Search

Demand for direct chemical modification of functional material on a surface is increasing in various fields. A new approach for a functionalized surface is investigated by applying a conventional laser in order to generate chemical activation by photothermal energy. Poly(ethyleneimine) (PEI), with a high density of amino groups, is chemically grafted on poly(methyl methacrylate) (PMMA) by irradiation of a CO2 laser (10.6 μm). Laser parameters such as power, scan rate, and focal length are observed to play an important role in order to introduce effective photothermal energy for the chemical reaction between PEI and PMMA. By optimization of laser parameters, the amide compound is produced as a result of the reaction of amine from PEI and the ester of PMMA successfully. The PMMA surface modified with PEI is analyzed by XPS and TOF-SIMS to identify the functional groups. Furthermore, the surface is characterized in terms of wettability, adhesion force, and surface charge for various applications. Finally, reaction with dye and metal on the amine-terminated PMMA shows promising results in supplying a selective and reliable functional substrate.

The increasing demand and implementation of pharmaceutics poses severe risk to different aquatic species as detectable contaminant in almost every surface water worldwide. Diclofenac (DCF) as one of the most common used analgesics was investigated as contaminant to be removed by adsorption onto nanoporous poly(melamine-co-formaldehyde) (PMF) particles featuring a very high amount of nitrogen functionalities. To achieve a high specific surface area (up to 416 m

The human-made pollution of surface and ground waters is becoming an inevitable and persistently urgent problem for humankind and life in general, as these pollutants are also distributed by their natural circulation. For example, from mining activities and metallurgy, toxic heavy metals pollute the environment and present material risk for human health and the environment. Bioadsorbers are an intriguing way to efficiently capture and eliminate these hazards, as they are environmentally friendly, cheap, abundant, and efficient. In this study, we present brewers’ spent grain (BSG) as an efficient adsorber for toxic heavy metal ions, based on the examples of iron, manganese, cadmium, and nickel ions. We uncover the adsorption properties of two different BSGs and investigate thoroughly their chemical and physical properties as well as their efficiency as adsorbers for simulated and real surface waters. As a result, we found that the adsorption behavior of BSG types differs despite almost identical chemistry. Elemental mapping reveals that all components of BSG contribute to the adsorption. Further, both types are not only able to purify water to reach acceptable levels of cleanness, but also yield outstanding adsorption performance for iron ions of 0.2 mmol/g and for manganese, cadmium, and nickel ions of 0.1 mmol/g.

Catalytically active porous and hollow titania nanofibers encapsulating gold nanoparticles were fabricated using a combination of sol-gel chemistry and coaxial electrospinning technique. We report the fabrication of catalytically active porous and hollow titania nanofibers encapsulating gold nanoparticles (AuNPs) using a combination of sol-gel chemistry and coaxial electrospinning technique. The coaxial electrospinning involved the use of a mixture of poly(vinyl pyrrolidone) (PVP) and titania sol as the shell forming component, whereas a mixture of poly(4-vinyl pyridine) (P4VP) and pre-synthesized AuNPs constituted the core forming component. The core-shell nanofibers were calcined stepwise up to 600 °C which resulted in decomposition and removal of the organic constituents of the nanofibers. This led to the formation of porous and hollow titania nanofibers, where the catalytic AuNPs were embedded in the inner wall of the titania shell. The catalytic activity of the prepared Au@TiO2 porous nanofibers was investigated using a model reaction of catalytic reduction of 4-nitrophenol and Congo red dye in the presence of NaBH4. The Au@TiO2 porous and hollow nanofibers exhibited excellent catalytic activity and recyclability, and the morphology of the nanofibers remained intact after repeated usage. The presented approach could be a promising route for immobilizing various nanosized catalysts in hollow titania supports for the design of stable catalytic systems where the added photocatalytic activity of titania could further be of significance.

The modification of the biobased polymer chitosan is a broad and widely studied field. Herein, an insight into the hydrophobization of low-molecular-weight chitosan by substitution of amino functionalities with hexanoyl chloride is reported. Thereby, the influence of the pH of the reaction media was investigated. Further, methods for the determination of the degree of substitution based on 1H-NMR, FTIR, and potentiometric titration were compared and discussed regarding their accuracy and precision. 1H-NMR was the most accurate method, while FTIR and the potentiometric titration, though precise and reproducible, underlie the influence of complete protonation and solubility issues. Additionally, the impact of the pH variation during the synthesis on the properties of the samples was investigated by Cd2+ sorption experiments. The adjusted pH values during the synthesis and, therefore, the obtained degrees of substitution possessed a strong impact on the adsorption properties of the final material.

