Hydrophobic Alkyl Tail Research Articles

Flower-like CuO light traps as anti-wetting armor of Janus membrane for spraying wastewater treatment by photothermal membrane distillation

Current scientific advances in wastewater treatment have slowed the pressure on water access. Membrane distillation (MD) was a promising technology for wastewater treatment. However, for the treatment of the spraying wastewater containing high boiling point organic solutions, high energy dependence and membrane wetting by the water-soluble organics with high concentrations were the limitations of the MD process. Herein, Janus photothermal membranes (JPTM) were prepared by chemical plating and then surface oxidation under alkaline conditions. The flower-like CuO hydrophilic photothermal layer which acted as the light trap and anti-wetting armor was constructed on the PVDF hydrophobic membrane surface. In the process of photothermal membrane distillation, when the CuO hydrophilic photothermal layer contacted with feed solution, due to the arrangement of the hydrophilic hydroxyl heads of the organics on the hydrophilic photothermal layer, and the hydrophobic alkyl tails faced the water molecules and repelled them. The light was trapped in the hydrophilic photothermal layer and repeatedly refracted by the flower-like CuO. The flower-like CuO was further optimized by controlling alkali concentration. When the alkali concentration was 2.5 M, the photothermal conversion of JPTM with the moonflower-like CuO hydrophilic photothermal layer was up to 92.86%. When single component high boiling point organic solutions (BCS or DB) were treated by MD, under 1 sun irradiation (1 kW m−2), the permeate fluxes achieved 2.68 and 2.91 kg m−2 h−1 with over 98% removal of organics; Further, for the treating of spraying wastewater, it had a high permeate flux of 5.13 kg m−2 h−1, a photothermal efficiency of 90.79%, and a removal rate of 62%. The JPTM was a low-carbon technology to improve heat and mass transfer for wastewater treatment by photothermal membrane distillation.

Hexamethylenetetramine additive with zincophilic head and hydrophobic tail for realizing ultra-stable Zn anode

Aqueous zinc batteries are regarded as one of the promising next-generation energy storage batteries due to their high safety and low cost, however, one of the most important problems limiting their commercialization is the cyclic stability of the zinc anode. Therefore, in this work, we first employed hexamethylenetetramine (HMT) as the electrolyte additive to in-situ construct a Zn-HMT complex film to stabilize the zinc anode. After adding the HMT, its zincophilic head will be prior to adsorbing on the zinc foil to form Zn-HMT complex film and then introduce uniform zinc deposition, and simultaneously the formed Zn-HMT complex with hydrophobic alkyl tail will repel the H2O from combining with Zn2+ to form Zn4SO4(OH)6·nH2O by-product as well as the hydrogen evolution reaction (HER). As a result, the HMT-based electrolyte promotes ultra-stable zinc anode cycling for as long as 2000 h with extremely high average Coulombic efficiency (99.51 %). When applied in the Zn-V2O5 full cell, it also demonstrates outstanding electrochemical performances with a reversible capacity as high as 197.8 mAh/g after 500 cycles. This work provides a simple and effective method for the implementation of high-safety and high-stable aqueous zinc-ion batteries.

Highly Conductive Sulfide Solid-State Electrolytes for All-Solid-State Li Battery

The All-Solid-State Battery (ASSB) Is a Promising Next-Generation Energy Storage Technology for Both Consumer Electronics and Electric Vehicles Because of Its High Energy Density and Improved Safety. Sulfide Solid-State Electrolytes (SSEs) Have Merits of Low Density, High Ionic Conductivity, and Favorable Mechanical Properties Compared to Oxide Ceramic and Polymer Materials. However, Mass Production and Processing of Sulfide SSEs Remain a Grand Challenge Because of Their Poor Moisture Stability. Here We Report a Reversible Surface Coating Strategy for Enhancing the Moisture Stability of Sulfide Sses By Using Amphipathic Organic Molecules. an Ultra-Thin Layer of 1-Bromopentane Is Coated on the Sulfide SSE Surface (e.g., Li7P2S8Br0.5I0.5) Via Van Der Waals Force. 1-Bromopentane Has More Negative Adsorption Energy with SSE Than H2O Based on First-Principles Calculations, Thereby Enhancing the Moisture Stability of SSE Because the Hydrophobic Long-Chain Alkyl Tail of 1-Bromopentane Repels Water Molecules. Moreover, This Amphipathic Molecular Layer Has a Negligible Effect on Ionic Conductivity and Can be Removed Reversibly By Heating at Low Temperatures (e.g., 160°C). This Finding Opens a New Pathway for the Surface Engineering of Moisture-Sensitive SSEs and Other Energy Materials, Thereby Speeding up Their Deployment in ASSBs.

