Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 23 (1990), S. 1370-1374 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 28 (1995), S. 1541-1546 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1435-1528
    Keywords: Key words Rheology ; liquid crystalline polymer ; hydroxypropylcellulose ; band texture ; polydomain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract The viscosity of a main-chain liquid crystalline polymer (anisotropic aqueous solution of hydroxypropylcellulose) is measured in the case where the liquid crystalline polymer presents a band texture and is compared to the case of a polydomain texture.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Rheologica acta 29 (1990), S. 366-368 
    ISSN: 1435-1528
    Keywords: Thermotropicpolymers ; smecticphase ; shearflow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract The rheology of a smectic main-chain polymer shows that the activation energy is high (275 kJ mol−1) and that the viscosity is more than two orders of magnitude higher than in the isotropic phase. The recoverable strain in the smectic phase is largely due to the reformation of the smectic layers after cessation of shear.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 22 (1981), S. 107-118 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Résumé La N-méthylmorpholine N-oxyde (MMNO) a une température de fusion de 184.2°, une enthalpie de fusion de 160.5 J/g et une chaleur de décomposition de 1340 J/g. Son hydratation a été étudiée par analyse calorimétrique différentielle et par gravimétrie. A l'air et à la température ambiante, la quantité totale d'eau qui a diffusé dans la MMNO correspond à quatre molécules d'eau par molécule de MMNO. Plusieurs complexes MMNO-H2O cristallins ont été mis en évidence par analyse calorimétrique differentielle: un complexe MMNO-2.5 H2O (T f =40.5°,ΔH f =143.4 J/g), un complexe MMNO-1 H2O (T f = 75.6°,ΔH f =160.5 J/g) et un complexe dont la quantité d'eau n'a pas été déterminée (T f =102°,ΔH f =95 J/g).
    Abstract: Zusammenfassung Das N-Methylmorpholin N-Oxid (MMNO) hat eine Schmelztemperatur von 184.2°, eine Schmelzenthalpie von 160.5 J/g und eine Zersetzungswärme von 1340 J/g. Seine Hydratisierung wurde durch differentialkalorimetrische Analyse und durch Thermogravimetrie untersucht. In Luft und bei Raumtemperatur entspricht die gesamte, in das MMNO diffundierte Wassermenge 4 Wassermoleküle pro Molekül MMNO. Durch die differentialkalorimetrische Analyse wurden verschiedene kristalline MMNO-H2O-Komplexe nachgewiesen: ein Komplex MMNO-2.5 H2O (T f =40.5°,ΔH f =143.4 J/g), ein Komplex MMNO-1 H2O (T f =75.6°,ΔH f =160.5 J/g) und ein Komplex, dessen Wassergehalt nicht bestimmt wurde (T f =102°,ΔH f =95 J/g).
    Notes: Abstract N-methylmorpholine N-oxide (MMNO) has a melting temperature of 184.2°, an enthalpy of fusion of 160.5 J/g and a heat of decomposition of 1340 J/g. Its hydration has been investigated by differential scanning calorimetry (DSC) and by gravimetry. In air and at room temperature, the total amount of water diffusing into MMNO corresponds to four molecules of H2O per molecule of MMNO. Several MMNO-H2O crystalline complexes have been studied by DSC: an MMNO-2.5 H2O complex (T f =40.5°,ΔH f =143.4 J/g), an MMNO-1 H2O complex (T f =75.6°,ΔH f =160.5 J/g) and a complex with an unknown amount of water (T f =102°,ΔH f =95 J/g).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 29 (1984), S. 405-414 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Eine Beschreibung von Phasenübergängen, registriert durch DSC, wird gegeben. Eine neue ZahlN wird eingeführt und alsN=h′/h definiert, wobeih die Höhe des Übergangspeaks für die Probenmassem und die Aufheizgeschwindigkeit† p undh′ die Höhe des gleichen Peaks für die Masse2m oder die Aufheizgeschwindigkeit2† p sind.N ist im Falle isothermer und nichtisothermer Übergänge erster Ordnung und eines Phasenübergangs zweiter Ordnung theoretisch ableitbar. Die Äquivalenz von Masse und Aufheizgeschwindigkeit wurde überprüft. Ein Beispiel für eine mögliche Anwendung vonN wird angegeben.
    Abstract: Резюме Приведено описание ф азовых переходов, установленных метод ом ДСК. Новый параметрN определяет ся выражениемN=h′/h, гдеh-высота пика переход а для образца с массойm и скорости н агрева †n, аh′-высота т ого же самого образца с масс ой 2m и скорости нагрева 2†n. В еличинаN теоретичес ки выведена в случае изо термических и неизотермических фа зовых переходов перв ого порядка и фазового перехода вт орого порядка. Доказана экв ивалентность массы и скорости нагрева. Приведен при мер возможного использования парам етраN.
