Über Symplexe von Cellulosederivaten. 8. Mitt. Untersuchungen zur Wasserquellung unterschiedlicher Symplexfällungen

Philipp, B.; Hong, Li-Li; Linow, K.‐J.; Dawydoff, W.; Arnold, Klaus

doi:10.1002/actp.1980.010311007

Cited by 17 publications

(3 citation statements)

References 3 publications

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“…Further details on the synthesis and characterization of these polymers have been published by us [10]. Further details on the synthesis and characterization of these polymers have been published by us [10].…”

Section: Methodsmentioning

confidence: 99%

“…While in earlier work the realizability of 1:1 PEC's ("stoichiometric polysalts") has been emphasized [3], recent publications [4,5] have given more attention to the deviations from this 1:1 stoichiometry, which were stressed for the first time in the work of Tsuchida [6]. In summarizing our own work in the intermediate range between the area of the macroscopic homogeneous system with quasi-soluble PEC aggregates [9] and the area of macroscopic PEC precipitation [10], we tried to give an interpretation of the formation of these non-stoichiometric PEC [11]. According to our own results [8], deviations from a 1:1 stoichiometry can be due to structural features of the PEC components, as well as to the procedure of PEC formation.…”

Section: Introductionmentioning

confidence: 99%

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Amphoteric character of polyelectrolyte complex particles as revealed by isotachophoresis and viscometry

Kötz¹,

Philipp²,

Sigitov³

et al. 1988

Colloid & Polymer Sci

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Isotachophoresis and viscometric measurements were performed on aqueous dispersions of non-stoichiometric polyelectrolyte complexes in order to elucidate the surface charge situation of the complex particles in dependence on component charge density, ratio of cationic to anionic groups in the complex, and pH and ionic strengths of the ambient medium. Components for complex formation were acryl-based anionic and cationic polyelectrolytes of the pendent type. From our results, an amphoteric character of the polyelectrolyte complex particles can be concluded, with an isoelectric point characterized by zero mobility and a minimum in reduced viscosity r/spec/c of the particle dispersion, and with the sign of net surface charge depending on ambient pH and component charge density. The influence of ionic strength on the rlspJc vs pH plots can be interpreted by assuming a competition between salting-out and electrostatic shielding effects. No correlation could be established between the overall molar ratio of cationic to anionic groups and the isoelectric point of the complex particles, which obviously indicates a different composition of "surface" and "bulk" of the polyelectrolyte complex particles.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Amphoteric character of polyelectrolyte complex particles as revealed by isotachophoresis and viscometry

Kötz¹,

Philipp²,

Sigitov³

et al. 1988

Colloid & Polymer Sci

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“…Letztere finden in Form ebenflachiger Membranen [4, 51 oder in Form von Symplex-Mikrokapseln [6, 71 zunehmend Interesse als Trennmedien.In friiheren SEM-[8, [lo] hatten wir auf die breite Variabilitat der Morphologie solcher Symplexfiillungen hingewiesen und gezeigt, daB neben fibrillaren Netzwerkstrukturen raumliche Domanenstrukturen in solchen Polgmergebilden auftreteii. In[lo] hatten wir erstmals den EM-Aufnahmen von Ultradunnschnitten einige Oberflachenabdrucke von Erstarrungsmorphologien von Symplexen gegenubergestellt und am Beispiel des Systems Quartolan(R)/ Cellulosesulfat darauf hingewiesen, daB die Gefrieratztechnik zur in-situ-Verfolgung des zeitlichen Verlaufs der Bildung solcher Koagulationsstrukturen besonders geeignet erscheint.Ausgehend von diesen damaligen orientierenden Untersuchungen sollen im folgenden Beitrag einige mittels Gefrieratztechiiik erlialtene Ergebnisse zu Struktul-und Bildungsweise solcher S~-niplexfaillungeii zusammengefaBt werden, wobei vertiefende Aussagen zur Strukturhildung im Grenzbereich zwischen Syniplexgel und den angrenzenden Losungen im Mittelpunkt stehen.l) 3.…”

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Morphologische Untersuchungen an Polymergelen und zum Sol‐Gel‐Übergang mittels Gefrieräzung. 4. Mitt.: Bildung von Symplexgelen durch Polyanion‐Polykation‐Wechselwirkung

