Poly Diallyldimethylammonium Chloride Research Articles

Synthesis and evaluation of cationic polyacrylamide and polyacrylate flocculants for harvesting freshwater and marine microalgae

• Cationic PAETAC & PAmPTAC were synthesized by UV-induced radical polymerization. • New polymers showed good flocculation performance of freshwater & marine microalgae. • Optimal doses of PAETAC were 50 and 4.8 mg/g for C. vulgaris & P. purpureum. • PAETAC and PAmPTAC produced stable flocs, supporting simple dewatering step. This study addresses the challenge of microalgae harvesting through the development of flocculants. Two positively charged cationic polymers including poly[2 (acryloyloxy)ethyl]trimethylammonium chloride (PAETAC) and poly(3 acrylamidopropyl)trimethylammonium chloride (PAmPTAC) were synthesized using the UV-induced radical polymerization, for harvesting both freshwater and marine microalgae. The results show that the synthesized polymers have excellent flocculation performance for both freshwater green microalgae ( Chlorella vulgaris) and marine red microalgae ( Porphyridium purpureum). PAETAC outperformed PAmPTAC for both Chlorella vulgaris and Porphyridium purpureum microalgae. The optimal PAETAC doses for Chlorella vulgaris and Porphyridium purpureum microalgae were 50 and 4.8 mg/g of dry biomass while the optimal PAmPTAC doses were 252 and 35 mg/g of dry biomass respectively. Additionally, the floc formation with the PAETAC was more stable than PAmPTAC, which supported the dewatering step via sieving. The superior performance can be attributed to the higher molecular weight of the PAETAC polymer when compared to the PAmPTAC polymer. In comparison to commercially available polydiallyldimethylammonium chloride (PolyDADMAC), the newly synthesised PAETAC and PAmPTAC polymers demonstrated superior flocculation efficiency at a lower dose. The findings of this study established a platform technology for designing and synthesising cationic flocculants for use in microalgae harvesting.

Rethinking the timing of flocculant addition during activated sludge dewatering

The high water content and huge volume of activated sludge greatly increase the costs for disposal and transportation. Combined use of acid and flocculant can effectively enhance the sludge dewatering performance. In the present work, the influence of dosing order of acid and polydiallyldimethylammonium chloride (PDMDAAC, a typical flocculant) on sludge dewaterability was investigated. Results showed that the PDMDAAC + acid process exhibited a better dewatering capability than the acid + PDMDAAC process under the identical conditions, which indicated that PDMDAAC should be dosed before acid treatment. The water content decreased from 75.4% to 67.8% for the PDMDAAC + citric acid process. The potential mechanisms behind sludge dewatering were explored, and the decomposition of tightly-bound extracellular polymeric substances (TB-EPS), increased particle size and aggregated morphology of the sludge flocs were found to be closely correlated with the enhanced dewatering performance. These results confirmed that the PDMDAAC + acid treatment achieved a better performance in enhancing sludge dewatering, and will help to understand the combined conditioning process of acid and flocculant.

Modification of Polydiallyldimethylammonium Chloride with Sodium Polystyrenesulfonate Dramatically Changes the Resistance of Polymer-Based Coatings towards Wash-Off from Both Hydrophilic and Hydrophobic Surfaces.

Polymer coatings based on polycations represent a perspective class of protective antimicrobial coatings. Polydiallyldimethylammonium chloride (PDADMAC) and its water-soluble complexes with sodium polystyrenesulfonate (PSS) were studied by means of dynamic light-scattering, laser microelectrophoresis and turbidimetry. It was shown that addition of six mol.% of polyanion to polycation results in formation of interpolyelectrolyte complex (IPEC) that was stable towards phase separation in water-salt media with a concentration of salts (NaCl, CaCl2, Na2SO4, MgSO4) up to 0.5 M. Most of the polyelectrolyte coatings are made by layer-by-layer deposition. The utilization of water-soluble IPEC for the direct deposition on the surface was studied. The coatings from the PDADMAC and the PSS/PDADMAC complex were formed on the surfaces of hydrophilic glass and hydrophobic polyvinylchloride. It was found that formation IPEC allows one to increase the stability of the coating towards wash-off with water in comparison to individual PDADMAC coating on both types of substrates. The visualization of the coatings was performed by atomic force microscopy and scanning electron microscopy.

