Poly Sodium Research Articles

Fabrication and characterization of 3D scaffolds made from blends of sodium alginate and poly(vinyl alcohol)

Sodium alginate (SA) is a non-toxic, biocompatible and biodegradable natural polymer. It has good printability, which is why it is often used in inks for three-dimensional (3D) printing in tissue engineering fields. However, pure SA hydrogel has unstable mechanical properties. In this study, we fabricated a structurally stable 3D scaffold by blending SA with poly(vinyl alcohol) (PVA) to enhance the mechanical properties of the scaffold. Moreover, we characterized the surface morphology and various mechanical properties of the scaffolds using scanning electron microscopy, Fourier transform-infrared spectroscopy, thermogravimetric analysis and several mechanical tests. The SA/PVA scaffolds were mechanically more stable than the pure SA scaffold and are good candidate as implantable biodegradable scaffolds for tissue engineering and medical applications.

Moldable and Humidity-Responsive Self-Healable Complex from Lignosulfonate and Cationic Polyelectrolyte

We have developed a moldable and self-healable material from lignosulfonate by taking advantage of the ionic interactions between lignosulfonate and various cationic polyelectrolytes. Three lignosulfonate complexes with different cationic polyelectrolytes were prepared. The complex of sodium lignosulfonate (L-SO3Na) and poly(diallyldimethylammonium chloride) (PDADMACl) was deemed a promising moldable material based on its mechanical toughness in tensile tests (>3 MJ/m3). The mechanical properties of the L-SO3Na/PDADMACl complex were further characterized with regard to the effects of composition, the molecular weight of PDADMACl, and relative humidity. Our findings were as follows: (i) the addition of adequate amounts of lignosulfonate to PDADMACl improved the toughness of the complex (from 1.8 to 3.6 MJ/m3 at maximum), (ii) using higher-molecular-weight (>200,000) PDADMACl enhanced the mechanical properties of the complex, and (iii) increasing the relative humidity softened the complex through water absorption. The self-healing properties of the L-SO3Na/PDADMACl complex were also evaluated. The healing efficiency, in terms of toughness recovery, was only 14% at 50% relative humidity but increased to almost 100%, i.e., the sample did not break at the healed position, at 60% relative humidity. This study proposes the use of lignosulfonate as a component of humidity-responsive and completely self-healable materials.

Spectral Study on Association of Thiazine Dyes with Anionic Polymers

Feasible method of quantitative determination of anionic polymers in aqueous solutions was described using poly(styrene sulfonate) and poly(acrylate) sodium salts as an example. The method consists in absorbance measurements while titrating with thiazine dye. Volume of dye solution needed to attain specified value of absorbance is linearly dependent on polymer concentration. Optimal wavelengths are 666 nm and 640 nm for Methylene Blue dye and Toluidine Blue dye, respectively. Calibration plots are straight lines (r2 > 0.99) ensuring good accuracy of the method developed. Range of measurable concentrations is dependent on chosen value of end-point absorbance.

Selective adsorption and separation of illegal cationic dyes from foodstuffs with anionic polyelectrolyte functionalised metal-organic frameworks

ABSTRACTA novel adsorbent, poly(sodium 4–styrenesulfonate) modified MIL-101(Cr)–NH2, was successfully prepared. Owing to its high surface area and degree of negative surface charge, it enables effective adsorption and separation of illegal cationic dyes, such as rhodamine B, pararosaniline, and auramine O, from foodstuffs prior to high performance liquid chromatography analysis. Under optimised conditions, good linearity was obtained over 1.0–80.0 or 1.0–120 ng mL−1 with a correlation coefficient (R2) > 0.999. Limits of detection and limits of quantification of the three dyes were 0.28–0.65 and 0.94–2.13 μg kg−1, respectively. The recoveries of the three dyes in shrimp powder, chili powder, tofu sheets, and tomato sauce were in the range of 86.8–119.3%, suggesting that the developed method is a promising tool for accurate quantification of the three dyes at trace levels in foodstuffs.

