Effect of coagulant addition on the sedimentation of a surfactant-containing washing solution used for phenanthrene-contaminated soil

The coagulation of soil particles from a soil-washing solution containing the nonionic surfactant Triton X-100 (TX100) was investigated using various coagulants, such as chitosan (CS), polyacrylamide (PAA), and polyaluminum chloride (PAC). Soil contaminated with phenanthrene (PHE) was washed with aqueous TX100 solutions at concentrations ranging from 0.1 to 20 g/L. The effectiveness of CS (5 mg/L) as a coagulant in the system was compared with PAA (50mg/L) and PAC (50 mg/L), and the results indicated that the system with CS exhibited a more effective separation of soil than those with PAA and PAC. The removal efficiency of PHE (R _j =81.7%) and the selective separation factor (SSF=14.2) at 10 g/L TX100 were the highest for the system with CS (5 mg/L), indicating that the selection of CS as a coagulant in surfactant-mediated soil washing markedly improved both PHE removal and soil separation.     

Novel amphiphilic dextran copolymers nanoparticles for delivery of doxorubicin

In this work, a novel biodegradable amphiphilic copolymer based on dextran and 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphoethanolamine (DPPE) was successfully prepared. The amphiphilic copolymer may self‐assemble into polymeric micelles in an aqueous solution. Fluorescence spectroscopy, dynamic light scattering (DLS), and a transmission electron microscope (TEM) method confirmed the formation of copolymeric micelles. To estimate the feasibility as novel drug carriers, doxorubicin (DOX) was incorporated into polymeric nanoparticles. The DOX‐loaded nanoparticles exhibited greater antitumor effect than free DOX for HeLa celles, suggesting that the dextran/DPPE nanoparticles have great potential as a tumor targeting drug carrier. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Adsorption and fixation behaviour of CI Reactive Red 195 on cotton woven fabric in a nonionic surfactant Triton X‐100 reverse micelle

To achieve the goals of saving water and being salt‐free in the coloration of cotton fabric with reactive dye, nonionic reverse micelles were prepared and optimised with a surfactant, Triton X‐100, n‐octanol and isooctane by injecting a small amount of CI Reactive Red 195 aqueous solution. The adsorption, diffusion and fixation of this dye on cotton fabric in Triton X‐100 reverse micelle and bulk water were then investigated. The equilibrium and kinetic data of the dye adsorption process were evaluated. The colour strength and fixation rate of cotton fabrics dyed in the micelle and in bulk water were also examined and compared. The results indicated that the amount of dye adsorbed increased with the increasing temperature and the initial dye concentration. The dye adsorption process could be described using the Langmuir isotherm and pseudo‐second‐order kinetic equations. It was found that CI Reactive Red 195 showed a stronger adsorption property on cotton fabric in Triton X‐100 reverse micelle than in bulk water without the addition of sodium chloride. Using Triton X‐100 reverse micelle as the dyeing medium offered the reactive dye better diffusion performance within the cotton fibre as compared with bulk water. Moreover, higher fixation of the dyes absorbed on the cotton fibre was achieved when the optimum concentration of sodium carbonate was used as the alkali agent in Triton X‐100 reverse micelle.     

Cloud Point Extraction of Glycyrrhizic Acid from Licorice Root

Abstract

An attempt has been made to extract glycyrrhizic acid (GA) from licorice root by surfactant mediated cloud point extraction (CPE) using non‐ionic surfactant (Triton X‐100). Almost all of the GA molecules were concentrated in the surfactant‐rich phase (also called coacervate phase) after phase separation. The pH is the most critical factor regulating the distribution of GA in the micelle which related to the ionization form. The other effects of the concentration of GA and the surfactant, the temperature, and the salt concentration on the extraction efficiency of GA in the coacervate phase and aqueous phase have been studied. The mechanism of CPE of GA was explored with transmitting electron microscopy. It was deduced that aggregate GA molecules were adsorbed on micelles' outer poler mantle and inner cross‐linked micelles at high GA concentrations in coacervate phase.     

