4.
5.
Leif Kjr Jrgensen 《Journal of Graph Theory》1989,13(1):75-85
A probabilistic result of Bollobás and Catlin concerning the largest integer p so that a subdivision of Kp is contained in a random graph is generalized to a result concerning the largest integer p so that a subdivision of Ap is contained in a random graph for some sequence A1, A2,… of graphs such that Ai+1 contains a subdivision of Ai. A similar result is proved for subdivisions with odd paths or cycles. The result is applied to disprove a conjecture of Chartrand, Geller, and Hedetniemi. The maximum number of edges in a graph without a subdivision of Kp, p = 4, 5, with odd paths or cycles is determined. 相似文献
6.
The reaction of metallic aluminium surfaces, aluminium oxides, hydrated oxides and sulphate with gaseous anhydrous hydrogen fluoride was studied at 470°C and pressures between 10 and 100 torr. The complementary analytical techniques of X-ray induced photoelectron spectra, X-ray and electron diffraction, and electron microscopy were used for identifying the (frequently unexpected) products. 相似文献
7.
Christian K. Jørgensen 《Chemical physics letters》1982,89(6):455-458
Recent relativistic calculations on the uranyl ion suggest that the low wave numbers of the first electron transfer bands are due to a bonding 5f-like orbital containing the two loosest bound electrons. Comparison with UF6 makes it more likely that if indeed σu (and not πu) is the highest occupied MO, it is rather due to “pushing from below” by U 6p (like N 2s in N2). 相似文献
8.
Using instrumental neutron activation analysis, the variations in the serum levels of Br, Cs, Na, Rb, Se, and Zn were investigated
in 18 persons in the normal state. By determining the element levels in relation to changes is the serum water content, information
about the binding to the serum protein was obtained. The influence of physiological factors on the serum element levels was
investigated. Changes in the concentrations due to variations in the protein/water ratio and in the zinc level as a result
of different posture were observed. When standardized sampling procedures were used, the variations in the serum element concentrations
during one hour and from day were found to be less than 10%. 相似文献
9.
Whereas uranyl compounds at most show electron transfer satellites at 3 eV higher I in the U4f region, mixed oxides containing uranium(V) show a characteristic satellite at 7.9 eV higher I. Uranium-cerium blue and certain U(IV) compounds are also discussed. 相似文献
10.
The chemical shift of core shell ionization energies in various perxenates relative to gaseous xenon is strongly compensated by interatomic relaxation. This effect is even more clear-cut on the Auger signals moving in the opposite direction of a (Hartree + Madelung) potential model. 相似文献