The Synergetic Impact of Anionic, Cationic, and Neutral Polymers on VES Rheology at High-Temperature Environment.

Hydraulic fracturing operations target enhancing the productivity of tight formations through viscous fluid injection to break down the formation and transport proppant. Crosslinked polymers are usually used for desired viscoelasticity of the fracturing fluid; however, viscoelastic surfactants (VES) became a possible replacement due to their less damaging impact. To design a fracturing fluid with exceptional rheological and thermal stability, we investigated mixing zwitterionic VES with carboxymethyl cellulose (CMC), hydroxyethylcellulose (HEC), or a poly diallyl dimethylammonium chloride (DADMAC) polymers. As a base fluid, calcium chloride (CaCl2) solution was prepared with either distilled water or seawater before adding a polymer and the VES. A Chandler high-pressure, high-temperature (HPHT) viscometer was used to conduct the viscosity measurements at a shear rate of 100 1/s. It has been found that adding 1% CMC polymer to 9% (v/v) VES increases the viscosity more compared to 10% (v/v) VES at reservoir temperatures of 143.3 °C. On the other hand, adding only 1.0% of HEC to 9% (v/v) VES doubled the viscosity and proved more effective than adding CMC. HEC, nevertheless, reduced the system stability at high temperatures (i.e., 148.9 °C). Adding DADMAC polymer (DP) to VES increased the system viscosity and maintained high stability at high temperatures despite being exposed to saltwater. CaCl2 concentration was also shown to affect rheology at different temperatures. The improved viscosity through the newly designed polymer can reduce chemical costs (i.e., reducing VES load), making it more efficient in hydraulic fracturing operations.

Determination of ultrahigh molar mass of polyelectrolytes by Taylor dispersion analysis

Taylor dispersion analysis (TDA) was successfully applied to obtain broadly distributed, ultrahigh molar masses of industrial anionic polyacrylamides (IPAMs) up to 25×106g/mol, far beyond the limits of Size Exclusion Chromatography (SEC) (about 7.3×106g/mol for anionic polyacrylamides standards (APAM)). Two protocols of TDA differing in capillary surface and rinsing procedure were employed: (i) bare fused silica capillaries under intensive between-run rinsing with 1M NaOH, and (ii) fused silica capillaries coated with polyelectrolyte multilayers composed of polydiallyldimethylammonium chloride polycation and sodium polystyrenesulfonate polyanion under simple rinsing with background electrolyte. Both cases led to similar results and in agreement with those obtained by static light scattering, the rinsing capillary step being much shorter in the second case (8min instead of 30min). The data processing of the obtained taylorgrams was realized using multiple-Gaussian fitting of the overall taylorgrams, by separating the contribution of low molar mass impurities from the polymeric profiles, and by determining the mean hydrodynamic radii and diffusion coefficients of the polymers. The molar masses of ultra-high molar mass industrial anionic polyacrylamides (IPAM) were derived from the hydrodynamic radii according to logRh versus logMw linear correlation established with APAM standards. Compared to capillary gel electrophoresis for which the size separation was only feasible up to Mw ∼ 10×106g/mol due to field induced polymer aggregation, TDA largely extended the range of accessible molar mass with easy-to-run and time saving assays.

Synthesis of beta nanozeolite aggregates with hierarchical pores via steam-assisted conversion of dry gel and their catalytic properties for Friedel-Crafts acylation

Modulation of the porosity and acidity of zeolites is a very attractive subject for designing highly efficient solid-acid catalysts. In this work, Beta nanozeolite aggregates with hierarchical porous structure were synthesized via steam-assisted conversion (SAC) of dry gel in presence of seeds and a cationic polymer of polydiallyldimethylammonium chloride (PDAD). The influence of various synthesis parameters, such as the alkalinity, the contents of PDAD and zeolite seeds, and the crystallization conditions (temperature, water/dry gel ratio and time) on the formation of Beta zeolites was studied by combining a variety of characterization techniques. The SAC-synthesized Beta zeolites (S-Beta) are assembled from ultra-small nanocrystals around 10 nm to form self-sustaining micron-sized zeolitic aggregates, and possess abundant interconnected mesopores and relatively mild acidity. Compared with the conventional Beta zeolite, S-Beta aggregates show much higher catalytic activity for the Friedel-Crafts acylation of anisole with acetic anhydride. The excellent catalytic performance of S-Beta should be mainly attributed to the enhanced mass transport ability for reagents as well as the mild acidity that can avoid the rapid deactivation of the catalyst under the test conditions.