Synthesis of Na+‐montmorillonite/amphiphilic polyurethane nanocomposite via bulk and coalescence emulsion polymerization

Polyurethane/clay nanocomposites have been synthesized using Na⁺‐montmorillonite (Na⁺‐MMT)/amphiphilic urethane precursor (APU) chains that have hydrophilic polyethylene oxide (PEO) chains and hydrophobic segments at the same molecules. Nanocomposites were synthesized through two different crosslinking polymerization methods. One is UV curing of melt mixed APU/Na⁺‐MMT mixtures; the other is coalescence polymerization of APU/Na⁺‐MMT emulsions. These two kinds of composites had intercalated silicate layers of Na⁺‐montmorillonite by insertion of PEO chains in APU chains, which was confirmed by X‐ray diffraction measurement and transmission electron microscopy. These composite films also showed improved mechanical properties compared to pristine APU films. Although the two kinds of nanocomposites exhibited the same degree of intercalation and were synthesized based on the same precursor chains, these nanocomposite films had the different mechanical properties. Nanocomposites synthesized using APU/Na⁺‐MMT emulsions, having microphase‐separated structure, had greater tensile strength than those prepared with melt‐mixed APU/Na⁺‐MMT mixtures. Location of intercalated Na⁺‐MMT by PEO chains at the oil–water interface also could be confirmed by rheological behavior of the APU/Na⁺‐MMT/water mixture. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3130–3136, 2003     

An Odorless,One‐Pot Synthesis of Thioesters from Organic Halides,Thiourea and Benzoyl Chlorides in Water

Thioesterification can be realized via an odorless, one‐pot reaction through the in situ generation of S‐alkylisothiouronium salts from organic halides and thiourea in aqueous Triton X‐100 (TX100) micelles. The protocol is free of foul‐smell thiols and organic solvents, and operates under mild conditions, thereby offering considerable potential for applications in organic synthesis.     

Temperature‐induced surfactant‐ mediated pre‐concentration of uranium assisted by complexation

Cloud‐point extraction (CPE) was used with lipophilic chelating agent to extract uranium(VI) from aqueous solutions. The methodology used is based on the formation of metal complexes soluble in a micellar phase of a non‐ionic surfactant, Triton X‐114. The metal ions complexes are then extracted into the surfactant‐rich phase at a temperature above the cloud‐point temperature. The influence of surfactant concentration on extraction efficiency was studied and the advantage of adding 8‐hydroxyquinoline (8HQ) as lipophilic chelating agent was evidenced. High extraction efficiency was observed, indicating the feasibility of extracting U(VI) using CPE. This study describes a four‐step process—(1) extraction, (2) thermo‐induced phase splitting, (3) back‐extraction and (4) second phase splitting—for the recovery of uranium from water. In our conditions, the extraction yield is quantitative and the concentration factor obtained is superior to 100. After stripping with a diluted nitric acid solution (pH < 1), the system can be recycled through a new four‐step cycle. Copyright © 2006 Society of Chemical Industry     

Polymer micellar aggregates of novel amphiphilic biodegradable graft copolymer composed of poly(aspartic acid) derivatives: Preparation,characterization, and effect of pH on aggregation

Novel amphiphilic biodegradable graft copolymer based on poly(aspartic acid) was prepared by attaching monomethoxy polyethylene glycol (mPEG) as hydrophiphic segment to poly(aspartic acid‐g‐octadecylamine) (PASP‐g‐ODA) as hydrophobic backbone. The chemical structures of amphiphilic copolymers were confirmed by FTIR and ¹H NMR spectroscopy. The polymeric micelles were prepared with solvent evaporation and their physicochemical properties in aqueous media were characterized by dynamic light scattering (DLS) and fluorescence spectroscopy. These micelles were confirmed to be pH‐sensitive by measuring optical transmittance of micelle solution and the size of micellar aggregates. The number average diameter of polymeric micelles prepared in medium at pH 2.5 was larger than that in neutral and basic medium and showed a bimodal size distribution because of the protonation of carboxyl groups in backbone. Furthermore, the polymeric micelle can load water‐insoluble drug (podophyllotoxin), and the drug release from micelles showed a pH‐dependency. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Separation of Neutral Red and Methylene Blue from Wastewater using Two Aqueous Phase Extraction Methods