Polyethyleneimine (PEI) cryogels have been fabricated using poly(ethylene glycol) diglycidyl ether (DGE-PEG), 1,4-butanediol diglycidyl ether (DGE-1,4-BD), and glutaric aldehyde (GA) as cross-linking agents. The rate of PEI cross-linking changes in the order GA > DGE-1,4-BD > DGE-PEG. The established correlations between the modification degree, swelling, and static ion-exchange capacity revealed a tendency of diglycidyl ethers, especially DGE-1,4-BD, to graft as a side chain to PEI in alkaline media. Low reactivity of cross-linkers at temperatures below zero resulted in lower modification degree and higher sorption capacities of PEI cryogels in comparison with PEI cross-linked at room temperature. Due to the difference in mechanisms of sorption of metal cations and anions, PEI cryogels cross-linked with DGE-1,4-BD and DGE-PEG were the most efficient for sorption of Hg(II) as [HgCl4]2− complex and Cu(II) ions, respectively. The morphology of PEI cryogels depends on the type of the cross-linking agent, cross-linker/PEI molar ratio, and concentration of PEI solution; the pore volume of cryogels obtained under the same conditions decreased in the order GA > DGE-1,4-BD > DGE-PEG.

The immobilisation of silica nanoparticles on the surface of a flowing polymer melt is studied during injection moulding. We use silica nanoparticles of identical size of about 200 nm, but with different surface functionalities: plain unmodified particles with silanole groups as well as amino- and hydrocarbon modified particles. The particles were brought in contact with a polycarbonate melt at a temperature of 300 °C. In our investigation, we show that particles with polar surfaces are more embedded than those with non-polar surfaces. Immobilised polar particles exhibited also a higher adhesion, tested with an adhesive tape, whereas the non-polar particles can be easily removed by peeling off the adhesive tape. This paper reveals that surface properties have a larger influence on embedding of nanoparticles than thermal conditions due to cooling of the melt.

In this work, the flocculation efficiency of reacetylated chitosans were compared with those of commercially available chitosans. The flocculation properties were investigated in dispersion of clay by means of turbidity measurements, colloid titration and measurements of the floc size. Reacetylated chitosan dissolves in deionized water without any additives and exhibits good flocculation properties like a wider flocculation window but a higher amount of polymer. For commercial chitosan lower amounts of polymer were required for the flocculation of clay dispersion. Flocculation with commercial chitosan is possible even in basic range.

Catalytically active porous and hollow titania nanofibers encapsulating gold nanoparticles were fabricated using a combination of sol-gel chemistry and coaxial electrospinning technique. We report the fabrication of catalytically active porous and hollow titania nanofibers encapsulating gold nanoparticles (AuNPs) using a combination of sol-gel chemistry and coaxial electrospinning technique. The coaxial electrospinning involved the use of a mixture of poly(vinyl pyrrolidone) (PVP) and titania sol as the shell forming component, whereas a mixture of poly(4-vinyl pyridine) (P4VP) and pre-synthesized AuNPs constituted the core forming component. The core-shell nanofibers were calcined stepwise up to 600 °C which resulted in decomposition and removal of the organic constituents of the nanofibers. This led to the formation of porous and hollow titania nanofibers, where the catalytic AuNPs were embedded in the inner wall of the titania shell. The catalytic activity of the prepared Au@TiO

Copper(II) as a heavy metal ion is posing risk to aquatic ecosystems including algae, fish, mollusks, and bacteria, negatively affecting human life because of bioaccumulation and non-biodegradability. In this study, two thermoresponsive PNIPAM-b-PAA block copolymers with different characteristics in terms of molecular weight and PAA composition were investigated to remove copper ions from simulated water. We chose to utilize those block copolymers in CuSO4 adsorption experiments in order to comprehend how the combination of the thermoresponsive PNIPAM block and the binding ability that PAA block offers, affects the adsorption of Cu2+ and SO42− and provides eventually their removal from aqueous solutions. The adsorption protocol includes simple mixing of the copolymer and CuSO4 aqueous solutions under stirring. Dynamic and electrophoretic light scattering, pH, UV–vis, turbidity and ICP-OES measurements were conducted to verify the PNIPAM-b-PAA ability as smart adsorbents. The results showed that the PNIPAM-b-PAA_50−50 sample offers the possibility of Cu2+ and SO42- adsorption of greater percentage especially when temperature increases to 60 °C. Therefore, PNIPAM-b-PAA block copolymers comprise efficient and smart Cu2+ and SO42- adsorbents.