A novel label-free colorimetric polyA aptasensing approach based on cationic polymer and silver nanoparticles for detection of tobramycin in milk

In this study, a novel colorimetric bioassay method was developed for the sensitive determination of tobramycin (TOB). To detect TOB, silver nanoparticles (AgNPs) were decorated with TOB-specific aptamers (apt), and positively charged poly diallyl dimethyl ammonium chloride (PDDA) was used. As long as tobramycin is not present in the assay system, PDDA can coalesce with the aptamer, and AgNPs would remain stable (λmax = 400 nm) in the dispersed system against PDDA-induced aggregation. When TOB is added, aptamer can bind to the compound, which leads to release of PDDA and subsequent aggregation of AgNPs (λmax = 540 nm). This remarkable change, as a colorimetric analytics signal, can be used for quantitative analysis of TOB. TOB can be detected by this highly sensitive colorimetric aptasensor with a limit of detection (LOD) of 70 pM. Furthermore, TOB can be detected with the naked eye at concentrations above 1 nM.

A versatile strategy for loading silica particles with dyes and quantum dots

A simple and inexpensive method for the controlled loading of silica particles with dyes and nanocrystals is presented. Polydiallyldimethylammonium chloride is used as a positively charged bridge to facilitate electrostatic adsorption of negatively charged dyes onto negatively charged silica microspheres. The particles are subsequently coated with a further silica shell to protect the dyes against chemical degradation and leakage and this shell affords a unform particle surface independent of its doping. This encapsulation method is highly versatile and can be extended to doping with semiconductor nanocrystals, which we demonstrate using CdSe/ZnS core/shell quantum dots. The synthesis steps and end products are characterized with electron microscopy, optical spectroscopy and the electrokinetic potential of the colloidal suspensions. We show that the particles adapt the optical properties of their dopants and are resistant to degradation, dopant leakage and show reasonable emission even at acidic pH values due to the protective shell.

Adherable Temperature Sensor to a Porous Structure of Fiber via Reduced Graphene Oxide and Poly(diallyldimethylammonium chloride) Complex

Abstract We present an adherable temperature sensor on aramid fiber filament coated with reduced graphene oxide (rGO) and poly(diallyldimethylammonium chloride) (PDADMAC) complex. The PDADMAC dispersed in a graphene oxide aqueous solution was dried and reduced to an rGO-PDADMAC complex with laser irradiation. The rGO-PDADMAC sensor was characterized with a scanning electron microscope and Raman spectroscopy. The rGO-PDADMAC sensor showed a negative temperature coefficient resistance change at 40% relative humidity (RH). Furthermore, the sensor successfully detected 58% resistance variation from 25°C to 100°C as the pristine rGO sensor showed 61% resistance variation on a rigid surface. Also, the rGO-PDADMAC sensor demonstrated long-term reliability of 3% sensitivity for 7 days in normal room conditions at 25°C and 40% RH. Additionally, the adherable temperature sensor of the rGO-PDADMAC complex viscous to the porous structure of aramid fiber detected 55% sensitivity from 25°C to 100°C.

Hot-pressing polyelectrolyte complexes into tunable dense saloplastics

Salt-plasticized polyelectrolyte complexes of sodium polystrenesulfonate (Na-PSS) and polydiallyldimethylammonium chloride (PDADMAC) were found to be fully dense (non-porous) when hot-pressed under optimal conditions. The quality of these saloplastics is determined by the molecular weights of polyelectrolytes, the salt type and concentration, as well as processing conditions like pressure and temperature. Higher molecular weights give more compact precipitates that are easy to process while decreasing the molecular weight led to particulate ones. Both the type and concentration of salt on complex formation and doping are explored and are found to play an equally important role. The effects of individual hot-pressing parameters, namely, pressure and temperature are studied thoroughly, facilitating the formation of uniform free-standing films over a wide range of thicknesses from 8 μm to 1 mm. For the first time, saloplastics were studied as free-standing films that are dense even at the nanometer scale. In their dry states, they were brittle and strong, showing a uniform Young's modulus over a range of relevant thicknesses, while the wet states were rubbery and elastic, showing a decreasing trend with thickness. In the wet state, the inverse trend is due to the quicker drying of thin films. Within a single hot-pressing step, protruding shapes and structures from the surface were efficiently made at different length scales. Moreover, saloplastics were also successfully reinforced with thin woven and nonwoven fibers for enhanced tensile strengths, higher than conventional thermoplastics. Overall, this work demonstrates an easy approach to fabricate dense saloplastics and their unique mechanical properties.

