EO Chain Research Articles

Self‐Healing and Flexible Ionic Gel Polymer Electrolyte Based on Reversible Bond for High‐Performance Lithium Metal Batteries

The low ionic conductivity, poor interface contact, and low safety of the electrolytes are the main problems in the practical application in flexible lithium metal batteries. A new type of chemical crosslinked ionic gel polymer electrolyte (IGPE) with good self‐healing ability and excellent electrochemical properties is designed based on polyoxyethylenebis(amine), and 1,3,5‐benzenetricarboxaldehyde in the presence of ionic liquid through a one‐step reaction. The interaction between ionic liquid and polymer with the ether oxygen atom of EO chains improves the stability of IGPE and the crystallinity decreased significantly due to the incorporation of ionic liquid. The IGPEs show good self‐healing, film flexibility, and high ionic conductivity even at −25 °C. They also possess high thermal stability, wide electrochemical stability window, and good interfacial compatibility. The Li/IGPE‐50/LiFeO4 battery with IGPE‐50 as an electrolyte is studied and the high discharge capacity of 154.8 mAh g−1 is obtained at 0.1 C with 99.6% of coulombic efficiency, and remains 132.8 mAh g−1 on the 50th cycle. Ionic liquid combined with polymers based on dynamic reversible bonds can optimize the electrochemical performance of IGPEs, and improve its safety and stability, which is very useful for flexible lithium metal batteries.

Impact of EO chain length of dodecanol ethoxylates (C12En) on the rheological properties and physical stability of pesticide suspension concentrate

Rheological measurement can provide not only the shear-induced but also strain-induced microstructural changes, as well as transient network formation and subsequent recovery with time. It has been explored as a useful tool for probing the interparticle interactions which govern the physical stability of concentrated suspension. However, its application in pesticide formulation is rarely investigated. Herein, the rheological properties of 25% mancozeb suspension concentrate stabilized with nonionic surfactants dodecanol ethoxylates (C12En, n = 3, 7, 9, 15, 20) were studied. The steady-state shear measurement showed that all the 25% mancozeb suspension concentrate displayed shear-thinning flow. The experimental flow behavior followed prediction of Herschel–Bulkley model with the correlation coefficients greater than 0.99. Oscillatory shear measurements showed the viscoelastic response of 25% mancozeb suspension concentrate transformed from solid-like to gel-like viscoelasticity with the addition of C12En. As the EO chain length of C12En increased, the apparent viscosity and elastic modulus decreased initially, followed by an increase behavior. The thixotropic response of mancozeb formulations was evaluated by applying a three-step test. It turned out that the addition of C12En changed the mancozeb suspension concentrate from normal viscoelastic fluid to inelastic thixotropic material, and the recovery of viscosity gradually decreased as the EO chain length increased. Besides, the influence of C12En on suspension rate and particle size of 25% mancozeb suspension concentrate was investigated. The results showed that C12E9 performed best in improving the physical stability of the formulations before and after thermal storage. From SEM imagines of mancozeb particles, it was found that the aggregation was inhibited by C12E9, which was also responsible for the best dispersibility, minimum apparent viscosity and elastic modulus of 25% mancozeb suspension concentrate with the addition of C12E9.

Synthesis and properties of the active polymer for enhanced heavy oil recovery

With the continued recovery of heavy oil, conventional polymer flooding cannot be applied to heavy oil reservoirs gradually due to the characteristics of heavy oil reservoirs. To study oil displacement agent suitable for enhanced heavy oil recovery and investigate the effect of EO chain length on the performances, acrylamide, acrylic acid, lauryl methacrylate and C 10 -C 16 alkylphenol ethoxylates were selected to co-polymerize into the active polymer PAAP-x with different EO chain length (14, 16, 18, 20 and 22). Proton nuclear magnetic resonance analysis indicated PAAP-x as the target product. The optimal EO chain length of PAAP-x was determined to be 18 by the analysis of thickening, salt-tolerance, interfacial activity, wettability, viscosity reduction and recovery. Compared with conventional polymer P1, 1500 mg/L PAAP-18 exhibited superior performances with salinity of 6882.2 mg/L: (1) PAAP-18 could maintain the viscosity of 113.1 mPa . s, while P1was 44.8 mPa . s. (2) PAAP-18 could reduce the water-oil IFT from 44.4 mN/m to 13.0 mN/m, while P1 was to 30.6 mN/m, and the water-oil contact angle was 58.2°and 108.5°, respectively. (3) The heavy oil viscosity reduction rate of PAAP-18 was 81.7% at 50 °C, while P1 was only 33.8%. (4) PAAP-18 enhanced heavy oil recovery by 19.85% on the basis of water flooding while conventional polymer was only 8.69%. This study has theoretical guidance and practical significance for the study on new oil displacement agent to enhance heavy oil recovery. • Active polymer PAAP with optimal EO chain length of 18 were successfully synthesized. • PAAP-18 was better than conventional polymer in performances. • PAAP-18 could enhance heavy oil recovery by 19.85% on the basis of water flooding. • PAAP-18 simultaneously improve the oil displacement efficiency and the sweep efficiency.