Chitosan (flakes with a degree of deacetylation of 90%) was used as adsorbent for heavy metal ions in solution (copper, iron, nickel). The adsorption capacities were determined in dependence on the adsorption time and the initial metal salt concentration. With increasing adsorption time as well as the initial metal salt concentration the adsorption capacities increased. Highest adsorption capacity was achieved for copper(II)ions with 110 mg/L. Iron(II)- and nickel(II)ions adsorbed with an adsorption capacity of 80 mg/L. The surface of chitosan flakes were investigated before and after the adsorption process by SEM and SEM-EDX, respectively. The formation of crystal-like structures was observed by SEM analysis for the investigation of copper(II)sulfate and iron(II)sulfate. It has been noticed that iron(II)ions oxidized before the adsorption on chitosan occurs. In comparison, the adsorption of nickel salt resulted in a smooth layer on the chitosan surface. SEM-EDX analysis revealed that sulfate adsorbs on the chitosan surface besides the metal cations used.

The modification of silica microparticles surface with a high number of amino/carboxylic groups of polymer chains represent an interesting route to obtain nanostructured composite materials aiming different applications. Herein, four weak polycations (PC) [polyethyleneimine (PEI), polylysine (PLL), polyvinylamine (PVAm), polyallylamine hydrochloride (PAH)] and one weak polyanion [polyacrylic acid (PAA)] were layer-by-layer deposited onto spherical silica to form composite microparticles. A strategy where each deposited polycation layer was chemically cross-linked with glutaraldehyde (GA) prior to the deposition of PAA layer was used, forming at the end silica//(PC GA/PAA)n composite microparticles. Finally, we investigated the particles towards their adsorption properties on metal ions (Cu2+, Pb2+, Ni2+, and Fe2+) from simulated and real surface water, as a potential application for the composite particles.

The study confirms the interaction of sulfate ions (SO42−) into the polymer chains of chitosan under acidic conditions. As a result the crystallinity of chitosan decreases with (1) increasing protonation of the amino groups and (2) increasing SO42− concentration. The adsorption of iron ions (Fe2+/3+) resulting from (FeSO4)aq onto the chitosan surface takes place incidentally by the oxidative effect of Fe2+/3+ with formation of orthorhombic α-FeOOH and γ-FeOOH. The separation of iron and sulfate ions correlates stoichiometrically. Chitosan with different degrees of deacetylation (DD) were used in order to investigate the influence of DD on the adsorption behavior of iron and sulfate ions. The higher the DD of chitosan, the more iron and sulfate ions can be adsorbed. Langmuir isotherms showed good agreement with the adsorption data obtained (qDD=90 %(Fe) = 2.36 mmol g-1; qDD=90 %(SO42−) = 2.58 mmol g-1). After adsorption process, the adsorber was analyzed extensively via X-ray diffraction, FTIR, 13C-NMR, SEM/EDX measurements and Mossbauer spectroscopy.

Polymers 10(7), - (2018). doi:10.3390/polym10070791 special issue: "Special Issue "Microgels and Hydrogels at Interfaces" / Guest Editor Dr. Patrick van Rijn, Department of BioMedical Engineering FB-40, University of Groningen/University Medical Center Groningen; Dr. Felix Plamper, Institute of Physical Chemistry, RWTH Aachen University", Published by MDPI, Basel

Composite microparticles of CaCO3 and two pectin samples (which differ by the functional group ratio) or corresponding nonstoichiometric polyelectrolyte complexes with different molar ratios (0.5, 0.9 and 1.2) are obtained, characterized and tested for loading and release of streptomycin and kanamycin sulphate. The synthesized carriers were characterized before and after drug loading in terms of morphology (by SEM using secondary electron and energy selective backscattered electron detectors), porosity (by water sorption isotherms) and elemental composition (by elemental mapping using energy dispersive X-ray and FTIR spectroscopy). The kinetics of the release mechanism from the microparticles was investigated using Higuchi and Korsmeyer–Peppas mathematical models.