Polymeric diallyl quaternary ammonium salts for inhibiting banana Fusarium wilt

Banana Fusarium wilt is a typical soil-borne pathogen disease caused by Fusarium oxysporum f. sp. cubense (Foc) and is difficult to control because Foc conidia can survive for many years in soil. Thus, the inhibition of Foc conidia in soil would be an effective and possible way to control banana Fusarium wilt. In this work, three kinds of poly(N,N-diene propyl quaternary ammonium salts) (PDPQASs), namely, poly(methyl butyl diallyl ammonium chloride) (PM), poly(methyl benzyl diallyl ammonium chloride) (PB) and poly(dimethyl diallyl ammonium chloride) (PD), were synthesized, and the antifungal activities on Foc4, the adsorption and leaching properties in soil, and the biotoxicities on silkworms, zebrafish and mice were evaluated. It was found that the three kinds of PDPQAS showed obvious and stronger inhibiting effects on Foc4 conidia, and they were essentially nontoxic to silkworms and mice. Their toxicities were much lower than that of benzalkonium chloride (BC, a typical commercial small molecular QAS) to zebrafish, in which PB showed the best comprehensive properties in antifungal activities and biotoxicities. Benefitting from the stronger polymer-soil interaction, PB could absorb in soil more easily and hardly be leached from the soil, which helped PB stay in the soil more stably and effectively inhibited Foc4 conidia in the long term, giving PB a potential application in the control of banana Fusarium wilt.

Influence of molecular weight of polycation polydimethyldiallylammonium and carbon nanotube content on electric conductivity of layer-by-layer films

For biological and engineering applications, nm-thin films with high electrical conductivity and tunable sheet resistance are desirable. Multilayers of polydimethyldiallylammonium chloride (PDADMA) with two different molecular weights (322 and 44.3 kDa) and oxidized carbon nanotubes (CNTs) were constructed using the layer-by-layer technique. The surface coverage of the CNTs was monitored with a selected visible near infrared absorption peak. Both the film thickness and the surface coverage of the CNTs increased linearly with the number of CNT/PDADMA bilayers deposited (film thickness up to 80 nm). Atomic force microscopy images showed a predominantly surface-parallel orientation of CNTs. Ohmic behavior with constant electrical conductivity of each CNT/PDADMA film and conductivity up to 4 · 103 S/m was found. A change in PDADMA molecular weight by almost a factor of ten has no effect on the film thickness and electrical conductivity, only the film/air roughness is reduced. However, increasing CNT concentration in the deposition dispersion from 0.15 up to 0.25 mg/ml results in an increased thickness of a CNT/PDADMA bilayer (by a factor of three). The increased bilayer thickness is accompanied by a decreased electrical conductivity (by a factor of four). The decreased conductivity is attributed to the increased monomer/CNT ratio.

Synthesis of a Novel Water‐Soluble Graft Copolymer for Mineral Ore Beneficiation and for River Water Treatment towards Drinking Water Augmentation

AbstractIn this research paper we endeavor to publish our work on novel non acrylamide based flocculant which does not threat any acrylamide release and thus is inherently safer. A novel flocculant ‘Polydiallyldimethylammonium Chloride grafted Carboxymethyl Cellulose [CMC‐g‐P(DADMAC)]’ was synthesized by both conventional and microwave assisted method. Both the synthesis were optimized in terms of synthesis parameters. The various grades synthesized were characterized through standard characterization techniques such as Scanning electron microscope (SEM), Fourier transformation Infrared spectroscopy (FTIR), Elemental analysis, X‐ray diffraction (XRD) analysis, Thermal gravimetric analysis (TGA) Differential scanning calorimetry (DSC) analysis etc. Further, the various grades of the graft copolymers were optimized as flocculant by ‘standard Jar test’ and ‘Settling test’ protocols in river water, Kaolin, iron ore and coal fine suspension. The maximum flocculation efficacy achieved was 80.9 % (Kaolin suspension), 83.6 % (coal fine suspension), 79.5 % (Iron‐ore suspension) and 68.3 % (River water).