Effects of oxyethylene groups on the adsorption behavior and application performance of long alkyl chain phosphate surfactants

Alcohol ether-derived surfactants have caused extensive research in the past period. Alcohol ether phosphate is one of them. However, detailed information about long alkyl chain phosphates (LAPs) is rarely reported in the previous literature. To bridge this gap, in this paper, LAPs with different oxyethylene (EO) addition numbers are used as the research objects. The influence of EO chain length on the adsorption behavior of LAPs is explored through static surface tension, dynamic surface tension and dynamic contact angle. The results indicate that the LAPs that contain no EO group or with fewer EO groups have very low surface tension reduction efficiency and kinetic surface activity, but it can be significantly improved by introducing longer EO chains. The adsorption process of LAP samples with faster adsorption rate on the gas-liquid surface is the mixed diffusion-kinetic mechanism. It has the fastest adsorption rate when the EO addition number is 9. In addition, the wetting, permeability, emulsification, and foam stability of LAPs can be significantly improved by introducing a longer EO chain, but the antistatic property is better when the EO chain is shorter.

Controlling impact behavior on superhydrophobic surfaces for droplets of nonionic surfactants by tailoring hydrophilic chain length

The behavior of high-speed droplets impacting on superhydrophobic surfaces plays an essential role in many daily applications. Adding surfactants is one excellent approach to improve droplet retention through enhancing the solid-liquid interface interaction. However, the regulating of the impact process has been rarely concerned about the effect of molecular structure on it. In our work, we study the impact behavior of nonionic surfactants Triton X (TX) on superhydrophobic surfaces by characterizing the diffusion rate of surfactant molecules and the receding contact angle and adhesion of surfactant solution on surfaces. We reveal that droplets of TX surfactant solution can deposit better on superhydrophobic surfaces as hydrophilic (ethylene oxide, EO) chain length increasing, which is mainly attributed by the faster diffusion speed towards the newly formed interface during the spreading phase, leading to better wettability transition and larger pinning area on the substrate. Our work promotes the understanding of the mechanism that controls the impact behavior of droplets of surfactant by adjusting the EO chain length, which provides an effective strategy to control droplet deposition on superhydrophobic surfaces.

Nonionic surfactant stabilized polytetrafluoroethylene dispersion: Effect of molecular structure and topology

Polytetrafluoroethylene (PTFE) is a kind of fluoropolymer with many critical applications. Nonionic surfactant stabilized concentrated PTFE aqueous dispersions are widely used to prepare corresponding products via dipping, spraying, spinning, or film casting, as these surfactants exert a negligible effect on the properties of the products. Although many nonionic surfactants have been used to stabilize PTFE dispersions in industry, the effects of molecular structure and topology are not well-documented; thus, currently, there is no basis for selecting or designing suitable novel surfactants to enhance dispersion stability. In this work, five nonionic surfactants with different topological structures including Tween 20, Tween 60, Tween 80, Brij L23, and Brij O20, were used to prepare concentrated PTFE dispersions. The variation of particle morphology before and after concentration was examined by scanning electron microscopy, and the static stability of the dispersions was quantitatively and objectively characterized using a Turbiscan analyzer based on multiple light scattering. Then the effect of surfactant molecular structure and topology on dispersion stability was discussed. We found that, after the enrichment process, the PTFE microspheres were tightly packed, and some were deformed. Brij surfactants which bears a linear hydrophilic oxyethylene (EO) chain can form a thicker hydration layer on the surface of PTFE particles than those of Tween surfactants which contains a branched hydrophilic EO chain. Accordingly, PTFE dispersions with Brij surfactants show better static stability. Moreover, in comparison with the saturated hydrophobic tail, the unsaturated hydrophobic chain is more flexible, so it can adhere to the surface of PTFE particles better, improving the stability. In addition, the increase of surfactant concentration contributes to the increase of micelles density and viscosity of the bulk dispersion, which can also enhance the stability. These findings are beneficial to design or choose suitable surfactants for high stability and high-quality concentrated PTFE dispersions.

