Dimethyl Ammonium Bromide Research Articles

A lipidic delivery system of a triple vaccine adjuvant enhances mucosal immunity following nasal administration in mice

We previously developed an highly efficacious combination adjuvant comprised of innate defense regulator (IDR)-1002 peptide, poly(I:C) and polyphosphazene (TriAdj). Here we aimed to design and test the in vivo efficacy of a mucoadhesive nasal formulation of this adjuvant. To determine the physical properties of the formulation, the effect of addition of each individual component was characterised by gel electrophoresis and fluorescence quenching using rhodamine-poly(I:C). Cationic liposomes comprised of didodecyl dimethylammonium bromide (DDAB), dioleoyl phosphatidylethanolamine (DOPE) (50:50 or 75:25 mol:mol) and DDAB, L-α-phosphatidylcholine (egg PC) and DOPE (40:50:10 mol:mol:mol) were prepared by the thin-film extrusion method. The liposomes and TriAdj were combined by simple mixing. The formed complex (L-TriAdj) was characterized by dynamic light scattering, zeta potential, and mucin interactions. We found that IDR-1002 peptide, polyphosphazene and poly(I:C) self-assembled in solution forming an anionic complex. Exposure of RAW267.4 mouse macrophage cells to TriAdj alone vs. L-TriAdj indicated that DDAB/DOPE (50:50) and DDAB/EPC/cholesterol (40:50:10) complexation reduced TriAdj toxicity. Next, TriAdj-containing cationic liposomes were prepared at several molar ratios to determine optimal size, stability and desired positive charge. Transmission electron microscopy showed rearrangement of lipid structures on binding of liposomes to TriAdj and to mucin. Stable particles (<200 nm over 24 h) showed mucin binding of DDAB/DOPE + TriAdj was greater than DDAB/EPC/DOPE + TriAdj. To verify in vivo efficacy, mice were administered the DDAB/DOPE + TriAdj complex intranasally with ovalbumin as the antigen, and the immunogenic response was measured by ELISA (serum IgG1, IgG2a, IgA) and ELISpot assays (splenocyte IL-5, IFN-γ). Mice administered adjuvant showed a significantly greater immune response with L-TriAdj than TriAdj alone, with a dose-response proportionate to the triple adjuvant content, and an overall balanced Th1/Th2 immune response representing both systemic and mucosal immunity.

Communication—Bottom-Up TSV Filling Using Sulfonated Diallyl Dimethyl Ammonium Bromide Copolymer as a Leveler

A new leveler, sulfonated diallyl dimethyl ammonium bromide copolymer, exhibits the void-free through silicon via (TSV) bottom-up filling with 5 minutes. The leveler has been characterized by CVS measurements with different concentrations at different RDE rotation speeds. The results show that SDDABC assisted the formation of a strong inhibition layer on copper surface when 16 ppm concentration has been added. Furthermore, bottom-up TSV filling with nearly no deposit on TSV sidewall is achieved with 16 ppm of SDDABC. Also, the filling time of 20 × 45 μm TSV is only 5 minutes.

Preparation of surface-modified monodisperse polystyrene microspheres with cationic functional comonomer

A two-stage synthesis of surface-functionalized monodisperse polystyrene (PS) microspheres in ethanol/water medium by introducing methacryloyloxyethyl dodecyl dimethyl ammonium bromide (QDMDB) to dispersion polymerization of styrene is reported. Polyvinylpyrrolidone (PVP) and fatty alcohol polyoxyethylene ether (AEO-9) are used as dispersion stabilizers. The novel microspheres are characterized by FT-IR, SEM, GPC, TGA, water contact angle (WCA), etc. The dispersion polymerization goes through successfully with the solid content up to 58.75%, in which the water content in the medium is 20%. The water content in the medium has a certain effect on the particle size and molecular weight of microspheres. Under the experimental conditions, the average diameters of the obtained microspheres are approximately 550–1200 nm with the number average molecular weight of up to 5.8 × 105. The introduction of QDMDB improves the wettability and thermal stability of the poly(St-co-QDMDB) microspheres. A mechanism of dispersion copolymerization based on XPS and 1H NMR is proposed.