The biodegradable polysaccharide chitosan possesses protonated and natural amino groups at medium pH values and has therefore been used as an adsorbing material for nickel salts in water treatment. Nickel is a problematic heavy metal ion which can cause various diseases and disorders in living organisms. Here, we show the influence of oxyanions (e.g., nitrate and sulfate) to the adsorption of nickel ions. Hence, simultaneously we are addressing the increasing global problem of nitrate and sulfate ion pollution in groundwater and surface water. A series of adsorption experiments was carried out in order to determine (i) the adsorption equilibrium, (ii) the adsorption capacity in dependence on the initial nickel ion concentration, and (iii) the influence of the anion presented in solution for the adsorption capacity. Surface morphology of chitosan flakes before and after the adsorption process has been studied with SEM-EDX analysis. The chitosan flakes exhibited promising adsorption capacities of 81.9 mg·g−1 and 21.2 mg·g−1 for nickel (sulfate) and nickel (nitrate), respectively. The calculated values of Gibbs free energy change ΔG0 confirm the higher adsorption of nickel ions in presence of sulfate ions. Hence, higher anion valence leads to a higher adsorption capacity.

As a consequence of mining, heavy metal ions can be exposed to the environment hence contaminate ground water and surface water amongst others. The natural polymer chitosan was proved to be an excellent adsorber material for the effective removal of iron and sulfate ions in batch as well as in column experiments. The adsorption behavior of iron ions, as well as sulfate ions was investigated by utilizing chitosan flakes as a natural adsorbent. The removal was studied using adsorbance measurements, SEM and SEM-EDX. The adsorption capacity of chitosan was determined at different times. The received adsorption capacities for iron ions were very promising with a maximum adsorption capacity of 85 mg/g and a rate of separation of 100%. The maximum adsorption capacity obtained for sulfate ions was 188.8 mg/g and a rate of 80%.

Five pectin samples – which differ by the methylation degree and/or amide content – were used to prepare inorganic/organic composites by CaCO3 mineralization from supersaturated solutions. The pectin chemical structure and concentration could control the composite superstructure by induction or orientation of crystal growth. The inorganic materials may also control CaCO3 polymorphism and morphologies and therefore different carbonate sources, such as Na2CO3, diethylcarbonate or ammonium carbonates, were used as modulators for crystal growth. The morphology of the new CaCO3/pectin composites was investigated by SEM and the polymorphs content by X-ray diffraction, as compared to bare CaCO3 samples prepared in similar conditions. The composites were tested as sorbents for Cu(II) and Ni(II) ions. Keywords: Pectin, CaCO3, Composite, Polymorph, Sorbent

Biologically degradable polymers based on renewable raw materials, such as polysaccharides, represent promising alternatives to synthetic polymers used as flocculants or stabilizing agents. Polysaccharides derived from potato starch have been modified with benzyl- and additionally cationic hydroxypropyl trimethyl ammonium groups of different degrees of substitution (DS). In this work these amphiphilic starch derivatives have been used to remove substances which impact negatively the paper production process when using recycled paper, so called stickies. Model suspensions have been studied using a multitude of different measurement techniques with the aim to predict a “sticky potential” and to reduce dissolved and colloidal substances such as micro-stickies. Systematic experiments studying the interactions between the novel amphiphilic starch derivatives and the model suspension have shown that dynamic surface tension is a very suitable property to characterize the surface active compounds in the model suspension giving additional information about the sticky potential of waste water, e.g. white water and offering a new and sensitive way to describe the parameter “hydrophobicity”. Moderately cationic and hydrophobic starch derivatives proved to be the most effective ones for sticky removal.

“Adsorption deinking” is a new concept for ink removal from suspensions using polymer particles instead of air bubbles (flotation) in a process with high efficiency, concerning the consumption of energy and water. We studied the influence of different papers and inks, of the deinking solution (compared with water), and of the duration of deinking. The process is characterized not only by the colour of polymer particles, but also by the properties in suspension such as charge, turbidity or particle size. Further it is shown, that dynamic surface tension is a useful tool to characterize not only the surfactant in suspension, but also its interaction with other substances (cellulose and ink). The efficiency of adsorption deinking is strongly influenced by the properties in suspension which depend on the type of paper.