Solubilization of fullerene in polyoxyethylene tetradecyl ether type nonionic surfactants

Fullerene is insoluble in water owing to its bulky spherical structure composed of 60 carbons. Herein, polyoxyethylene tetradecyl ether-type nonionic surfactants with a varying number of oxyethylene groups, i.e., C14En (n = 5, 6, and 7), were used to solubilize fullerene. In addition, a solubilization experiment was conducted using the aromatic compound naphthalene as a reference substance. Fullerene tended to solubilize in aqueous solutions of surfactants bearing long EO chains. Particularly, the maximum solubilization quantities of fullerene increased with an increasing number of EO chains in 100 mmol L−1 C14En solutions ranging from 43.2 (n = 5) to 76.9 (n = 6) and 115.6 μmol L−1 (n = 7). In contrast, naphthalene was well solubilized in surfactants bearing relatively shorter EO chains and showing an opposite tendency to that of fullerene. The Gibbs free energy change (ΔG0) per EO chain for the solubilization of fullerene and naphthalene was –1.51 and +0.27 kJ mol−1, respectively. These results indicated that the extension of EO chain of nonionic surfactants is thermodynamically advantageous for achieving the solubilization of fullerene. In addition, the solubilization site of fullerene in the micelles was studied by analyzing its absorption spectrum in four types of solvents with different polarities. The peak wavelength of fullerene suggested that the surrounding environment possessed an intermediate polarity between water and organic solvents. According to the 1H NMR measurements, the waveform of the EO groups in the NMR spectra significantly split upon solubilization of fullerene. From these results, it was concluded that fullerene located in the vicinity of the EO chains (shell area) in the micelles.

Surface Adsorption and Bulk Properties of Surfactants in Quaternary-Ammonium-Salt-Type Amphiphilic Monomeric and Gemini Ionic Liquids.

The physicochemical properties of ionic liquids can be readily controlled. Currently, it is necessary to investigate the properties of different surfactants to elucidate the mixtures used in quaternary-ammonium-salt-type ionic liquids. Herein, the surface adsorption and bulk properties of homogeneous polyoxyethylene (EO)-type nonionic surfactant, quaternary-ammonium-salt-type cationic surfactant, and sulfobetaine-type zwitterionic surfactant are elucidated in quaternary-ammonium-salt-type amphiphilic monomeric ionic liquids and gemini ionic liquids with bis(fluorosulfonyl)imide or bis(trifluoromethanesulfonyl)imide as counterions. The monomeric amphiphilic ionic liquids that adsorbed at the interface were replaced with CxEOy (where x and y represent alkyl and EO chain lengths, respectively) as the concentration of CxEOy increased. On the other hand, in the gemini amphiphilic ionic liquids, the surface tensions of CxEOy were lower than those of the monomeric ionic liquids. Consequently, both gemini amphiphilic ionic liquids and CxEOy adsorbed efficiently at the interface and oriented themselves because of a synergistic effect. Furthermore, for ionic liquids with short alkyl chains, an orderly bulk nanostructure was not observed at low concentrations in CxEOy, while a layer structure formed at higher concentrations; in contrast, ionic liquids with long alkyl chains formed a layer structure. The alkyl chains, which were interlocked in the bilayer structure, resulted in a densely packed layer structure.

Precise control of cyclodextrin-based pseudo-polyrotaxane lamellar structure via axis polymer composition.