Rheo-SANS study on relationship between micellar structures and rheological behavior of cationic gemini surfactants in solution

HypothesisGemini surfactant 12–2–12 (dimethylene-1,2-bis(dodecyl dimethylammonium bromide)) solutions are known to show shear thickening and thinning under salt-free conditions. Because the rheological behavior of the wormlike micelles formed by 12–2–12 in solution is related to their structure, we expected that changes to the precursor structure would affect their rheological behaviors. It is also important to understand the effect of the introduction of a spacer group in the 12–2–12 molecules on the rheological behavior and structure of the wormlike micelles under shear flow. ExperimentsSimultaneous small-angle neutron scattering and rheological measurements (Rheo-SANS) of the 12–2–12 solutions were performed. We exhaustively studied the structural changes in the wormlike micelles upon increasing shear rate. FindingsWe found that the wormlike micelles were oriented in the direction of the flow due to elongation and that changes to the precursor of the wormlike micelles did not affect the shear thickening. As a precursor structural change of shear thinning, the wormlike micelles elongated while maintaining their orientation. We found that an increase in the molecular curvature of the 12–2–12 due to the introduction of a spacer-group contributed to the unusual rheological behaviors of the wormlike micelles in a solution under shear flow.

Synergistic effect of cationic gemini surfactants and butanol on the corrosion inhibition performance of mild steel in acid solution

The synergistic effect of gemini surfactants (GS) 1,2-ethane bis(dimethyl alkyl ammonium bromide) (CmH2m+1) (m-2-m, m = 10 and 12) and n-butanol (C4OH) on the corrosion of mild steel in 1 M HCl solution has been investigated using gravimetric method, electrochemical methods (PDP and EIS) and scanning electron microscopy (SEM). Experimental outcome suggests that the inhibition efficiency (η) of m-2-m GS is considerably improved in the presence of butanol. The values of synergism parameter (Sθ) are greater than unity, indicating high η caused by the addition of C4OH to m-2-m GS is due to a co-operative adsorption. Polarization studies showed that the m-2-m GS in the presence or absence of C4OH are mixed-type inhibitors. Analysis of variance (ANOVA) reveals that the difference existing between inhibition efficiencies obtained by PDP, EIS and gravimetric techniques is statistically insignificant. The adsorption of studied inhibitors on mild steel surface in 1 M HCl solution followed the Langmuir adsorption isotherm. Surface morphology was studied using SEM and AFM. Some quantum chemical parameters and the Mulliken charge densities for m-2-m GS were calculated by the ORCA programme to provide further insight into the inhibition mechanism of the corrosion process.

Microwave/ultrasound-assisted modification of montmorillonite by conventional and gemini alkyl quaternary ammonium salts for adsorption of chromate and phenol: Structure-function relationship

Butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA) and dodecyl trimethyl ammonium bromide (DTMA) in same stoichiometric amounts were applied to modify montmorillonite (Mt) under microwave and ultrasound conditions. The composition and structure of products were obtained through multiple characterizations including XRD, FTIR, TG/DTG, SEM, TEM, and N2 adsorption/desorption measurements, and the adsorption performance of chromate and phenol on these products were also investigated. Intercalations of gBDDA and DTMA into interlayer space of Mt were observed, but the amount of anchored modifier on the external surface was larger for gBDDA compared with DTMA when the stoichiometric amount of modifier larger than 1.0 times cation exchange capacity of Mt was added. Although there was no significant difference in morphology among products, the interlayer space distance, specific surface area, and pore size distribution were closely associated with the species and amount of applied modifier. Adsorption of phenol on products through partition mechanism relied on not only organic content, but also the configuration of modifier. Meanwhile, adsorption of chromate mainly depended on the presence of counter ion (bromide), which accounted for the high adsorption capacity and initial adsorption rate on gOMt-0.75. The fitting parameters of adsorption results using pseudo-second order model and Freundlich model suggested that gBDDA-modified Mt could sequester phenol or chromate in the faster manner with higher affinity. Compared with the conventional surfactant such as DTMA, the study revealed that, using gemini surfactant such as gBDDA to modify Mt would significantly reduce or even has the potential to eradicate the secondary pollution by modifier release during adsorption process. This study provides a new direction for Mt modification intended to be used as adsorbents to treat polluted water with high standards such as drinking water.