For different practical applications, it is cardinal to maintain the stability of nanoparticles in aqueous suspension. The theoretical impact of pH and ultrasonication time on surface charge, particle size distribution and the dispersion stability of AEROSIL®OX 50 in water were evaluated, and a practical (centrifugal sedimentation analysis) test was used to determine the effects of concentration and molar mass of the polymer polyvinylpyrrolidone (PVP) at different pHs. It was observed that the size distribution of silica remains almost unaffected, but the surface charge increased with ultrasonication time up to 20 min and then leveled off. This increase in surface charge was proportional to the molar mass of the added polymer. The zeta potential increased with the increasing concentration of PVP in the silica suspension. This behavior is attributed to the adsorption of polymer over the surface of the particles. The suspensions were found to be the most stable, up to 36 %, at concentration (1 %) of PVP having higher molar masses. Furthermore, the addition of polymer strengthened the available agglomerates in the dispersion which resulted in the widening of the particles’ size distribution.

A novel strategy for faster and better flocculation in solid-liquid separation processes is reported: the use of the natural polyelectrolyte chitosan (CH2500) in combination with the biocompatible thermosensitive polymer poly(N-vinylcaprolactam) (PNVCL). Silica dispersions (Aerosil OX50) were used as model and evaluated by means of analytical centrifuge, laser diffraction, and turbidimetry studies. Results show that the sedimentation velocity is doubled by addition of PNVCL and that at 45°C the density of the sediment is 33% higher, as compared to the use of CH2500 only. This results from the temperature sensitive behavior of PNVCL that phase-separate expelling water at temperatures higher than its LCST (32–34°C) leading to compaction of the flocs. By using this strategy the sediment is more compact, contains less water, and contains a very small amount of biodegradable CH2500 and biocompatible PNVCL.

This study follows the possibility to tune the thermal stability of some CaCO3/polymer composites by crystal growth from supersaturated solutions controlled by polymer structure or by using nonstoichiometric polyelectrolyte complexes (NPECs). As the ratio between the organic and inorganic parts in the composites controls the Ca2+/polymer network crosslinking density, the CaCO3/polymer weight ratio was kept constant at 50/1, varying the initial concentration of the polyanions solutions (0.05 or 0.06 wt.%), the NPECs molar ratio , n+/n- (0.2 or 0.4), or the inorganic precursors concentration (0.25 or 0.3 M). Poly(2-acrylamido-2-methylpropanesulfonic acid-co-acrylic acid) (PSA) and chondroitin-4-sulfate (CSA) were used as polyanions. Some NPEC dispersions, prepared with the same polyanions and poly(allylamine hydrochloride) (PAH), were also used for calcium carbonate crystallization. The characteristics of the prepared composites were investigated by scanning electron microscopy (SEM), flow particle image analysis (FPIA), particles charge density (CD), zeta-potential (ZP). The thermal stability of the composite particles was investigated as compared to bare CaCO3 microparticles prepared at the same initial inorganic concentrations.

Modified starch with cationic as well as hydrophobic units can be used to remove negatively charged substances due to recycling processes of paper, so called stickies. The interactions between different types of starch and a negatively charged model suspension, obtained by heating up common newspaper, have been studied using polyelectrolyte titration, nephelometric turbidity measurement, and determination of the carbon content. In addition, we were able to show that the dynamic interface tension is a very suitable property to characterize the surface active compounds in the model suspension which allows receiving additional information about the sticky content of the waste water. Polyelectrolyte complexes were formed by adding cationic starch to the anionically charged model suspension. At a certain mixing ratio their precipitation leads to a significant reduction of the turbidity and the carbon content, whereas the surface tension increases due to sticky removal. Among starches with the same degree of cationic charge, those with the highest hydrophobicity were the most effective.

A novel strategy for faster and better flocculation in solid–liquid separation processes is reported: the use of a natural polyelectrolyte (chitosan) in combination with a biocompatible thermosensitive polymer [poly(N-vinylcaprolactam) (PNVCL)]. Clay dispersions were used as model and evaluated by means of analytical centrifuge, laser diffraction, streaming potential and turbidimetry studies. Results show that at 45 °C the density of the sediment is up to 15% higher, as compared to the use of chitosan only. This results from the temperature sensitive behaviour of PNVCL that phase separate expelling water at temperatures higher than it's LCST (32–34 °C). By using this strategy the sediment is more compact, contains less water, and contains a very small amount of biodegradable chitosan and biocompatible PNVCL.