Hartmann¹,

Philipp²,

Dautzenberg³

et al. 1987

Acta Polymerica

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Unter Anwendung der Gefrieratztechnik wurde die durch Wechselwirkung zwischen waBrigen Losungen anionischer und kationischer Polyelektrolyte erfolgende Bildung von Symplexgelen untersucht. Die groBe morphologische Vielfalt solcher Symplexgele zeigt sich in einem unterschiedlichen Aufbau der primar entstehenden Gelgrenzschicht zwischen den beiden Polymerlosungen, einem recht unterschiedlichen Dickenwachstum des Gelfilms und in unterschiedlichen morphologischen Strukturelementen (Partikel, Fihrillen, groBere abgerundete Domanen! in der Volumenphase des Gelfilms, der insgesamt einen asymmetrischen Aufbau zeigt. Mogliche Ursachen dieser morphologischen Vielfalt von Symplexgelen werden erortert, wobei vor allem der Unterscheidung zwischen ,,hart" fallenden und ,,weich" fiillenden Polyelektrolytsystemen Bedeutung zugemessen wird. Mopg!ioAoicuuecicue uccmdoeanu nomaepnax zeaeii u nepexoaa3 0~b -z e m . Coobtq. 4-e: 06paaosanue cu.nnneiccrmx zeaeii s peayaamame eaau.~odeiicmeu~ noauanuona c noauicamuono.u MeTOAOM TpaBJIeHElII 8aMOpaXCUBaHIfeM 113Y' leHO 06pa30BaHUe CHMnJIeKCHbIX I'eJIefi B pe3yJIbTaTe B3aHMO~efiCTBIIII BOAHbIX PaCTBOpOB aHIIOHHbIX 12 KaTIlOHHbIX IIOJII13JIeKTPOJIllTOB. BOJIbIuaII MOp@OJIOrH'leCKaII MHOF006pa3HOCTb TaKIIX CHMIIJIeKCHbIX reJIefi OKa3bIBaeTCR B pa3JIM'lHOM CTPOeHMM lTepBII'lH0 06pa3yroqeroc~i reJIeBHnHOr0 norpa-HH'lHOrO CJIOII Memay 06011~11 PaCTBOpaMEl IIOJIHMepOB, B AOBOJIbHO pa3JIHqHOM POCTe IIO TOJIq11He reneB11AHOfi IIJIeHKH, a TaKme B pa3JIWIHbIX MOp@OJIOrWieCKIIX 3JIeMeHTOB CTPYKTYPbI (YaCTEIqbI, @ E~~P P~J I J I~I , 6onee KpyIIIIIle OKpyrJIeHHbIe AOMeHbI) B 06'6eMHOfi @a3e reJieB11AHOfi IIJIeHKEI, B o 6 4 e~ IIMeiOqefi aCHMMeTpHYeCKOe CTpOeHFie. O6cymnam~ca B03MOXCHbIe IIpWiIlHbI TaKOfi MOp@OJIOI' WIeCKOfi MHOl' OO6pa3HOCTH CMMIIJIeKCHbIX PeJIefi, Ilp11WM IIOn'lepK11BaeTCII H~O~X O~X I M O C T~ pa3JIH'leHHH MeHE,Q' ,,HteCTKO" II , ,MHPKO'' OCamAaIoqEiMII CElCTeMaMII IIOJl113JIeK-TPOJIIITOB. Morphological investigations on polymer gels and on the sol-gel transition by means of freeze-etching method. 4th Comm.: Formation of symplex gels by the interaction of polyanions and polycationsEmploying the freeze-etching technique, the formation of symplex gels obtained by interaction between anionic and cationic polyelectrolytes in aqueous solution has been investigated. The large morphological variability of these symplex gels originates from a different structure of the primary gel-layer between the polymer solutions as well as from a different growth-rate of thickness of the gel film and from the variability of structural elements (particles, fibrils, larger polymer domains with smooth outer contour) in the volume phase of the gel-film, which generally shows an asymmetric structure. Possible causes of the morphological variability of symplex gels are considered, emphasizing the importance of discerning between "hard" and "soft" modes of precipitation in dependence on the polyelectrolyte system employed.

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Symplex‐Membranen aus Dreistoff‐Gemischen

et al. 1981

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Über Symplexe von Cellulosederivaten. 8. Mitt. Untersuchungen zur Wasserquellung unterschiedlicher Symplexfällungen

Cited by 17 publications

References 3 publications

Amphoteric character of polyelectrolyte complex particles as revealed by isotachophoresis and viscometry

Amphoteric character of polyelectrolyte complex particles as revealed by isotachophoresis and viscometry

Morphologische Untersuchungen an Polymergelen und zum Sol‐Gel‐Übergang mittels Gefrieräzung. 4. Mitt.: Bildung von Symplexgelen durch Polyanion‐Polykation‐Wechselwirkung

Symplex‐Membranen aus Dreistoff‐Gemischen

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