Self-assembly of cyclodextrin (CD) with guest polymers has attracted much attention owing to its biocompatibility and accessibility. In this study, we investigate the composition effect of poly(ethylene oxide)m-b-poly(propylene oxide)n-b-poly(ethylene oxide)m (EOmPOnEOm) triblock copolymers on lamellar or plate structures formed by complexation with β-CD. EO5PO29EO5, EO14PO29EO14, and EO75PO29EO75 show periodic lamellar morphology consisting of single-crystalline pseudo-polyrotaxane (PPR) nanosheets with a thickness equal to the central PO length. This is because β-CDs selectively cover the PO component and cause the microphase separation between β-CD and EO layers. The thickness of the EO layers increases linearly with increasing number of EO units, which suggests that the EO chains are constrained into virtual cylinders with the diameter of the β-CD. This means that we can precisely control the thickness of both the crystal (β-CD and PO) and the amorphous (EO) layers in the lamellar structure. In contrast, EO2PO29EO2 forms a thin plate structure, where not only PO but also EO chains are covered with β-CD. Furthermore, the length of the central PO component is necessary to form the lamellar structure with the phase separation between the β-CD and EO layers. These findings provide a more fundamental understanding to enhance the variety and applicability of CD-based self-assembled materials.

Adsorption and aggregation properties of alkoxy-group-modified homogeneous polyoxyethylene alkyl ether nonionic surfactants

The development of new surfactants with interesting properties and new functionalities that can be controlled in a simple manner is an important industrial objective. Herein, we report the synthesis of homogeneous polyoxyethylene (EO) alkyl ether nonionic surfactants modified with alkoxy groups (C12EO8OR, where C12 and EO8 are dodecyl and octaoxyethylene chains, respectively, and R = Me and Et) from a homogeneous EO-type hexaoxyethylene dodecyl ether (C12EO6) and diethylene glycol monomethyl ether or diethylene glycol monoethyl ether. The adsorption and aggregation properties of these surfactants were characterized through cloud point and surface tension measurements, and by small-angle X-ray scattering, polarization microscopy, and cryogenic transmission electron microscopy; these properties were compared to those of previously reported homogeneous EO-type (C12EO8) and polyoxypropylene-polyoxyethylene type surfactants (C12EO8POy, y = 1, 2, 3). The introduction of a methoxy or ethoxy group at the terminus of the EO chain in C12EO8 resulted in an increase in hydrophobicity and a greatly reduced cloud point. Substitution of the terminal hydroxy group of the EO chain in C12EO8 with methoxy and then ethoxy led to increasingly lower surface tensions in solution and more efficient air/water interfacial adsorption. C12EO8OR formed small micelles at low concentrations in solution, and the micelles of C12EO8OMe transformed to hexagonal liquid crystals with increasing surfactant concentration, whereas C12EO8OEt remained to form micelles even at high concentration; that is, the introduction of bulkier functional groups into the C12EO8 surfactant helps to control the formation of aggregates with higher-order structures.

A comparative study on the effect of structural variations of co-solvent on the Tetronic® micelles with widely different hydrophobicity

Here we report, a comparative study on the micellization and phase behavior of two commercially available ethylene oxide – propylene oxide (EO-PO) octablock copolymers, Tetronics® 1304 and 1307 (hereafter written as T1304 and T1307), in the presence of 2,2,2‑trifluoroethanol (TFE) and ethanol (EtOH) using cloud point (CP), dynamic light scattering (DLS), high sensitivity differential scanning calorimetry (HSDSC), relative viscosity and Langmuir film balance. These copolymers fabricated with almost the same PO block length vary in their EO chain lengths and hence display different characteristics. T1304 shows a more hydrophobic character and forms micelles at ambient temperature while T1307, due to longer EO chain length, exhibits high hydrophilicity and faces difficulty in forming micelles which results into high polydispersity in the aqueous system. In the presence of co-solvents TFE and EtOH, however a more interesting behavior is noted. T1304, as evident from DLS and viscosity measurements, displays micellar growth in the presence of TFE, while the presence of EtOH induces micellar breakdown. Though, in case of T1307, presence of TFE improves micellization and a single micellar peak becomes evident in the DLS stacks, no micellar growth can be noticed both through DLS and relative viscosity, which is possibly due to its highly hydrophilic character. Likewise, presence of TFE depresses the CMT in both the copolymers while EtOH increases it. A similar trend is also justified by π-A isotherms form Langmuir monolayers.