    Notes: Abstract A description of phase transitions as recorded by differential scanning calorimetry (DSC) is given. A new numberN is defined asN=h′/h, whereh is the height of a transition peak for a mass of samplem and a heating rate †p andh′ is the height of the same peak for a mass2m or a heating rate2† p .N is theoretically derived in the case of isothermal and nonisothermal first order phase transitions and of a second order phase transition. The equivalence of mass and heating rate is proved. An example of the possible use ofN is given.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 29 (1984), S. 415-421 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Für verschiedene Materialien wurden die Übergänge Flüssigkeitskristall → Flüssigkeitskristall und Flüssigkeitskristall → isotrope Flüssigkeit untersucht, wobei eine ZahlN eingeführt wurde, die als das Verhältnish′/h der Höhen der Übergangspeaks bei den Aufheizgeschwindigkeiten† p bzw.2† p definiert ist. Es wurde festgestellt, daßN nahe 2 ist, was zeigt, daß in Übereinstimmung mit den diese Übergänge beschreibenden aktuellen Theorien die Wärmekapazität in der Nähe der Übergangstemperatur ansteigt.
    Abstract: Резюме Изучены для некоторы х веществ переходы ти па жидкий кристалл-жидк ий кристалл и жидкий кристалл-изо тропная жидкость, исп ользуя параметрN, определяе мый отношениемh′/h, гдеh иh′-высота пик ов перехода при скоро стях нагрева, соответстве нно, †n и 2†n. Найденный пара метрN близок к значен ию 2, что свидетельствует об у величении теплоемкости около т емпературы перехода. Это явление согласуется с теория ми, принятыми для описания таких пе реходов.
    Notes: Abstract Liquid crystal → liquid crystal and liquid crystal → isotropic liquid transitions of several materials are studied using a numberN, whereN is defined as the ratioh′/h, h andh′ being the heights of the transition peaks at heating rates† p and2† p respectively.N is found close to two, which shows that a heat capacity increase occurs near the transition temperature, in agreement with the current theories describing these transitions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 30 (1985), S. 61-64 
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Eine neue Methode zur Unterscheidung von Umwandlungen erster und zweiter Art in flüssigen Kristallen wird vorgeschlagen, die auf Anwendung des VerhältnissesN=h/h0 basiert, wobeih 0 die Höhe des durch DSC bei einer AufheizgeschwindigkeitT p und für die Massem registrierten Umwandlungspeaks undh die Höhe des entsprechenden Peaks bei Verdoppelung der Aufheizgeschwindigkeit oder der Masse bedeuten. Auf die Anwendung dieses neuen Konzepts auf Phasenübergänge in Octylcyanobiphenyl (8CB) wird eingegangen.
    Abstract: Резюме Предложен новый мето д дифференциации переходов первого и в торого порядков в жидких кристалличе ских системах. Метод о снован на использовании соо тношенияN=h/h 0, гдеh 0-высота темпер атурного пика, измере нного методом ДСК при скоро сти нагреваT p и с массойm, аh-высота соответствующего пи ка при двойной скорос ти нагрева и массе. Показано прим енение новой концепц ии к фазовым переходам в октилциа но-бифениле.
    Notes: Abstract A new method for differentiating first- and second-order transition in liquid crystalline systems is proposed. It is based on the use of the ratioN=h/h 0, whereh 0 is the height of the transition peak recorded by DSC at a heating rateT p with a massm, andh is the height of the corresponding peak when the heating rate or the mass is doubled. The application of this new concept to phase transitions in octylcyanobiphenyl (8CB) is mentioned.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 211-219 
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Loss and storage moduli were measured by eccentric disk rheometry for isotropic and anisotropic hydroxypropylcellulose solutions. Two rheological regimes exist for the anisotropic solution, one at low deformation ratios (less than 80%) and one at high deformation ratios (more than 100%). For the high-deformation regime, the comparison between dynamic and steady-state parameters is consistent with what is known from the literature. The data on the low-deformation regime are new and are characterized by loss and storage moduli two orders of magnitude larger than those in the high-deformation regime. This difference is not due to a cholesteric to nematic transition nor to an elastic to viscoelastic transition (yield stress). It is postulated that a network of defects stabilized by chain molecules could give such a low deformation behavior.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 30 (1992), S. 865-869 
    ISSN: 0887-6266
    Keywords: light scattering, small-angle cross-polarized, from birefringent sphere (theory) ; birefringent sphere, theory of light scattering from ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Rayleigh-Gans-Debye approximation is used to investigate the small-angle, cross-polarized light scattering by a sphere of radius a, birefringence Δμ and relative index μ. If θmax is the polar scattering angle of the intensity maxima, the quantity Ûmax = 4πa/λ × sin (θmax/2) behaves in two different ways according to the signs of Δμ and μ - 1. When Δμ 〉 0, μ 〉 1 or Δμ 〈 0, μ 〈 1, then Ûmax varies from 2.8 to 4.1 as Δμ increases from zero. If Δμ 〈 0, μ 〉 1 or Δμ 〉 0, μ 〈 1, then Ûmax goes from 2.8 to about 6, thereafter decreasing to 4.1. Another interesting result is that the value of Ûmax for a highly briefringent sphere is 4.1 only for large diameters. It decreases to 4.0 when the diameter decreases.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...