Effect of Solvent Quality on the Behaviour of Highly Charged Polyelectrolytes W. Essafi, F. Lafuma, C. Williams To cite this version: W. Essafi, F. Lafuma, C. Williams. Effect of Solvent Quality on the Behaviour of Highly Charged Poly- electrolytes. Journal de Physique II, EDP Sciences, 1995, 5 (9), pp.1269-1275. 10.1051/jp2:1995182. jpa-00248233 HAL Id: jpa-00248233 https://hal.archives-ouvertes.fr/jpa-00248233 Submitted on 1 Jan 1995 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. (1995) Phys. J. II France 1269-1275 5 SEPTEMBER1995, 1269 PAGE Classification Physics Abstracts 61.25Hq 70-y 36 20Fz 82 Communication Short Quality Highly Charged Solvent Elllect of the Behaviour of on Polyelectrolytes W. Essafi (~), Williams F. Lafuma and C. E. (~) (~ (*), Orsay, Paris-Sud, Universit6 LURE de (~) 91405 France Physicochinue ESPCI, Laboratoire de (**), Polymbres Vauquelin, des lo, (~) rue Paris, 75231 France (Received 1995) accepted July 1995, May received final 1995, form 16 in June 30 24 angles diffusion Rksumk. Une de de 6tude de RX 6nfission fluorescence petits et par so- aux (squelette hydrophobe) polystyrAne 2-acrylamido- sulfonate sodium lutions de de de et aqueuses (squelette hydrophile) 2-m6thyl-propane qual- l'importance sulfonate de sodium de la montr6 a charg6s, it6 solvant La de du la de 0,35 solutions fraction monomAres structure entre sur ces Manmng-Oosawa sup6rieure de de les Le I, seuil condensation et contre-ions. est pour au poly61ectrolyte hydrophile th60riques qualitativement propos6s, les modAles contrairement suit poly61ectrolyte hydrophobe pr6dictions le Atre confronts dont comportement peut au aux ne th60riques highly charged poly- experimentally Abstract. We show that the solutions of properties hy- depend electrolytes Polystyrene, with quality the backbone Sulfonated for the solvent on sulfonate), Poly(acrylamide-cc-sodiun~-2-acrylamido-2-methylpropane drophobic backbone, and hydrophilic investigated backbone, by SAXS with been in have fluorescence emission and a charge Manning-Oosawa of fraction between and above the I, 0.35 onset counterion range con- hydrophilic polyelectrolyte prediction whereas The follows the of the models densation. current polystyrene existing behaviour sulfonate be with model the of reconciled cannot any Introduction 1. Polyelectrolytes polymer suitable containing ionizable Once dissolved chains in groups. are a polar charges of pairs sign solvent such the dissociate. The electrostatic water, ions are one as charged whole the oppositely chain, localized whereas scattered the the counterions in on are prohibitively charged high lead coulombic highly chains, will solution. For this dissociation to CNRS-CEA-MEN (" Universit6 Curie CNRS (**) P. M. and et @ Physique Les Editions de 1995 PHYSIQUE JOURNAL DE II N°9 1270 evolves stable characterised repulsion charges. between chain Such the system to state more a approach by repulsive by condensation. This monitored the is weaker counterion interactions ib/b Manning-Oosawa11, theory charge relies reduced which based the parameter 2j on a on charges along polyion charge between the chain and the spacing b linear where the is 16, average exactly the coulombic Bjerrum length where thermal distance the the is compensates energy e~/£kT of charge, the the dielectric the where electron is interaction I-e- constant 16 £ e " the absolute solvent, k Boltzmann and T the temperature. constant ib/b ib/b assumed I, free the solution. When I, When all in it is counterions > < are charge polyion sufficient renormalize the reduced that will "condense" the counterions to to on I/(ib/b) charged of of unity; thus fraction the in the I parameter to monomers, case a by completely condensation of counterions, monovalent neutralised the the counterions is on the chain. 7121. synthetic polyelectrolytes, based In For water, temperature at most 16 room on " 1 polyvinylic backbone, condition of the of the order and thus the is size 2.5 a monomer ib/b larger charge for hold for than about all condensation will 0.35. counterion I contents > f condensed the will with regime, In this fraction of counterions increase reach constant to a Consequently polyelectrolytes, density order of for these the charge effective the 0.35. on equivalent governed and all characteristic features that electrostatic thus interactions are are Among them, solution, by of the should of the electrostatics chain the the not structure vary. angle by properties. evidenced small scattering its as entangled regime, isotropic semi-dilute the chains and form network. the In transient are an by scaling assembly (, picture blobs In the the solution