A study involving PC-3 cancer cells and novel carbamate gemini surfactants: Is zeta potential the key to control adhesion to cells?

Liposome surface potential effect on cellular uptake and cytotoxicity is evaluated using liposomes, modified with cationic lipid DOTAP, a series of cationic gemini surfactants with two carbamate fragments, and an amphiphilic peptide SSRGD. The surfactants used are novel representatives of the gemini family with improved self-assembling activity coupled with potential biodegradable properties and displayed increasing antibacterial activity and cytotoxicity with the shortening of hydrophobic alkyl tails. The longest alkyl tail surfactant, 14-6-14(Et), was the most biocompatible of the series, which was chosen for liposome modification. Prepared liposomes of various compositions are characterized from morphological and physicochemical standpoints in order to optimize their biocompatibility and stability. The carbamate gemini surfactants were also twice as effective at providing positive charge to liposomes and less toxic compared to DOTAP. On their own, carbamate surfactants were able to increase cellular uptake of liposomes by 190%. The mixed composition of 14-6-14(Et) surfactant and SSRGD amphiphilic peptide was the most readily absorbed formulation among different tested neutral, cationic and RGD-modified liposomes. The comparison between the cellular uptake promotion is conducted as to what is the most selective and efficient approach to enhance lipid nanoparticle uptake by cancerous cells.

Enhancing Moisture Stability of Sulfide Solid-State Electrolytes by Reversible Amphipathic Molecular Coating.

The all-solid-state battery (ASSB) is a promising next-generation energy storage technology for both consumer electronics and electric vehicles because of its high energy density and improved safety. Sulfide solid-state electrolytes (SSEs) have merits of low density, high ionic conductivity, and favorable mechanical properties compared to oxide ceramic and polymer materials. However, mass production and processing of sulfide SSEs remain a grand challenge because of their poor moisture stability. Here, we report a reversible surface coating strategy for enhancing the moisture stability of sulfide SSEs using amphipathic organic molecules. An ultrathin layer of 1-bromopentane is coated on the sulfide SSE surface (e.g., Li7P2S8Br0.5I0.5) via Van der Waals force. 1-Bromopentane has more negative adsorption energy with SSEs than H2O based on first-principles calculations, thereby enhancing the moisture stability of SSEs because the hydrophobic long-chain alkyl tail of 1-bromopentane repels water molecules. Moreover, this amphipathic molecular layer has a negligible effect on ionic conductivity and can be removed reversibly by heating at low temperatures (e.g., 160 °C). This finding opens a new pathway for the surface engineering of moisture-sensitive SSEs and other energy materials, thereby speeding up their deployment in ASSBs.

Quantum molecular modeling of oxazolidines as detergent-dispersant additives for gasoline: A valuable technological adviser