Human In Situ Study of the effect of Bis(2-Methacryloyloxyethyl) Dimethylammonium Bromide Immobilized in Dental Composite on Controlling Mature Cariogenic Biofilm.

Cariogenic oral biofilms cause recurrent dental caries around composite restorations, resulting in unprosperous oral health and expensive restorative treatment. Quaternary ammonium monomers that can be copolymerized with dental resin systems have been explored for the modulation of dental plaque biofilm growth over dental composite surfaces. Here, for the first time, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM) on human overlying mature oral biofilms grown intra-orally in human participants for 7–14 days. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected to determine bacterial counts via colony-forming unit (CFU) counts. Biofilm viability, chronological changes, and percentage coverage were also determined through live/dead staining. QADM composites caused a significant inhibition of Streptococcus mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that: (1) QADM composites were successful in inhibiting 1–3-day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of the S. mutans group; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. Contact-killing strategies using dental materials aimed at preventing or at least reducing high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of the recurrence of dental caries around composites.

Insights into the Interactions of Sulfamethoxazole with Organized Assemblies of Ionic and Nonionic Surfactants.

This work reports the physicochemical behavior of antibiotic drug sulfamethoxazole (SMX) in the presence of different surfactants, viz., cetyl trimethyl ammonium bromide (CTAB), dodecyl trimethyl ammonium bromide, didodecyl dimethyl ammonium bromide, sodium dodecyl sulfate, sodium deoxycholate, Tween 80, and Tween 20. The drug-surfactant systems were studied by UV-visible and fluorescence spectroscopies to assess the binding constants ( Kb), partition coefficient ( Kx), free energy of partition (Δ Gp), aggregation number ( Nagg), and quenching constant ( KSV). Solubilization studies were carried out to understand the encapsulation efficiency of the system, which was found to increase as a function of CTAB concentration. Surface tension measurements enabled us to determine the change in critical micelle concentration as well as to calculate the variation in surface parameters of surfactant in the presence of drug, viz., surface pressure (π), surface excess concentration (γmax), and minimum area ( Amin). In addition, UV-visible, fluorescence, and circular dichroism studies were carried out to check the effects of surfactant-based SMX formulation on serum proteins.

Role of (single/double chain surfactant) micelles on the protein aggregation

To investigate the interaction between the bovine serum albumin (BSA) and cationic surfactants (monomeric, cetyltrimethylammonium bromide, CTAB) and dimeric/gemini, 1, 6 bis (N, N-hexadecyl dimethyl ammonium bromide, 16-6-16) and to find out the role of micelles in the aggregation of the protein using spectroscopic (UV–visible, fluorescence, fluorescence lifetime measurements, circular dichroism (CD), etc.) and microscopic (atomic force microscope (AFM)) techniques. The different surfactant has an effect on the polarity of the microenvironment of the protein shows in all the spectroscopic technique at below and above the critical micelle concentration (CMC). The far-UV CD spectra show that BSA is more disrupted by the dimeric surfactant compared to the monomeric CTAB above the CMC. The binding of the surfactant induce changes in the microenvironment around the aromatic amino acids residues and disulfide bond of the BSA at different pHs. The binding constant values were found to be 20.278×103M and 8.443M for the BSA-CTAB complex and BSA-16-6-16 complex, respectively. Atomic force microscope indicates the aggregation is more in case of dimeric (16-6-16) surfactant compared to the monomeric (CTAB) surfactant at the higher concentration (above their CMCs). Below and above the CMC, all changes are noticeable.