described dense of of is size [3-5] a length length, Debye correlation the the which of screening order the electrostatic same is as (Kj 41rce~/£kT counterions). length 41rcib Kp~ where the of At free is concentration c = = polyelectrolyte (, forces the scales smaller than electrostatic dominant and rodlike has are a conformation larger similar that dilute solution For scales than the (, interactions in to are screened and each chain walk. random is out a reciprocal peak by isotropic model This characterised broad is in the in scatter- space, a (~~ profile ing depends polymer whose position scales thus and with concentration on cp as large dependence This by has been verified for of domain of concentration c)~~. means a light, particularly fully charged polystyrene scattering sulfonate X-ray for [6-8] and neutrons If I). = if I), charged fraction lowered If the of polymer concentration, is at constant < monomers if 0.35), polymer but of predicted still the above condensation position that the it is > onset unchanged scattering peak should of free of the the number since counterions remains remain Scattering provide experiments should therefore of sensitive the model. constant. test a poly(styrene- prediction The of this the that this verified of aim show is in to not paper is case sulfonate) (PSS) peak f linearly position found the almost with where co-styrene is to vary poly(acrylamide- f the behaviour will be in 0.3 contrasted that of I. This to < < range (AMAMPS), sulfonate) co-sodium-2-acrylamido-2-methylpropane position peak where the is The conditions. the results be discussed in quality of solvent will in constant since terms same hydrophobic PSS has hydrophilic opposed backbone AMAMPS the backbone. to very a as Experimental Section 2. polymers study of used this Figure chemical the shown A The random in in structure I. are bj (PSS) prepared of and sulfonate sulfonation copolymer of Na styrene post styrene was [9,10]. procedure (Mw Makowski polydispersity 2) based the and 250000 polystyrene on a = = (the charged) solubility of limit and (fully in between 0.3 density varied charge I The was N°9 EFFECT QUALITY OF SOLVENT POLYELECTROLYTES ON 1271 Na ~~2~j~~2~Y f"x/x+y PssNa / / ' ' ~ f=x/x+y H-CH2t( H-CH2)~ SAMPS ~O / NH-C(CH3)2-CH2-S03Na f=x/x+y AMAMPS (fH-CH2H(fH-CH2)~ f#O f=O NH2 NH-C(CH3)2-CH2-S03Na Fig. polyelectrolytes Chemical study this of the used in I. structure Poly(acrylamide-co-sodium-2-acrylamido- water), explored study. before this range never a sulfonate) 2-methylpropane synthesized copolymerisation acrylamide methyl by of with was ill] according procedure sulfonic slightly modified acid standard which to to propane was a polyelectrolytes. highly charged obtain (SAXS). Angle Scattering by measured The of the has the Small been solution X structure ray performed SAXS synchrotron D22, line L.U.R.E DCI beam the using measurements at were on ii crystals parallel radiation The beam monochromated with Ge intense II to two source. was l.371 mm~. wavelength ray-photons and ~ collimated The scattered X 0.5 0.5 to x were a = position resolution detected with with The dimentional sensitive detector of 217 ~m. one a a l~l 9/~, explored half (q included between and where 41r 0.005 0.22 sin is range q q one was = l~~ angle). scattering dilute the "Salt-free" solutions of monomol semi concentration 0.32 at a dissolving polyelectrolyte prepared by dry deionized the minutes, C for in 50 30 water at ° were days then before investigation. let for the Great temperature two to rest at care was room 10~~ l~~). ire keep the taken the residual salt value For minimum mol concentration at to a kapton samples SAXS enclosed cell the thick with 50 in 1.2 measurements, ~lm were a mm resulting the intensity intensity, windows. The corrected for beam the scattered incident was background scattering. sample and thickness and the transmission l~~ 10~~ of solutions of Fluorescence monomol dilute of 2.72 in measurements pyrene x performed. dissolved first ethanol PSS AMAMPS The in in at water pyrene a was were or 10~4 l~~ polyelectrolyte added solutions then the and of concentration mol 6 to to up x was 10~? l~~. experiments fluorescence conducted final 25 mol of The at 6 concentration were x a wavelength and the The 334 500-SPF excitation C with AMINCO spectrometer. ° was nm an PHYSIQUE N°9 II JOURNAL DE 1272 of for The emission. intensities for excitation and emission band 0.5 5 at set pass nm nm were respectively, used calculate peaks first and third 373 and 384 the emission to at nm were nm averaged Ii/13 solubilisation all polarity local characterizes the the which ratio pyrene over sites.