Exploration of oligomeric sodium carboxylates as novel draw solutes for forward osmosis

FO technology has attracted growing attention in water treatment and desalination applications recently. The development of a suitable draw solute with high performance and low cost is therefore in high demand to facilitate practical FO applications. In this study, two oligomeric carboxylates — poly maleic acid sodium (PMAS) and poly(itaconate-co-acrylate) sodium [P(IA-co-AA)] with controllable molecular weights of 400–1000Da, are synthesized via one-step polymerization and employed as novel draw solutes for FO applications. The successful synthesis is confirmed via by various characterization techniques. The osmotic pressure, relative viscosity and FO performance of PMAS and P(IA-co-AA) draw solutions with different concentrations are studied systematically. Two types of FO membranes are employed, and their performance is compared using PMAS draw solution. With 0.5mol/kg PMAS draw solution and DI water feed solution, high water fluxes of 30.6 and 62.4LMH can be achieved using HTI-TFC and homemade PSf-TFC membrane in the FO tests, respectively. 0.5mol/kg PMAS draw solution is further studied for the desalination of 0.6mol/kg NaCl solution via FO, with a water flux of 6.63LMH obtained. The diluted PMAS solution after FO test can be recovered by nanofiltration with a high rejection rate. The excellent performance and available recovery route of the developed oligomeric carboxylates imply their great potential as promising draw solutes for FO applications.

A porous activated carbon supported Pt catalyst for the oxidative degradation of poly[(naphthaleneformaldehyde)sulfonate

Abstract Wet catalytic oxidation of sodium poly[(naphthaleneformaldehyde)sulfonate], a hazardous contaminant of wastewater streams from the textiles industry, by hydrogen peroxide under ambient conditions was explored over platinum supported on a porous activated carbon (PAC). Bulk and surface properties of the Pt/PAC catalyst were investigated by XRD, XPS, SEM, TEM, FTIR, EPR and thermogravimetric analysis. The parent PAC, derived from pyrolysis and subsequent activation of rice husks, exhibited significant micro- and mesoporosity, and a high degree of surface oxidation. Incorporation of 1.7 wt% Pt resulted in mesopore blockage, and a corresponding drop in surface area, associated with the formation of large ∼8 nm metallic nanoparticles. Poly[(naphthaleneformaldehyde)sulfonate] oxidative degradation was studied as a function of reactant concentration and solution pH, revealing first order decomposition kinetics and good activity over pH 3–9 at ambient temperature. Electron Paramagnetic Resonance (EPR)-DMPO spin trapping experiments confirm that oxidation of the organic pollutant proceeded via hydroxyl radical generation. The 1.7 wt% Pt/PAC catalyst showed excellent catalyst stability for five consecutive runs over 25 h in a fluidised bed reactor, delivering > 85% removal of 100 mg/L sulfonate with negligible Pt leaching or activity loss, and comparable performance for treatment of a real tannery effluent stream with a COD equivalent of 1860 mg/L.

Effect of Sodium Poly Acrylate on Water Holding Capacity of Soak Pits

Effect of Sodium Poly Acrylate on Water Holding Capacity of Soak Pits

Spherical α-Al2O3 suspensions layered sequentially with anionic and cationic polyelectrolytes: Chemistry, rheology and TEM images

The zeta potential-pH and yield stress-pH behaviour of washed spherical α-Al2O3 suspensions with and without adsorbed multilayer polyelectrolytes up to 4 layers of poly(styrene sulphonic acid) sodium salt or PSSNa (100 kDa) and polyethyleneimine or PEI (70 kDa) adsorbed sequentially were characterised. The maximum yield stress (τymax) of washed spherical α-Al2O3 is 81.8 Pa located at pHξ=0 at ~9.2. Particles with the first layer (layer 1) of PSSNa displayed negative zeta potential over the whole pH range of 3 to 8. Particles containing 3 layers with layer 3 being PSSNa also displayed negative zeta potential over the same pH range. The magnitude of the Layer 3 PSSNa is smaller. Similarly, the zeta potential remained positive for layer 2 and layer 4 PEI over the whole pH range of 3 to 8. At the dosage of 0.5 dwb% PSSNa and 0.1 dwb% PEI, monolayer coverage of PSSNa for layer 1 and 3 and of PEI for layer 2 and 4 should be achieved if the adsorption is uniform. The maximum yield stress of layer 1 PSSNa and layer 2 PEI was much larger than that without adsorbed additives despite the zeta potential being not zero. Additional attractive forces such as bridging, hydrophobic and hydrogen bonding must be present. TEM images showed that the adsorbed PSSNa-PEI layer surface is undulating and not uniform in thickness. This suggests that adsorption of these polyelectrolyes is not uniform. Extensive particle bridging showing the merging of layers at the interacting surface of the particles was observed from these TEM images. In contrast, α-Al2O3 suspensions with bilayer DIBMA-PEI, trilayer DIBMA-PEI-DIBMA and 4 layers DIBMA-PEI-DIBMA-PEI formed by 14 kDa DIBMA and 1.8 kDa PEI performed effectively as steric layer reducing the maximum yield stress significantly. TEM image of α-Al2O3 particles with bilayer DIBMA-PEI did not show the presence of polyelectrolyte layer suggesting that the polyelectrolyte layer is too thin to be observable.