Solid separation from the heavy oil sludge produced from Liaohe Oilfield

Heavy oil sludge usually exists in the form of stable W/O emulsion, in which the water droplets were stabilized by natural surfactants and small solid particles. The oil recovery from the oil sludge is valuable, but the demulsification by using regular demulsifiers could be hindered by the solids. Therefore, the solid separation is important for oil recovery. In this paper, firstly, properties of heavy oil sludge produced from the Liaohe Oilfield were analyzed. Then, a multistage chemical treatment was proposed and chemicals were screened for solid separation. Limonene, sodium sulphate solution, (dioctadecyl dimethyl ammonium bromide + citric acid) were chosen for different purposes at different stages, respectively. At last, the rational separation conditions were investigated. After the treatment, the solid content in oil decreased from 18.57% to be 0.9% by mass. In addition, the mixture of recovered oil and fresh crude oil can be dehydrated easily by using regular demulsifiers.

An intermittent amyloid phase found in gemini (G5 and G6) surfactant induced β-sheet to α-helix transition in concanavalin A protein

Surfactant-induced amyloid fibrillation has many implications in laboratory and industry. Previously, cetyltrimethylammonium bromide (CTAB; C19H42BrN) induced amyloid formation in concanavalin A (ConA) has been reported by authors (Khan, JM et al., 2016 A). In this work, cationic gemini surfactants pentanediyl‑1,5‑bis (dimethylcetylammonium bromide); 16-5-16 (G5), and hexanediyl‑1,6‑bis (dimethyl cetyl ammonium bromide); 16-6-16 (G6) were found to induce amyloid-like aggregation in ConA as studied with turbidity at 350 nm, Rayleigh scattering and Thioflavin T (ThT) binding assay and Far UV CD. The sizes of the aggregates were characterized with dynamic light scattering (DLS) and atomic force microscopy (AFM). Hydrodynamic radii (Rh) of the aggregates were found to be 74 nm and 122 nm with 50 μM of G5 and G6 respectively. Even at 7.5 μM, gemini surfactants seems disrupting hydrophobic pockets of ConA and result in aggregation. On the contrary, aggregation disappeared around 250 μM surfactant concentration with β-sheet → α-helix transition. The re-establishment of intra-molecular hydrogen bonding may have resulted in the formation of non-native α-helical structures. Alcohols, predominantly 2,2,2‑trifuloroethanol (TFE), have been reported to induce α-helices in β-sheet proteins by solvent engineering. There are very few reports of β-sheet to α-helix transition induced by non-alcoholic substances. Our lab is pioneer in reporting surfactant (CTAB) induced β-sheet to α-helix transition in ConA (Khan, JM et al., 2016 A). This is the first report of G5 and G6 gemini surfactant induced β-sheet to α-helix transition, as per our knowledge. ConA being apoptotic to cancerous cells and having potential therapeutic effect on hepatoma, the observations done in this work could be of immense interest in vesicular delivery of ConA.

Short-Chain n-Alcohol-Induced Changes in Phase Behaviors of Aqueous Mixed Cationic/Anionic Surfactant System.