Generating nanocrystalline SAPO-34 through bead-milling and porogen-assisted recrystallization: Structural evolution and catalytic consequence in dimethyl ether-to-olefin conversion

Mechanochemical bead-milling is a promising post-synthetic way to generate nanocrystalline zeotype materials with promoted catalytic performance. Post-milling recrystallization is often entailed to remedy the damaged framework but leads to crystal growth. Herein, using SAPO-34 (ca. 20 µm) derived from inexpensive morpholine as an example, we showcase that secondary growth can be suppressed by porogen-assisted recrystallization, resulting in formation of tiny crystals (100–200 nm) with better mass transport property. The presence of porogen (polydiallyldimethylammonium chloride) also induced a reduction of acid site density owing to a re-distribution of Si across the crystal, which alleviated zoning of Si at the external surface. The catalytic advantages, with respect to a control sample recrystallized in the absence of porogen, have been experimentally verified in dimethyl ether-to-olefin conversion, exhibiting an exaggerated light olefin selectivity and prolonged catalyst lifetime. This advancement of mechanochemical synthesis opens an avenue to better tailor crystal size for zeotype materials.

Computational Study on Production Mechanism of Nano-Graphene Oxide/Poly Diallyl Dimethyl Ammonium Chloride (NGO/PDADMAC) Nanocomposite

Nanographene oxide (NGO) is one of the most attractive carbon nanomaterials, which due to its high surface-to-mass ratio and epoxy functional groups on the plate, carboxy and hydroxy on the edges, is easily dispersed in water and is one of the most effective materials for the surface adsorbent. Poly diallyl dimethyl ammonium chloride (PDADMAC) nanocomposite with nano-graphene oxide (NGO/PDADMAC) is used to treat pollutions of negatively charged colloidal materials in water. To form nano-composite with diallyl dimethyl ammonium chloride monomer in the form of live radical polymerization, are used two intermediates of 2-bromopropyl bromide (BPB) and potassium ethyl xanthate (EX). In this study, nano-graphene oxide is exposed to 2-bromopropionyl bromide (NGO/BPB), is investigated the possibility of interacting with three functional groups (carboxy, hydroxy, and proxy) of the graphene oxide nano-sphere. Potassium ethyl xanthate (EX) and Poly diallyl dimethyl ammonium chloride are then added to their nano-complex (NGO/BPB). Thermodynamic and structural parameters based on B3LYP/6-31 + G** show that the structure of the complex created in the carboxy and hydroxy positions has better structural properties than the epoxy group, with comparing of the groups in the IR spectra of experimental and computational, is more the probability of overlap the hydroxy agent. The thermodynamic, structural, and computational parameters indicate the possibility of forming a composite with the hydroxy agent group to be used as filler.

Preparation of core-shell ZSM-5@Beta molecular sieve and catalytic alkylation to 2,6-Dimethylnaphthalene

ZSM-5@Beta core-shell molecular sieve was prepared by dynamic hydrothermal synthesis method using ZSM-5 adhered Beta seed crystals as the core phase, and polydiallyl dimethyl ammonium chloride (PDDA) was used as a coupling agent to adhere Beta seed crystals on the surface of ZSM-5. The structure and physical properties of composite molecular sieves were characterized by XRD, N2 adsorption-desorption, SEM, TEM, ICP, NH3-TPD and Py-FTIR. The catalytic performance of composite molecular sieves for alkylation of 2-methylnaphthalene (2-MN) with methanol was investigated. The results showed that ZSM-5@Beta composite molecular sieve prepared by this method had a core-shell structure, and the particle size was about 500 nm. Compared with mechanically mixed binary molecular sieve, core-shell molecular sieve had higher specific surface area and external surface area, lower acid strength and stronger acid center density. Through the construction of core-shell interface and hierarchical porous, the catalytic activity was improved by shell phase Beta molecular sieve with 12-membered ring channel, and the catalytic selectivity was improved by core phase ZSM-5 molecular sieve with 10-membered ring channel in the alkylation reaction of 2-MN with methanol. The 2,6-/2,7-DMN ratio in the products reached 1.35, and the yield of 2,6-DMN reached 4.29%.