Efficient prevention of nanomaterials transport in the porous media by treatment with polyelectrolytes

Contamination of soil by engineered nanomaterials (ENM) is an emergent environmental problem that urges the development of robust treatment protocols to prevent ENM transport through soil. We developed a method for efficient entrapment and retention of ENM in solid porous media of quartz sand with grain size of 300–500 μm used as a simple model of soil and studied the transport properties of multi-walled carbon nanotubes, fullerenes, silica and gold nanoparticles through the sand-packed column by UV–vis and fluorescent spectroscopy. The treatment of ENM-contaminated porous media with a mixture of oppositely charged polyelectrolytes, cationic poly(diallyldimethylammonium chloride) and anionic poly(acrylic acid) sodium salt, dissolved in NaCl solution followed by dilution in the column results in strong electrostatic interaction between the polyelectrolytes and a formation of inter-polyelectrolyte complexes (IPEC) that induce flocculation of ENM and adsorption to the surface of sand. The method demonstrates excellent ENM entrapment efficiency (>90%) and high capacity of several grams of ENM per 1 g of polyelectrolytes. The IPEC network formed after the treatment also serves as an efficient protection barrier for newly added ENM contaminants. The method is universal for various types of ENM (carbon ENM, metal and oxide nanoparticles) and equally efficient for distilled water, tap water, or lake water eluents.

Chitosan based copolymer-drug conjugate and its protein targeted polyelectrolyte complex nanoparticles to enhance the efficiency and specificity of low potency anticancer agent

The effective delivery of low potency anticancer drug is a major challenge. The present study introduces the novel chitosan-polylactic acid (CS-PLA)-drug conjugate and its transferrin receptor targeted polyelectrolyte complex nanoparticles (PEC Nps), encapsulating free drug to increase its potency and specificity. The model drug curcumin (CR) was used and incorporated in this system in both conjugated and encapsulated form. The synthesis of CS-PLA-CR copolymer was confirmed by 1H NMR, FTIR, UV–visible spectrum, DSC thermogram and zeta potential. Further, the nanoparticles engulfing free CR, with average 340 nm particle sizes, were prepared through simple ionic gelation technique utilizing positive charges on copolymer by polyanion sodium alginate (CS-PLA-CR/SA PEC Nps). The prepared Nps showed the high CR content of over 92% with extended period of CR release (60% and 85% at pH 7.4 and 5 respectively even after 8 days). The results were compared with the unmodified CS (without PLA) as a control to understand the effect of PLA side chain. Transferrin (Tf) conjugation on PEC Nps displayed superior cytotoxicity and cellular uptake compared to non-targeted Nps on MCF-7 cell line. Thus, CR loaded Tf-CS-PLA-CR/SA PEC Nps may provide an efficient and targeted delivery for cancer treatment.

Swelling Degree and Diffusion Parameters of Poly (Sodium Acrylate-Co-Acrylamide) Hydrogel for Removal of Water Content From Biodiesel

Hydrogels particles swell in the presence of an adequate solvent and soak the solvent into the cross-linked matrix of the particle, therefore they have great potential to remove soluble and insoluble water from liquid fuels, such as biodiesel, diesel and blends. In this paper, kinetic parameters and hydrophilic properties of polyacrylamide and poly(sodium acrylate-co-acrylamide) (AAm-co-SA) hydrogels were investigated to provide data for future equipment designs and devices that use these materials in removing water from Biodiesel. New hydrogels synthesized with sodium acrylate and acrylamide obtained a swelling ratio (weight of the swollen sample to that of the dry sample) of W8=108.8 g water/g hydrogel, much higher than hydrogels developed in previous research (W8=14.36 g/g) to remove water from biodiesel. Preliminary tests with the new hydrogel developed showed its ability to reduce water content from biodiesel.

Fabrication of a Novel Beta Tricalcium Phosphate/Sodium Alginate/Poly(D,L-lactic acid) Composite Microsphere and Its Drug Releasing Property.