Abstract

The aim of this work was the two‐aqueous phase extraction of neutral red and methylene blue from wastewater. This has been achieved on the basis of phase separation properties of non‐ionic surfactants above the so‐called cloud point curve and the solubilization phenomena of coacervate micelles (surfactant rich phase). Three commercial surfactants were used in this work; the Oxo‐C₁₅E₇ which is an ethoxylate fatty alcohol (Dehydol LT 7), Triton X‐114 (iso‐C₈H₁₇‐C₆H₄‐(OCH₂CH₂)_7,5OH), and Triton X‐100 (iso‐C₈H₁₇‐C₆H₄‐(OCH₂CH₂)_9,5OH) which are alkyl phenol ethoxylate surfactants. The phase diagrams of binary water/surfactants systems were drawn and the effect of sodium sulphate on water‐surfactant systems was therefore studied. Oxo‐C₁₅E₇ and Triton X‐114 were used for the cloud point extraction of neutral red and methylene blue from their aqueous solutions at 100 mg/L and 7 mg/L, respectively. The experimental extraction results were expressed by the following three responses: percentage of the extracted dye (E), residual concentrations of dye in the dilute phase (X_s,w), and the volume fraction of coacervate (φ_C) at the equilibrium. The results obtained for each parameter were also represented on three‐dimensional diagrams using an empirical smoothing method. The empirical modelling data were in agreement with the experimental ones. The main advantage was sought between E, which has reached 99% in the case of neutral red, whereas in the case of mehtylene blue 92% was obtained with respect to (φ_C), which should have a minimum value. At the optimal conditions, neutral red and methylene blue concentrations in the effluent were reduced to about 500 times and 7 times, respectively.     

Fabrication of thermoresponsive,core‐crosslinked micelles based on poly[N‐isopropyl acrylamide‐co‐3‐(trimethoxysilyl)propylmethacrylate]‐b‐poly{N‐[3‐(dimethylamino)propyl]methacrylamide} for the codelivery of doxorubicin and nucleic acid

Thermoresponsive amphiphilic copolymer, poly[N‐isopropyl acrylamide‐co‐3‐(trimethoxysilyl)propylmethacrylate]‐b‐poly{N‐[3‐(dimethylamino)propyl]methacrylamide} with a branched structure was designed and synthesized by consecutive reversible addition–fragmentation chain‐transfer polymerization. The further hydrolysis of trimethoxysilyl functions in 3‐(trimethoxysilyl) propyl methacrylate units led to the fabrication of core‐crosslinked (CCL) micelles with silica crosslinks at temperatures above the lower critical solution temperature of the poly(N‐isopropyl acrylamide) block. The thermally induced structural and morphological changes of the CCL micelles in aqueous solution were investigated by transmission electron microscopy and ¹H‐NMR analyses. The resulting CCL micelles were further explored as nanocarriers for the codelivery of an anticancer drug and nucleic acid for enhanced therapeutic efficacy. The CCL micelles effectively condensed the nucleic acid and mediated higher gene transfer in the presence of serum than in serum‐free transduction. A cytotoxicity study revealed that whereas the pure CCL micelles exhibited unapparent cytotoxicity, the codelivery of p53 and doxorubicin with the CCL micelle formulation resulted in better treatment efficiency than sole chemotherapy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41752.     