The short-chain n-alcohol-induced changes in phase behaviors of aqueous mixed 1,3-propanediyl bis(dodecyl dimethylammonium bromide) (12-3-12) and sodium dodecyl sulfonate (AS) system have been investigated. For the 12-3-12/AS/H2O mixed system, there are two kinds of aqueous two-phase systems with excess cationic surfactant (ATPS-C). The molar ratio of 12-3-12 to AS (MR12-3-12/AS) and the total surfactant concentration ( mT) in the top phase are smaller than those in the bottom phase of ATPS-C. It is worth noting that the addition of ethanol or n-propanol leads to different influences on the ATPS-C. Molecular dynamics (MD) simulation results illustrate that the different influences ascribe to the difference in the cosurfactant effect of ethanol and n-propanol. When ethanol is used as additive, the difference in mT leads to the difference in interactions between surfactants and ethanol for the two coexisting phases of ATPS-C, determining the difference in their combination ability with the mixed solvent. It is the main reason for the ethanol-induced phase inversion of the first kind of ATPS-C. When n-propanol is added, in addition to mT, MR12-3-12/AS is also a key factor influencing the interactions between 12-3-12 and AS and between surfactants and n-propanol due to the stronger cosurfactant effect of n-propanol. MD simulations indicate that vesicles with smaller MR12-3-12/AS are easier and faster to form. These vesicles spontaneously accumulate at the top phase accompanied by certain amount of mixed solvent transferred from the bottom phase of ATPS-C. Meanwhile, the competition for the mixed solvent arising from the surfactant-rich bottom phase prevents the transferring. The two factors work together to cause the increase of mT in the top phase of ATPS-C with the addition of n-propanol, leading to n-propanol-induced phase concentration inversion rather than phase inversion of ATPS-C. On the basis of the experimental results and MD simulations, ethanol-induced phase inversion mechanism or n-propanol-induced phase concentration inversion mechanism of ATPS-C has been proposed.

Redox-controlled reversible micelles transition and lyotropic liquid-crystalline behavior of novel polymerizable ferrocenyl surfactants

A novel photopolymerizable surfactant with ferrocenyl group, (11-ferrocenylundecyl) (ethyl methacrylate) dimethylammonium bromide (I+), was synthesized through the reaction of 11-bromoundecyl ferrocene and N,N-(dimethylamino) ethyl methacrylate. Based on the results of voltammetric cycle, the small potential difference ΔE was 72 mV, which indicates that the I+ has good redox reversibility. The critical micellar concentration (CMC) values were about 0.5 and 22.7 mM for I+ in the reduction (CMCred) and oxidation state (CMCox) and it could aggregate and disaggregate by using redox reaction and photopolymerization when its concentrations was between their CMCred and CMCox values. The lyotropic liquid-crystalline properties of I+ in water were investigated by X-ray diffraction (XRD) and plarized optical microscope (POM). The results indicate when the concentration of the I+ solution over 40 wt %, an ordered lamellar liquid crystal structure was formed. With increasing concentration, the nanoscopic long-range order improved. Moreover, the lyotropic liquid-crystalline properties of I+ could also be controlled by using redox reaction and photopolymerization. In a word, the novel polymerizable ferrocenyl surfactants are good environmental responsive materials and can potentially act as the drug carrier and the scavenger for removing dissolved organic impurities in water.

Preparation of Dodecyl Dimethyl Benzyl Ammonium Bromide-Doped Cubic CaCO3 with Antibacterial Properties

CaCl2 encapsulated was placed in the hydrothermal reactor of an aqueous solution of Na2CO3 and dodecyl dimethyl benzyl ammonium bromide for synthesis of two samples of calcium carbonate by an improved hydrothermal method and one-pot method. Their crystal structure, morphology, chemical composition, and thermal stability of the synthesized samples of calcium carbonate were investigated by XRD, FTIR, SEM, EDS and TGDSC. The sterilization activity of the as-prepared samples was evaluated by killing of Sarcina lutea bacteria. The results indicated that the regular cube capsule-assisted calcium carbonate prepared by hydrothermal process was doped with dodecyl dimethyl benzyl ammonium bromide. Under the same condition, the spindle-shaped calcium carbonate synthesized the one-pot method was not doped with dodecyl dimethyl benzyl ammonium bromide. Among the samples of calcium carbonate, capsule-assisted calcium carbonate had shown better antibacterial effect for Sarcina lutea: in 48 h after its inhibition a zone diameter was 12.3 mm.

Synthesis and Structure-Property Relationships in Herbicidal Ionic Liquids and their Double Salts.