Bone repair microspheres have been widely studied due to their convenience during clinical operations. In this study, beta tricalcium phosphate/sodium alginate/poly(D,L-lactic acid) (β-TCP/SA/PDLLA) composite microspheres were successfully prepared using the liquid droplet method. Then, β-TCP/SA/PDLLA composite microspheres were soaked in simulated body fluids (SBF) for 7 days, and tested in an X-ray diffractometer (XRD). The results indicated that sodium alginate (SA) and poly(D,L-lactic acid) (PDLLA) are not limiting factors for the transformation of β-TCP to HA. Since sodium ions and bicarbonate ions were abundant, the final products were not pure HA but (Na, CO3)-substituted HA. When soaked in SBF, the structure of β-TCP/SA/PDLLA composite microspheres remained stable for at least 14 days suggesting that their anti-washout ability was suitable. Furthermore, the absence of calcination during the preparation of β-TCP/SA/PDLLA composite microspheres enabled the easy incorporation of vancomycin into the microspheres in situ at a final embedding ratio of 26.18%. Furthermore, the β-TCP/SA/PDLLA composite microspheres possessed excellent sustained drug release capability, and the release of vancomycin (92.8 wt.%) lasted for almost 168 h. Our results suggest that the β-TCP/SA/PDLLA composite microspheres could be used as a promising graft material particularly for bone repair.

Characterizations of hyaluronate-based terpolymeric hydrogel synthesized via free radical polymerization mechanism for biomedical applications.

In the present study, a novel terpolymeric hydrogel was developed using sodium hyaluronate (HA), 2-hydroxyethyl acrylate (2-HEA), and poly(ethylene glycol) diacrylate (PEGDA) via free radical polymerization for biomedical applications. To achieve elasticity, swelling ability, porous architecture and sufficient gel strength, hyaluronate was chemically modified by grafting and crosslinking methods using 2-HEA and PEGDA, respectively. The structure and compositions of the fabricated terpolymer (HA-g-p(2-HEA)-x-PEGDA) were verified by FTIR, 1H HR-MAS-NMR, and TGA analyses. The surface morphology and cross-section of the hydrogel was detected by SEM analysis. The gel nature of terpolymer in aqueous medium at 37 °C was confirmed from swelling study, and rheological experiment. Non-cytotoxicity and biocompatibility of the HA-g-p(2-HEA)-x-PEGDA hydrogel were ascertained by in vitro mouse osteoblastic cells (MC3T3) proliferation, and viability studies. Hematoxylin and eosin Y, and Masson's trichrome stainings were performed to show tissue regeneration ability on the prepared hydrogel. In vitro release results of proangiogenic drug-dimethyloxalylglycine (DMOG), and antibiotics-tetracycline (TCN) showed sustained release behaviour from the prepared hydrogel under different pHs at 37 °C. The mathematical models fitted data imply that both DMOG and TCN release follow first order kinetics, while, the release mechanism is primarily controlled by diffusion as well as erosion process. Finally, the novel biocompatible HA-g-p(2-HEA)-x-PEGDA gel, which showed sustained drugs release, and regeneration ability of extracellular matrix and collagen, could be employed in biomedical applications, especially, for the delivery of DMOG/TCN, and in tissue engineering.

Dispersion copolymerization of acrylamide and sodium 2-acrylamido-2-methylpropanesulfonate in aqueous salt solution stabilized with a macro-RAFT agent

Dispersion copolymerization of acrylamide (AM) and sodium 2-acrylamido-2-methylpropanesulfonate (AMPSNa) in aqueous ammonium sulfate (AS) solution was performed without mechanical stirring using a macro-RAFT agent sodium poly(2-acrylamido-2-methylpropanesulfonate) trithiocarbonate (PAMPSNa-TTC) as the stabilizer and 2,2′-azobis(2-methylpropionamide) dihydrochloride as the initiator. The effects of various polymerization parameters were systematically investigated regarding dispersion stability, particle size, molecular weight and apparent viscosity. A new mechanism for particle formation and the particle stability of aqueous dispersion polymerization was proposed.