Effect of surfactants on phenol removal by the method of polymerization and precipitation catalysed by Coprinus cinereus peroxidase

The removal of phenol by peroxidase‐catalysed polymerization was examined using Coprinus cinereus peroxidase in the presence of surfactants. The non‐ionic surfactants with poly(oxyethene) residues, Triton X‐100, Triton X‐405 and Tween 20, enhanced the phenol removal efficiency at a level similar to high relative molecular mass poly(ethylene glycol) (relative molecular mass 3000). Although the improvement in the removal efficiency was less than that of Triton X‐100, Span 20, sodium lauryl sulfate (SDS) and lauryl trimethylammonium bromide (DTAB) also enhanced the removal efficiency. The requirement of the enzyme for almost 100% removal of 100 mg dm^?3 phenol decreased to one‐fourth by the addition of 30 mg dm^?3 Triton X‐100. Triton X‐100, Triton X‐405, Tween 20 and DTAB could reactivate the enzyme precipitated with the phenol polymer, leading to the restarting of the phenol removal reaction. Copyright © 2003 Society of Chemical Industry     

Synthesis and characterization of PEG–PCL–PEG triblock copolymers as carriers of doxorubicin for the treatment of breast cancer

Triblock copolymers of monomethoxy poly(ethylene glycol) (mPEG) and ε‐caprolactone (CL) were prepared with varying lengths of poly(ε‐caprolactone) (PCL) compositions and a fixed length of mPEG segment. The molecular characteristics of triblock copolymers were characterized by ¹H NMR, gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and differential scanning calorimetry (DSC). These amphiphilic linear copolymers based on PCL hydrophobic chain and hydrophilic mPEG ending, which can self‐assemble into nanoscopic micelles with their hydrophobic cores, encapsulated doxorubicin (DOX) in an aqueous solution. The particle size of prepared micelles was around 40–92 nm. The DOX loading content and DOX loading efficiency were from 3.7–7.4% to 26–49%, respectively. DOX‐released profile was pH‐dependent and faster at pH 5.4 than pH 7.4. Additionally, the cytotoxicity of DOX‐loaded micelles was found to be similar with free DOX in drug‐resistant cells (MCF‐7/adr). The great amounts of DOX and fast uptake accumulated into the MCF‐7/adr cells from DOX‐loaded micelles suggest a potential application in cancer chemotherapy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Nonionic surfactants induced cloud point extraction of Polyhydroxyalkanoate from Cupriavidus necator

Polyhydroxyalkanoate synthesized by Cupriavidus necator DSM 428 was purified from the crude fermentation broth as such by performing nonionic surfactants (Triton X100, Triton X114 & Tergitol 6) induced cloud point extraction. Polyhydroxyalkanoate was extracted into the micelle-rich bottom phase (coacervate phase), while most of the cellular impurities partitioned into the aqueous phase. Cloud point temperatures and the extraction efficiency of different cloud point systems were studied at different pH value and in the presence of additives. Maximum extraction of biopolymer was achieved (recovery of 84.4%) with a purity of 92.49% at 3 pH with the addition of 0.1 M ammonium chloride in the mixed surfactant system at a reduced cloud point temperature of 33°C.     

Enhanced sorption of phenanthrene on activated carbon in surfactant solution

Distribution of a hazardous hydrophobic organic compound (HOC) and a nonionic surfactant in aqueous/activated carbon systems was investigated. Phenanthrene was selected as a representative HOC and Triton X-100 as a surfactant. Three activated carbons that differed in size (Darco 20-40, 12-20 and 4-12 mesh sizes) were used in the adsorption experiments. The system was analyzed using a mathematical partitioning model and compared with intrinsic sorption of phenanthrene without the effect of sorbed surfactant. Phenanthrene was sorbed onto activated carbon in a greater amount than an estimated value by intrinsic sorption, even though surfactant molecules covered most of surfaces. The sorbed surfactant was much more effective as a sorbent for phenanthrene, in the range of 1.2-98 for effectiveness factor, than was activated carbon, particularly at high surfactant doses. We introduced surface molar solubilization ratio (MSR_s) for sorbed micelles of surfactant and mathematically estimated using effectiveness factor and available carbon fraction of activated carbon after surfactant sorption. The MSR_s for sorbed surfactant was 5-46 times higher than the MSR for micellar surfactant in bulk solution. The sorbed surfactant onto activated carbon can more effectively remove hazardous organic compounds in liquid environmental samples.     