Emulsification, solubilization, and detergency behaviors of homogeneous polyoxypropylene-polyoxyethylene alkyl ether type nonionic surfactants

The emulsification and solubilization properties and detergency behaviors were investigated using homogeneous polyoxypropylene-polyoxyethylene (PO-EO) alkyl ether type nonionic surfactants (C12EOxPO3, where x represents EO chain lengths of 6 and 8, and C12 and PO3 indicate the dodecyl chain and single trioxypropylene chain, respectively) and polyoxyethylene (EO) alkyl ether type nonionic surfactants (C12EOx, x = 6 and 8). These nonionic surfactants possess single EO and PO chain lengths without a distribution. An oil-in-water (O/W) type emulsion prepared using mixtures of nonionic surfactant C12EOxPO3 or C12EOx solutions and squalane was shown to be stable in the order of C12EO6PO3 << C12EO6 < C12EO8PO3 < C12EO8. The introduction of a PO chain to the terminal hydroxy group of the EO chain lowers the emulsion stability owing to the difficult orientation of a complex structure such as the hydrophobic alkyl chain–hydrophilic EO chain-hydrophobic PO chain at the water/oil interface. The solubilization of these nonionic surfactants was shown to be higher for stearic acid than for naphthalene as a solubilizate. The molar solubilization ratio (MSR) for naphthalene and stearic acid was the highest for C12EO6PO3 and C12EO8PO3, respectively. The removal of stearic acid from a gold substrate evaluated using a quartz crystal microbalance (detergency) was the highest for C12EO6PO3 among the four surfactants applied. Thus, no significant correlation was found among the emulsification, solubilization, and detergency behaviors ; however, a high performance for each objective was obtained by controlling both the EO chain length and the introduction of a PO chain.

Dilational rheological properites of oxyethylated fatty acid methyl esters at kerosene-water interface

Dilational rheological properties of oxyethylated fatty acid methyl esters (FMEEs) with different structure (C12E5、C14E5、C16E5 and C18=E5) at kerosene-water interface have been investigated as a function of time, frequency and bulk concentration by the oscillating drop method. The experimental results show that the dilational modulus increases with an increase in the alkyl chain length for FMEEs with saturated alkyl chains (C12E5、C14E5 and C16E5) due to the enhanced hydrophobic interaction among the molecules at interface and the slowed diffusion-exchange process. At the same time, the phase angles are relative low, which embodies characteristics of nonionic surfactants containing EO chain. As for C18=E5, the introduction of a double bone causes a decrease in the dilational modulus and a slight increase in the phase angle, as evidenced by an increase in the value of the slope of curve, because the flexible unsaturated alkyl chain enhances the diffusion-exchange process. Moreover, the modulus vs interfacial pressure curve passes through a maximum during higher interfacial pressure range for C18=E5, which indicates that the interfacial rearrangement process affects the nature of adsorption layer.

Interfacial dilational rheology of fatty acid methyl ester and alkyl benzene sulfonate mixed solutions

The dilational rheological properties of aqueous solutions of anionic surfactant sodium 3,4-diheptylbenzene sulfonate (C7C7phS), nonionic surfactant oxyethylated fatty acid methyl esters (C18=E10) and their mixtures have been investigated at the kerosene-water interface by the oscillating drop method. The influences of time, dilational frequency, bulk concentration and interfacial pressure on the dilational properties have been expounded. The experimental results show that the in-film process, such as the orientation change of EO chain, controls the properties of adsorption layers formed by nonionic surfactant C18=E10 molecules. On the other hand, the diffusion-exchange process plays the crucial roles in determining the nature of film containing anionic surfactant C7C7phS molecules. The dilational rheological behaviors of C18=E10/C7C7phS mixtures in the presence of 1 × 10−5 mol·L−1 C7C7phS are close to those of C18=E10. At the same time, mixtures at mole ratio 1:1 show similar behaviors with C7C7phS. The mixed adsorption of C18=E10 and C7C7phS may lead to more compact films and result in higher interfacial elasticity.