Effect of Eu(III) and Tb(III) chloride on the gelification behavior of poly(sodium acrylate)

Supramolecular gels are an important class of soft materials: they are basically formed by solvent molecules inside in a 3D network structure and can be considered from soft and weak to hard and tough, depending on the respective mechanical properties. The gelation process can be accomplished in different ways using, for example, the interaction between a charged polymer and a metal ion. In this work, the interaction between poly(acrylic acid) sodium salt (PSA) and the trivalent ion (Eu3+ and Tb3+), to form luminescent gels, has been studied. For that, a phase diagram for polymer-ion mixture was constructed showing that for high molar ratios Ln3+/PSA different phase transitions occur. We have focused our work in the region where the formation of weak and strong gels is occurring. The phase transitions have been assessed by rheological and luminescence measurements. From rheological measurements, we have found that the mechanical strength of gels increases by increasing the concentration of PSA, since the elastic module (G´) increases when the concentration of PSA increases. A similar trend is found in yield stress values, from which the gel begins to behave as a liquid. Thus, the higher the concentration of PSA the higher is the yield stress. The frequency sweeps shows that Ln3+/PSA gels and weak gels exhibit a rheological solid-type behavior, with a storage module (G´) predominating over loss modulus (G´´) in the studied frequency. The formation of the gel phase can also be followed by fluorescence spectroscopy. It can be observed that the emission of fluorescence increases by increasing the molar ratio Ln3+/PSA. Such behavior may be explained by the binding of Ln3+ to deprotonated PSA and a decrease in the number of coordinated water molecules. However, the formation of gel phase is reversible and dependent on the Ln3+ concentration. In fact, by increasing the molar ratio values above a certain critical point, disaggregation of the gel structure occurs, mainly due to electrostatic repulsions between ions Ln3+ and Ln3+/PSA aggregates; this is supported by the decrease in the emission of fluorescence of Ln3+ mixed solutions. The effect of Ln3+ in the PSA gel formation mechanism is complemented with the analysis of FTIR, SEM and EDS mapping data.

Solvothermal synthesis and electrochemical properties of Na2CoSiO4 and Na2CoSiO4/carbon nanotube cathode materials for sodium-ion batteries

The commercialization of large-scale energy storage systems has renewed the scientific interest on electrode materials for sodium-ion batteries (SIBs). Polyanionic sodium orthosilicates [Na2M(SiO4)] are an interesting group of SIB cathode materials with high redox potentials via a two-electron redox process, and their three-dimensional framework. However, studies on these materials are limited due to difficulties in synthesizing them in stable and electrochemically desirable phase. Exhibiting rich polymorphism, orthosilicates undergo irreversible structural changes during processing and/or cycling. Here, we report a solvothermal process, which yields in situ carbon-coated Na2CoSiO4 with monoclinic structure. Besides physical characterization, we discuss its electrochemical performance in coin-cell configuration vs. Na anode. Na2CoSiO4 exhibits significantly lower polarization (0.15 V) than Na2FeSiO4 and Na2MnSiO4. As polyanionic compounds are poor electronic conductors with sluggish redox kinetics, we observe that these limitations could be overcome in Na2CoSiO4 by incorporating functionalized multi-walled carbon nanotubes (MWCNTs). The Na2CoSiO4/MWCNT composite cathode reversibly delivers 125 mAh g−1 at C/20 rate, almost 50% more than pristine Na2CoSiO4. We also provide insights into the Na+ diffusion and exchange current by applying electrochemical impedance spectroscopy (EIS), revealing that the Na+ diffusion coefficient increases by one order while the exchange current doubles when functionalized MWCNTs are added to Na2CoSiO4.

Experimental and computational investigation of reduced graphene oxide nanoplatelets stabilized in poly(styrene sulfonate) sodium salt

The production of large-area interfaces and the use of scalable methods to build up designed nanostructures generating advanced functional properties are of high interest for many materials science applications. Nevertheless, large-area coverage remains a major problem even for pristine graphene, and here we present a hybrid, composite graphene-like material soluble in water that can be exploited in many areas such as energy storage, electrodes fabrication, selective membranes and biosensing. Graphene oxide (GO) was produced by the traditional Hummers’ method being further reduced in the presence of poly(styrene sulfonate) sodium salt (PSS), thus creating stable reduced graphene oxide (rGO) nanoplatelets wrapped by PSS (GPSS). Molecular dynamics simulations were carried out to further clarify the interactions between PSS molecules and rGO nanoplatelets, with calculations supported by Fourier transform infrared spectroscopy analysis. The intermolecular forces between rGO nanoplatelets and PSS lead to the formation of a hybrid material (GPSS) stabilized by van der Waals forces, allowing the fabrication of high-quality layer-by-layer (LbL) films with poly(allylamine hydrochloride) (PAH). Raman and electrical characterizations corroborated the successful modifications in the electronic structures from GO to GPSS after the chemical treatment, resulting in (PAH/GPSS) LbL films four orders of magnitude more conductive than (PAH/GO).