In this study, two homologous series of novel herbicidal ionic liquids (HILs) were synthesized in a simple metathesis reaction between alkyl[2-(2-hydroxyethoxy)ethyl]dimethylammonium bromides and alkali metal salts of 4-chloro-2-methylphenoxyacetic acid (MCPA) or 3,6-dichloro-2-methoxybenzoic acid (dicamba), known as popular herbicides from the class of growth regulators. These HILs were subsequently mixed to prepare double-salt herbicidal ionic liquids (DSHILs). The DSHILs were characterized by substantially altered parameters of viscosity, refractive index, glass transition temperatures and surface activity compared to the average values expected for ideal mixtures of their individual components (HILs). Interestingly, DSHILs possessed superior physicochemical properties such as relatively low viscosity or facilitated formation of micelles, which emphasizes the complex nature of multi-ion interactions in the microstructures of ionic liquid mixtures. The biological tests showed improved efficiency of DSHILs against tested weeds compared to the reference herbicides and parent HILs.

Surface‐Passivated Cesium Lead Halide Perovskite Quantum Dots: Toward Efficient Light‐Emitting Diodes with an Inverted Sandwich Structure

AbstractIn recent years, metal‐halide perovskite quantum dots (QDs) have been broadly applied in optoelectronic fields due to their fascinating characteristics, such as high photoluminescence quantum yields, tunable bandgaps, and low‐cost solution processing. Here, a facile ligand‐exchange strategy is employed for the fabrication of CsPbBr3 QDs capped with di‐dodecyl dimethyl ammonium bromide. It is demonstrated that the treated QDs' film becomes more compact with higher electron mobility and shorter lifetime. Besides, a reduced conduction band minimum value (0.28 eV) of perovskite QDs' film provides an efficient electron injection to them from ZnO nanoparticles. Through using the well‐passivated QDs' film, electroluminescence QD light‐emitting diode (QLED) devices with an indium tin oxide/ZnO/CsPbBr3 QDs/MoO3/4, 4′‐bis(carbazole‐9‐yl)biphenyl/Al inverted sandwich structure are achieved. The as‐prepared QLED device exhibits a maximum current efficiency of 0.62 cd A−1 and an external quantum efficiency of 0.58%, which is nearly nine times higher than that of the device based on unmodified QDs. More importantly, the stability testing results demonstrate that the QLED can be operated for more than 20 min under ambient conditions without any encapsulation. This provides an alternative route for highly efficient perovskite‐based LED with inverted sandwich structures.

The study of effect of didecyl dimethyl ammonium bromide on bacterial and viral decontamination for biosecurity in the animal farm.

Aim:The aim of this study was to determine the effectiveness of the fourth-generation quaternary ammonium compounds, didecyl dimethyl ammonium bromide (DDAB), on the efficacy of bacterial and viral decontamination against pathogens commonly found in livestock industry including Salmonella infantis (SI), Escherichia coli, and avian influenza virus (AIV).Materials and Methods:The DDAB was prepared at 500, 250, and 125 parts per million (ppm) for absent and present organic material. Meanwhile, 5% of fetal bovine serum in DDAB solution sample was used to mimic the presence of organic material contamination. 400 µl of each DDAB concentration was mixed with 100 µl of each pathogen (SI, E. coli, and AIV) and then incubated at room temperature or 4°C at various time points (5 s, 30 s, 1 min, 5 min, 10 min, 15 min, and 30 min). The activity of DDAB treatment was stopped using 500 µl of FBS. Each treatment sample was titrated on either deoxycholate hydrogen sulfide lactose agar plates or Madin-Darby canine kidney cells for bacteria and AIV, respectively. Each treatment was conducted in triplicates, and the pathogen inactivation was considered effective when the reduction factor was ≥3 log10.Results:Our current study revealed that the DDAB inactivated SI, E. coli, and AIV under the various concentrations of DDAB, organic material conditions, exposure temperature, and exposure timing. In addition, the comparison of bactericidal and virucidal efficacy indicated that bacteria were more susceptible to be inactivated by DDAB as compared to viruses. However, DDAB showed marked inactivated differences in the absence or presence of organic materials.Conclusions:The DDAB may be a potential disinfectant for inactivating bacteria and viruses, especially enveloped viruses, in livestock farms. It can be useful as a disinfectant for biosecurity enhancement on and around animal farm.