The ultra-low interfacial tension behavior of the combined cationic/anionic-nonionic gemini surfactants system for chemical flooding

Gemini surfactants have attracted intensive attention owning to their unique physical and chemical properties and have gradually been applied in the field of enhanced oil recovery (EOR). In this work, a combined cationic/anionic-nonionic gemini surfactant system consisting of cetyltrimethyl ammonium bromide (CTAB) and anionic-nonionic gemini surfactants (GAES-9) was proposed for EOR. The surface performance of the combined system was superior to that of either surfactant alone. Critical micelle concentration (CMC) data were used to calculate the molecular interaction parameters according to the regular solution theory. The combined CTAB/GAES-9 surfactant system could greatly affect the interfacial tension (IFT) between water and crude oil, and the strength of this effect depended on the mole fraction and concentration of CTAB/GAES-9. The system could reduce the IFT to an ultra-low level at a total concentration of 200 mg/L, and the system could still maintain ultra-low IFT at a salinity of 10 × 104 mg/L. The mechanism underlying the synergistic effect of CTAB/GAES-9 to obtain ultra-low IFT was systematically investigated. It is most probably related to a large number of anions and cations being adsorbed onto the oil-water interface due to electrostatic attraction. Meanwhile, the spatial structure of the elongated, flexible EO chains in the gemini surfactant entangled at the oil-water interface shields some CTAB cations, enabling the adsorption of more cations. To summarize, the combined surfactants exhibit remarkable abilities and could serve as a candidate for EOR in harsh reservoirs.

Cross-Linked Nanohybrid Polymer Electrolytes With POSS Cross-Linker for Solid-State Lithium Ion Batteries.

A new class of freestanding cross-linked hybrid polymer electrolytes (HPEs) with POSS as the cross-linker was prepared by a one-step free radical polymerization reaction. Octavinyl octasilsesquioxane (OV-POSS) with eight functional corner groups was used to provide cross-linking sites for the connection of polymer segments and the required mechanical strength to separate the cathode and anode. The unique cross-linked structure offers additional free volume for the motion of EO chains and provides fast and continuously interconnected ion-conducting channels along the nanoparticles/polymer matrix interface. The HPE exhibits the highest ionic conductivity of 1.39 × 10−3 S cm−1, as well as excellent interfacial compatibility with the Li electrode at 80°C. In particular, LiFePO4/Li cells based on the HPE deliver good rate capability and long-term cycling performance with an initial discharge capacity of 152.1 mAh g−1 and a capacity retention ratio of 88% after 150 cycles with a current density of 0.5 C at 80°C, demonstrating great potential application in high-performance LIBs at elevated temperatures.

Adsorption dynamics of homogeneous polyoxypropylene-polyoxyethylene alkyl ether nonionic surfactants at the air/water interface

The dynamic surface tensions of two homogeneous polyoxyethylene (EO) alkyl ether nonionic surfactants with terminal hydroxy group (C12EOx, where C12 is a dodecyl chain and x is the length of the EO chain; x = 6, 8) and two homogeneous polyoxypropylene-polyoxyethylene (PO-EO) alkyl ether nonionic surfactants (C12EOxPO3, where PO3 is a trioxypropylene chain inserted between the EOx and the terminal hydroxy group) were measured using the maximum bubble pressure method. The effects of EO chain length, the presence or absence of the PO3 chain, and the surfactant concentration on the maximum rates of surface-tension reduction and diffusion coefficient were investigated. The C12EO6PO3 surfactant exhibited the fastest rate of surface-tension reduction of the four systems studied, despite its complex hydrophobic-alkyl-chain/hydrophilic-EO-chain/hydrophobic-PO-chain structure that differs from that of conventional EO alkyl ether surfactants. The diffusion coefficients obtained from short and long time analyses indicate that surfactant diffusion to the subsurface is faster for the C12EOxPO3 surfactants than the C12EOx surfactants (short time data), while surfactant adsorption from the subsurface to the air/water interface is faster for the C12EOx surfactants than the C12EOxPO3 surfactants (long time data).

Hydrogen-bonded mesomorphic complexes combining hydrophilic and fluorophilic molecular segments.