Doubly pH Responsive Emulsions by Exploiting Aggregation of Oppositely Charged Nanoparticles and Polyelectrolytes.

We present a simple and modular approach to realize highly stable pH responsive Pickering emulsion from mixtures of commercially available oppositely charged nanoparticle and polyelectrolyte. While highly charged nanoparticles and polyelectrolytes when used solely do not stabilize emulsions, we show that the electrostatic attraction between oppositely charged nanoparticles and polyelectrolytes can be exploited to formulate emulsions with long-term stability of up to 8 months. The Ludox CL nanoparticles and poly(4-styrenesulfonate) sodium salt (PSS) when dispersed in aqueous solution at pH 2-11 form particle polyelectrolyte complexes (PPCs) due to heteroaggregation. These complexes are effective in stabilizing oil-in-water Pickering emulsions. We demonstrate that this is due to the formation of weakly charged complexes that are surface active and hence readily adsorbed to the oil-water interface created during emulsification. We show that the composition of nanoparticles and polyelectrolytes in the mixture as well as the pH can be tuned to control the average diameter of the emulsions droplets. Immediate destabilization and doubled responsiveness of the emulsions stabilized by particle polyelectrolyte complexes are illustrated by changing the pH of the stable emulsions formed at intermediate pH to either 1 or 13. The aggregation behavior of nanoparticle-polyelectrolyte mixtures and the effect of various parameters such as mixing fraction, pH, and energy input on the formation of Pickering emulsions is discussed. Furthermore, we show that the formation of near charge neutral aggregates that exhibit optimal wetting conditions is a requirement to accomplish emulsion formation. The visualization of particle polyelectrolyte complexes around the emulsion droplets, their morphology prior to emulsification, and their wetting properties are also investigated to elucidate the mechanism of emulsification.

Reaction enthalpy from the binding of multivalent cations to anionic polyelectrolytes in dilute solutions.

Dilute solutions of sodium poly(styrene sulfonate) (NaPSS) in the presence of Al3+, Ca2+, and Ba2+ were analysed by means of isothermal titration calorimetry (ITC) in order to investigate the heat effect of bond formation between those cations and the anionic SO3- residues of NaPSS. The selection of the cations was guided by the solution behavior of the corresponding PSS salts from a preceding study [M. Hansch et al., J. Chem. Phys. 148(1), 014901 (2018)], where bonds between Ba2+ and anionic PSS showed an increasing solubility with decreasing temperature and Al3+ exhibited the inverse trend. Unlike to Al3+ and Ba2+, Ca2+ is expected to behave as a purely electrostatically interacting bivalent cation and was thus included in the present study. Results from ITC satisfactorily succeeded to explain the temperature-dependent solution behavior of the salts with Al3+ and Ba2+ and confirmed the non-specific behavior of Ca2+. Additional ITC experiments with salts of Ca2+ and Ba2+ and sodium poly(acrylate) complemented the results on PSS by data from a chemically different polyanion. Availability of these joint sets of polyanion-cation combinations not only offers the chance to identify common features and subtle differences in the solution behavior of polyelectrolytes in the presence of multi-valent cations but also points to a new class of responsive materials.

Molecular interactions in self-assembled nano-structures of chitosan-sodium alginate based polyelectrolyte complexes

We report here the self-assembled structures of polyelectrolyte complexes (PECs) of polyanionic sodium alginate with the polycationic chitosan at room temperature. The PECs prepared at different pH values exhibited two distinct morphologies. The chitosan-alginate PECs self-assembled into the fibrous structure in a low pH range of pH3 to 7. The PECs obtained at high pH series around pH8 and above resulted in the formation of colloidal nanoparticles in the range of 120±9.48nm to 46.02±16.66nm. The zeta potential measurement showed that PECs prepared at lower pH (pH<6) exhibited nearly neutral surface charge, whereas PECs prepared at higher pH than 6 exhibited highly negative surface charge. The molecular interactions in nano-colloids and fibers were evaluated using FTIR analysis. The results attest that the ionic state of the chitosan and alginate plays an important role controlling the morphologies of the PECS. The present study has identified the enormous potential of the polyelectrolytes complexes to exploit shape by the alteration of ionic strength. These findings might be useful in the development of novel biomaterial. The produced fibers and nanocolloids could be applied as a biomaterial for tissue engineering and drug delivery.