Use of Micellar Solutions as Draw Agents in Forward Osmosis

Recent advances in membrane technologies have enhanced the viability of water treatment strategies that employ semipermeable barriers. Forward osmosis (FO), which exploits the natural osmotic pressure gradient between a “draw” solution and a “feed” solution to produce potable water, offers a low‐energy, low‐cost alternative to more conventional treatment methods. Surfactants, because of their tendencies to aggregate into micelles and to adsorb at interfaces, provide intriguing osmotic pressures and offer exploitable properties by which draw solutions can be regenerated. The effectiveness of surfactant‐based FO using cellulose triacetate membranes has been assessed in terms of water flux and reverse surfactant diffusion using cetylpyridinium chloride, sodium dodecylsulfate, and Triton X‐100. The ratios of water flux to surfactant flux exceeded 600 L mol^?1 for all surfactants studied. Surfactant recoveries of over 99 % were achieved by ultrafiltration using regenerated cellulose membranes.     

Synthesis and micelle behavior of (PNIPAm-PtBA-PNIPAm)m amphiphilic multiblock copolymer

A linear amphiphilic multiblock copolymer (PNIPAm-PtBA-PNIPAm)_m was successfully synthesized by a two-step reversible addition-fragmentation transfer (RAFT) polymerization in the presence of a cyclic trithiocarbonate as RAFT agent. The micelle behavior of (PNIPAm-PtBA-PNIPAm)_m multiblock copolymer in aqueous solution was then investigated by means of normal TEM, cryo-TEM, static and dynamic light scattering. The morphology, size, and size distribution of (PNIPAm-PtBA-PNIPAm)_m micelles were found to be dependent on the initial concentration of multiblock copolymer in THF. Spherical micelles, associated aggregates of spherical micelles, cage-like micelles, layered structures, and vesicular micelles were experimentally observed, which were in good agreement with the prediction of theory and simulations on linear amphiphilic multiblock copolymer in selective solvent. The (PNIPAm-PtBA-PNIPAm)_m micelles also exhibit thermo-sensitive behavior in aqueous solution because of the PNIPAm blocks.     

Cationic amphiphilic copolymers: synthesis,characterization, self‐assembly and drug‐loading capacity

Amphiphilic copolymers with cationic hydrophilic moieties and different ratios of hydrophobic portion to hydrophilic portion were designed and synthesized via the combination of hydrosilylation reactions and quaternization reactions. The structures were characterized through Fourier transform infrared spectroscopy, ¹H NMR , ¹³C NMR and gel permeation chromatography. The measurements of critical micelle concentrations, electrical conductivities and zeta potentials indicated that the copolymers could self‐assemble into nanoparticles with charges around the surface in aqueous solution. The sizes of the micelles were between 67 nm and 104 nm detected by dynamic light scattering. The self‐assembled micelles were used as drug carriers to encapsulate a model drug (tocopherol), and their drug‐loading content (DLC ) and efficiency (DLE ) were determined by UV ?visible spectra, resulting in considerable drug‐loading capacity to a tocopherol maximum up to 17.2% (DLC ) and 80.3% (DLE ) with a size of 90 nm. The blank micelles and drug‐loaded micelles displayed a spherical shape detected by transmission electron microscopy, which demonstrated not only the self‐assembly behaviors but also the drug‐loading performances of the cationic amphiphilic copolymers. All the results demonstrated that the cationic amphiphilic copolymers could be used as potential electric‐responsive drug carriers. © 2017 Society of Chemical Industry     

A novel thermosensitive triblock copolymer from 100% renewably sourced poly(trimethylene ether) glycol