Adsorption of phenol from aqueous solutions using interlayer modified titanate nanotubes

AbstractBACKGROUNDLayered titanate nanostructures have long been studied as efficient adsorbents for different kinds of pollutants such as heavy metals and dye cations. As to the electro‐neutral and anionic organic pollutants, titanates show relatively low adsorption capacity due to a negatively charged surface and lack of organophilic affinity. This research focuses on the interlayer modification of titanate nanotubes for adsorption of this kind of organic pollutants. Phenol was chosen as a representative target.RESULTSTwo surfactants, hexadecyl trimethyl ammonium bromide (HTAB) and dodecyl dimethyl benzyl ammonium bromide (DDBAB), were chosen as organic modifier for the interlayer modification. Detailed characterization proved that surfactant molecules were intercalated into the interlayer and surface properties of titanates were successfully modified. Adsorption behavior of phenol was then systematically investigated. Results show that DDBAB modified titanates are efficient phenol adsorbents, possessing better performance than HTAB modified titanates. The high adsorption capacity is attributed to the special structure of titanates and the affinity between phenyl groups in DDBAB and phenol. Subsequently, thermally induced phase change of spent adsorbents led to complete regeneration.CONCLUSIONInterlayer modified titanate nanotubes were efficient phenol adsorbents with a maximum adsorption capacity of 226.24 mg g‐1. Complete regeneration of spent adsorbents was also achieved. © 2018 Society of Chemical Industry

Macroporous temperature‐sensitive gels with fast response: Comparison of preparation methods

ABSTRACTApplication of thermo‐responsive gels as soft actuators for microfluidic devices with repeating “open–close” cycles requires high rates of water transport driven by changes in temperature. These rates are conventionally evaluated by comparison of water retention curves in T‐jump tests with fixed initial and final temperatures. A shortcoming of this method is that it does not allow changes in diffusivity with temperature to be assessed quantitatively. To characterize cooperative diffusivity of water molecules, we propose a novel approach based on modeling the responses of temperature‐sensitive gels in equilibrium swelling tests and T‐jump experiments. Analysis of observations on poly(N‐isopropylacrylamide) gels synthesized in aqueous solutions of pore‐forming agents reveals that formation of a macroporous structure in a gel is a necessary, but not sufficient condition for acceleration of water transport. The effect of cosolvents used under preparation (phenol, ethanol, methanol, diethyl ether, dioxane, sucrose, and dodecyl dimethyl benzyl ammonium bromide) on water diffusivity is studied in detail. It is shown that the most pronounced enhancement of diffusivities under deswelling and reswelling is reached when the gels are synthesized in aqueous solutions of the surfactant at subzero temperatures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46353.

Optimizing the Crystallinity and Phase Separation of PTB7:PC71BM Films by Modified Graphene Oxide

A facile method is proposed to obtain modified shorn graphene oxide (DDAB-sGO) with improved dispersion in organic solvents. Didodecyl dimethylammonium bromide (DDAB)-sGO, which exhibits good dispersibility in the nonpolar solvent o-dichlorobenzene, was obtained via the sono-Fenton reaction and DDAB ionic functionalization. DDAB-sGO was used in the preparation of conjugated polymer:fullerene blend composites. UV–visible absorption spectra, steady-state photoluminescence spectra, fluorescence decay, and grazing incidence X-ray scattering measurements were applied to characterize morphologies, structural features, and charge-transport characteristics of the composites. Doped into poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) conjugated polymer blends, DDAB-sGO is shown to facilitate increased crystallinity and phase separation of PTB7 and PC71BM to achieve a m...