The growth and properties of the polycation/azo dye multilayer thin films as a function of specific effects of the counterion (Cl−, Br−, SO42−), and the counterion concentration on the polycation conformation, the pure dye being always adsorbed from salt-free aqueous solution, have been investigated. A strong polycation containing 95 mol% of N,N-dimethyl-2-hydroxypropyleneammonium chloride units in the backbone and the azo dye Direct Red 80 were used as building blocks. An almost linear increase of the absorbance at 558 nm and of the layer pair thickness, measured by spectroscopic ellipsometry in wet state, with the increase of the layer pair number, were observed for all electrolytes. The specific effects of counterion type and concentration have been manifested in the amount of the dye adsorbed on each polycation layer, the thickness of the layer pair, and the surface morphology.

We present a rapid synthetic method for the development of hyperbranched PEIs decorated with different oligosaccharide architectures as carrier systems (CS) for drugs and bioactive molecules for in vitro and in vivo experiments. Reductive amination of hyperbranched PEI with readily available oligosaccharides results in sugar functionalized PEI cores with oligosaccharide shells of different densities. These core-shell architectures were characterized by NMR spectroscopy, elemental analysis, SLS, DLS, IR, and polyelectrolyte titration experiments. ATP complexation of theses polycations was examined by isothermal titration calorimetry to evaluate the binding energy and ATP/CS complexation ratios under physiological conditions. In vitro experiments showed an enhanced cellular uptake of ATP/CS complexes compared to those of the free ATP molecules. The results arise to initiate further noncovalent complexation studies of pharmacologically relevant molecules that may lead to the development of therapeutics based on this polymeric delivery platform.

Three ionic/nonionic random copolymers of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) with either t-butyl acrylamide (TBA) or methyl methacrylate (MM), were used in the preparation of some polyelectrolyte complex dispersions (PCD) with two strong polycations of integral type, poly(diallyldimethylammonium chloride) (PDADMAC), and an ionene type polycation, containing 95 mol% N,N-dimethyl-2-hydroxypropyleneammonium chloride repeat units (PCA5). The novelty of the paper is that PCDs with a high colloidal stability, both before and after the complex stoichiometry, were obtained even with hydrophilic/hydrophobic polyanions, with a high titrant addition rate (TAR), a less explored parameter, which allows a fine control of PCDs aggregation level, in salt-free aqueous solutions. The characteristics of PCDs were also correlated with the polyanion average charge density and the structure of the nonionic comonomer, at a constant TAR, the polyanion with the lowest charge density leading to the highest turbidities and the lowest colloidal stabilities. A mechanism of the PCDs colloidal stabilization as a function of TAR was suggested in the paper.

Flocculation efficiency of hydrophobically modified (HM) chitosan derivatives in comparison with commercial cationic polyacrylamide flocculant and unmodified (UM) chitosans varying in molecular weights and acetylation degrees has been evaluated in sodium dodecyl sulfate (SDS)-stabilized and surfactant-free oil-in-water emulsions at pH 4–9. It was found that due to the synergetic effect of cationic and hydrophobic functionalities HM-chitosans provide superior phase separation in SDS-stabilized systems at twice- and four-fold lower doses than UM-chitosan and cationic polyacrylamide, respectively. For this type of emulsions, pH had little influence on the efficiency of phase separation. In surfactant-free emulsions with low surface charge density of oil droplets, hydrophobic substitution had weaker effect on chitosan flocculation performance. Complete phase separation was reached only at pH > 7.5, and at UM and HM chitosan doses considerably higher than it was required for surface charge neutralization. This suggests that in surfactant-free emulsions hydrophobic interactions could not compensate a dramatic decrease of electrostatic attraction between polymers and droplet surface, thus, flocculation occurred mainly through the “sweep floc” process in contrast to the “charge patch” mechanism in SDS-stabilized systems.

Polycarboxybetaines – polymers containing a substituted ammonium moiety and a carboxylate group in every monomer units – show in aqueous solutions a pH-dependent intramolecular charge interactions. Here, we show that despite of this intramolecular charge effect mixing positively charge polycarboxybetaine and oppositely charged poly(maleic acid-co-propene) can yield polyelectrolyte complexes (PEC). Dynamic light scattering and viscometry has proved formation of highly swollen PEC nanoparticles with sizes in the range of 5–8 nm at n −/ n + ratio from 0.6 to 1.0. Significant difference in charge densities and molecular dimensions in the solution were suggested as the main reasons for deviation from 1:1 PEC stoichiometry.