Bio‐based amphiphilic triblock copolymers with 100% renewably sourced poly(trimethylene ether) glycol (PO3G) as the hydrophobic blocks and statistical copolymer of 2‐(2‐methoxyethoxy)ethyl methacrylate (MEO₂MA) and oligo(ethylene glycol)methacrylate (OEGMA) [P(MEO₂MA‐stat‐OEGMA)] as the hydrophilic blocks are synthesized and characterized. It is found that the molar ratio of MEO₂MA/OEGMA among the resulting copolymers is approximately 70/30. The degree of polymerization (DP) of P(MEO₂MA‐stat‐OEGMA) block ranges from 16 to 90, and the DP of PO3G block is fixed at 35. The amphiphilic copolymers could form core‐shell micelles self‐assembly in aqueous solution at low concentrations, and the micelles are in spherical shape with sizes varying from 121 to 188 nm. With the increasing length of hydrophilic blocks, the critical micelle concentration increases from 2.15 to 13.8 mg L^?1, and the lower critical solution temperature improves from 32.5 to 38.4 °C. The in vitro doxorubicin (DOX) release study shows that all DOX‐loaded micelles have a higher release rate at 37 °C than that at 25 °C. Cytotoxicity test reveals that the blank micelles are nearly nontoxic. These results indicate that the block copolymer micelles containing 100% renewably sourced PO3G can serve as a potential drug delivery carrier. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46112.     

Synthesis of amphiphilic temperature‐sensitive poly(N‐isopropylacrylamide)‐block‐poly(tetramethylene carbonate) block copolymers and micellar characterization

Amphiphilic thermally sensitive poly(N‐isopropylacrylamide)‐block‐poly(tetramethylene carbonate) block copolymers were synthesized by ring‐opening polymerization of tetramethylene carbonate with hydroxyl‐terminated poly(N‐isopropylacrylamide) (PNiPAAm) as macro‐initiator in the presence of stannous octoate as catalyst. The synthesis involved PNiPAAm bearing a single terminal hydroxyl group prepared by telomerization using 2‐hydroxyethanethiol as a chain‐transfer agent. The copolymers were characterized using ¹H NMR and Fourier transform infrared spectroscopy and gel permeation chromatography. Their solutions show reversible changes in optical properties: transparent below the lower critical solution temperature (LCST) and opaque above the LCST. The LCST depends on the polymer composition and the media. Owing to their amphiphilic characteristics, the block copolymers form micelles in the aqueous phase with critical micelle concentrations (CMCs) in the range 1.11–22.9 mg L^?1. Increasing the hydrophobic segment length or decreasing the hydrophilic segment length in the amphiphilic diblock copolymers produces lower CMCs. A core‐shell structure of the micelles is evident from ¹H NMR analyses of the micelles in D₂O. Transmission electron microscopic analyses of micelle morphology show a spherical structure of both blank and drug‐loaded micelles. The blank and drug‐loaded micelles have an average size of less than 130 nm. Observations show high drug‐entrapment efficiency and drug‐loading content for the drug‐loaded micelles. Copyright © 2010 Society of Chemical Industry     

Synthesis and morphology transformation of amphiphilic diblock polyurethane copolymers in aqueous solution

Amphiphilic block copolymers possess both hydrophobic and hydrophilic properties and can form versatile micellar structures in aqueous solution. The aim of the research presented was to prepare a series of non‐ionic amphiphilic diblock polyurethane copolymers (PUn) based on isophorone diisocyanate, monoallyl‐end‐capped poly(ethylene oxide) and poly(propylene oxide) (PPO), followed by an investigation of their micellization properties and morphology transformation in aqueous solution. The PUn samples were synthesized by condensation polymerization. These polyurethanes exhibit surface tension as low as 33.7–37.0 mN m^?1. There is an obvious decrease in critical micelle concentration as the hydrophobic PPO molecular weight increases. According to transmission electron microscopy, the morphology of aggregates of the copolymers can be tuned by varying the concentration in aqueous solution rather than organic solvent. For example, for PU7, large compound micelles are produced instead of vesicles. For PU17, the concentration can be used to control the size and thickness of vesicles. Vesicle size increases from 60 to 500 nm and vesicle thickness from 40 to 60 nm with concentration ranging from 0.003 to 0.03 wt%. The study shows that the copolymers in aqueous solution have excellent surface activities. In addition, they can self‐assemble into large compound micelles or vesicles at certain concentrations. Moreover, the synthesis method described allows one to obtain a desired morphology of aggregates by adjusting the composition of hydrophilic and hydrophobic segments, which provides a novel and simple way to obtain particles on the nanometer scale. Copyright © 2010 Society of Chemical Industry