Effects of poly(diallyldimethylammonium chloride) addition on the curing kinetics of urea-formaldehyde adhesives for particleboards

Addition of poly(diallyldimethylammonium chloride) (PDDA) on the performances of urea-formaldehyde (UF) adhesives was evaluated in this work. Three types of UF adhesives were prepared, one without PDDA addition, and two types with PDDA addition of 1 and 3 wt.% per dry UF adhesive mass. These UF adhesive systems were used for producing experimental particleboard panels. The addition of PDDA decreased the thickness swelling of the panel samples, while the internal bond of the particleboards increased significantly only at the highest PDDA content (3 wt.%). Differential scanning calorimetry (DSC) was applied to address the influence of PDDA on UF adhesive curing kinetics. DSC scans were performed in non-isothermal regimes using different heating rates (5, 10, and 20 ?C?min?1). The activation energy (Ea) of the curing reaction showed slightly lower values for the UF adhesive systems containing PDDA. However, the peak temperatures and enthalpy of reaction did not change significantly. The Kissinger-Akahira-Sunose and Friedman iso-conversional methods were applied to investigate the effects of PDDA addition on the UF adhesive curing process.

An electrochemical sensor based on copper nanowires-PDDA modified glassy carbon electrode for amperometric detection of cysteine in alkaline medium

The development of highly efficient and stable electrocatalysts for their application in electrochemical detection is desirable. Herein, a new copper nanowires (CuNWs) modified electrode was fabricated by coating poly(dimethyl diallyl ammonium chloride) (PDDA) stabilized CuNWs composite onto the the glassy carbon electrode (GCE), and used for electro-catalyze and determination of cysteine (CySH). The morphology, structure, and surface property of fabricated CuNWs were tested using SEM, XRD, and XPS, separately. Electrocatalytic behavior of the modified electrode (CuNWs-PDDA/GCE) for CySH oxidation in alkaline medium was researched by cyclic voltammetry (CV) and chronoamperometry (CA) thoroughly, displaying excellent electrocatalytic oxidation activity and sensing ability towards CySH with a rapid and sensitive anodic current response at low oxidation potential. In the amperometric detection of CySH, the as-prepared electrode displayed a significantly wide linear range from 2 μM to 260 μM and a detection limit of 0.19 μM with a sensitivity of 1.430 μAμM−1cm−2. The proposed CySH sensor exhibited good reproducibility, stability, and anti-interference ability, and has been used to detect CySH in human plasma samples successfully with good applicability.

Bio-inspired non-iridescent structural coloration enabled by self-assembled cellulose nanocrystal composite films with balanced ordered/disordered arrays

Cellulose nanocrystal (CNC) is an interesting polysaccharide nanomaterial that can self-assemble into a chiral nematic liquid crystalline structure in aqueous solution, producing brightly structural color upon selectively reflection of visible light. However, till now, only iridescent structural colors can be created by such colloidal array, making it impossible to be used as colorimetric sensors. Here, inspired by longhorn beetle having short-range ordered but long-range disordered microstructures, it is demonstrated to develop low-/non-angle-dependent structural-color CNC composite films through interference against the long-range orders as a result of introducing positively charged poly (dimethyl diallyl ammonium chloride) (PDDA). By exploring balanced ordered/disordered structures, vivid angle-independent structural colors are realized, enabling accurate cognition for environmental signals, which is crucial to promising applications in sensing, anti-counterfeit, and decoration technology. • Low-/non-angle-dependent structural-color CNC composite films are fabricated. • Balanced ordered/disordered arrays are manipulated by co-assembly with PDDA. • The composite films can be used as colorimetric sensor.

Macro-objects assembly through hydrogen bonding of deoxyguanosine phosphate (dGMP): utilization of polydiallyldimethylammonium chloride and dGMP ionic self-assembly

Macro-objects assembly through hydrogen bonding of deoxyguanosine phosphate (dGMP): utilization of polydiallyldimethylammonium chloride and dGMP ionic self-assembly