A 2,4-diamino-6-phenyl-1,3,5-triazine carrying a single oligo(ethylene oxide) (EO) chain has been investigated in binary mixtures with two-chain and three-chain semiperfluorinated benzoic acids. Mixtures of the triazine with three equivalents of the complementary acids exhibit a hexagonal columnar (Colh) mesophase. Docking of three acid molecules to the diaminotriazine nucleus leads to the formation of disc-like aggregates with a central hydrogen-bonded polar core surrounded by the peripheral fluoroalkyl chains, which self-assemble in columns arranged on a hexagonal lattice. The polar EO chains at the triazine cores do not segregate into a distinct sub-space but are included into the polar cores, providing increased flexibility of the cores with respect to conformations and available hydrogen bonding sites. In equimolar (1 : 1) triazine/benzoic acid mixtures macroscopic phase separation of excess triazine from the columnar LC phases occurs. These Colh phases are formed by [1 : 3] or [2 : 4] complexes, depending on the number of fluorinated chains. However, some of the excess triazine component is accommodated within the polar column cores, contributing to space filling and providing additional hydrogen bonding along the columns. Thus the EO chain, despite of being fixed at the periphery, assemble in the core region of the aggregates, this is distinct from the self-assembly of related alkyl or semiperfluoroalkyl substituted diaminotriazines with fluorinated benzoic acids, forming discrete disc-like [1 : 3] or rod-like [1 : 1] complexes. Obviously, the flexible EO chains decrease the effect of the aggregate shape on self-assembly and lead to an increased contribution of general amphiphilicity to self-assembly.

Liquid chromatography coupled to quadrupole-Orbitrap high resolution mass spectrometry based method for target analysis and suspect screening of non-ionic surfactants in textiles

In this study, we describe a high-throughput and sensitive method for textiles analysis, using liquid chromatography coupled to quadrupole-Orbitrap high resolution mass spectrometry (LC-Q-Orbitrap HRMS), for the simultaneously quantitative analysis of 40 target alkylphenol polyethoxylates (APEO) oligomers with reference standards and screening of 160 alcohol polyethoxylates (AEO) oligomers without standards in textiles. The APEOs contain nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) with an EO number of ethylene oxide of 1–20, while AEOs focus on C11EOs-C18EOs with an EO number of 1–20. After ultrasonic extraction in methanol, the extract was directly separated using a core-shell CORTECS C18+ column and analyzed by Full MS/dd-MS2 (data dependent acquisition) scan in ESI positive mode. Two best sensitivity experimental conditions for APEOs with short EO chains (AP(EO)1-2) and long EO chains (AP(EO)3-20) were investigated, respectively. Most APEO oligomers had wide concentration ranges and the correlation coefficients (R2) were higher than 0.999. The limit of quantitation (LOQ) values for NP(EO)3-20 oligomers ranges from 16.00 to 52.80μg/kg and for OP(EO)3-20 oligomers is from 2.40 to 8.00μg/kg. LOQ for NP(EO)1 and NP(EO)2, OP(EO)1 and OP(EO)2 was 2.40mg/kg and 0.24mg/kg, 1.20mg/kg and 0.16mg/kg, respectively. The average recovery for each APEO oligomer in cotton and polyester matrix was between 78% and 110% at three spiked levels and the relative standard deviation (RSD%) was below 10%. As to AEOs suspects, a HRMS compound database containing 160 AEO oligomers was built and several parameters such as exact m/z, isotopic patterns, predicted product ions and predicted retention time were used for screening and confirmation. The established method was successfully applied for analysis of 40 commercial textile samples. Compared with OPEOs, NPEOs, especially NP(EO)3-15 oligomers, were widely detected in samples and the total concentration ranged from 1.56 to 1376.31mg/kg. AEOs were also found in most samples, among which C12-14, C16 and C18 compounds appeared more frequently and the EO chains mainly ranged from 3 to 15.

Glucose triggered enhanced solubilisation, release and cytotoxicity of poorly water soluble anti-cancer drugs fromT1307 micelles

Tetronic® 1307 (here after written as T1307) is a hydrophilic ethylene oxide-propylene oxide (EO-PO) star block copolymer with long EO chains (Total MW- 18000 and 70% EO). Although biocompatible, its use as a nanocarrier is restricted owing to its high critical micelle concentration (CMC) and temperature (CMT). We examined if the addition of glucose, a common pharmaceutical ingredient promotes micellization. Scattering and thermal studies show formation of stable unimodal micelles and cloud point (CP) decreased linearly. The solubilization of anticancer drugs viz. curcumin (CN) and quercetin (QN) demonstrates improved controlled release kinetics and cytotoxicity. On the whole, modulation in micellar behaviour by glucose opens enchanting possibility of using T1307 micelles as nanoreservoirs.