Patented detergent-dispersant (DD) additives based on oxazolidines [1] were quantum-mechanics modeled in order to get molecular-level insights into their functionality for removing and preventing formation of gum deposits in gasoline internal-combustion engines. The DDs are derived from polyalkenyl N-hydroxyalkyl succinimides whose polarities were modulated through a radical (R) substituent which can be either a phenol derivative (phenyl, 2-hydroxy-), pentyl or atomic hydrogen attached to the oxazolidine ring. We propose a mechanism for the performance of DDs consisting in the attraction of gum molecules by the DDs’ polar heads and their subsequent transference onto the DDs’ hydrophobic alkyl tails. Density-Functional-Theory (DFT) calculations of electrostatic properties and interaction energies support the above molecular mechanism, and furthermore make the prediction that the best performance is reached when R = atomic hydrogen, as it was found through experimental tests [1]. DFT also allowed to realize that gum agglomerates within gasoline because the attractive interaction among gum monomers is stronger than among gum and gasoline molecules due to the gum’s high polarity induced by the carbonyl and alkene functional groups. Likewise, these functional groups are responsible for gum to adhere firmly to oxidized metallic surfaces in contact with gasoline because they complete the octahedral coordination of the exposed superficial iron atoms, reaching at this manner the same strongest spin polarization that iron atoms have at the bulk crystalline oxidized metal. However, the oxazolidine-based DDs remove deposited gum since they adhere stronger to these surfaces than gum does because their polar heads have more bonding sites than gum, the DD having the radical hydrogen being easiest to be desorbed after gum removal avoiding so be burned by sticking to the metallic surface during gasoline combustion.

Study of sodium lignosulfonate prepare low-rank coal-water slurry: Experiments and simulations

Abstract The effect of sodium lignosulfonate (SL) as additive on the preparation of low-rank coal-water slurry (LCWS) was studied by experiments and molecular dynamics (MD) simulations. The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration. Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface, and ∆ Gads0 was negative, proving that the reaction was spontaneous. Zeta potential measurements showed that SL increased the negative charge on coal. FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption, and it was found that the content of oxygen functional groups on coal increased after adsorption. Simulation results show that when a large number of SL molecules exist in the solution, some SL molecules will bind to hydrophobic hydrocarbon groups on coal. The rest of the SL molecules, their hydrophobic alkyl tails, come into contact with each other and aggregate in solution. The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction, which is conducive to the even dispersion of coal particles. The results of mean square displacement (MSD) and self-diffusion coefficient (D) show that the addition of SL reduces the diffusion rate of water molecules. Simulation results correspond to experimental results, indicating that MD simulation is accurate and feasible.

Hydrophobic tail length in spin crossover active iron(ii) complexes predictably tunes T½ in solution and enables surface immobilisation

Linear correlation of the hydrophobic alkyl tail length R employed in [FeII(LH-OR)(NCBH3)2] with the spin crossover switching temperature is a very convenient method of predictably tuning the iron(ii) spin state.

Therapeutic Peptide Amphiphile as a Drug Carrier with ATP-Triggered Release for Synergistic Effect, Improved Therapeutic Index, and Penetration of 3D Cancer Cell Spheroids.

Despite the great progress in the field of drug delivery systems for cancer treatment over the last decade, many challenges still lie ahead, such as low drug loading, deep penetration of tumors, side effects, and the development of drug resistance. A class of cationic membrane lytic peptides has shown potential as an anticancer agent by inducing cancer cell death via membrane disruption; meanwhile, their intrinsic selectivity renders them as having low cytotoxicity towards noncancerous cells. Here, we report the use of a cationic peptide amphiphile (PA), named PAH6, to load doxorubicin (Dox) that is intercalated in an ATP-binding aptamer-incorporated DNA scaffold. The PA contains a cationic lytic sequence, (KLAKLAK)2, a polyhistidine segment for the “proton sponge” effect, and a hydrophobic alkyl tail to drive the self-assembly. Dox-loaded DNA was found to form a spherical nanocomplex (NC) with PAH6 with particle sizes below 100 nm at various ratios. Since the carrier PAH6 is also a therapeutic agent, the drug loadings of the NC reached up to ~86% within the ratios we tested, and Dox was released from the NC in an ATP-rich environment. In vitro studies indicate that the presence of PAH6 could permeabilize cell membranes and kill cells through fast membrane disruption and depolarization of mitochondrial membranes. The cytotoxicity tests were conducted using A549 nonsmall cell lung cancer cells and NIH-3T3 fibroblast cells. PAH6 showed selectivity towards A549 cells. Significantly, the Dox-DNA/PAH6 NC exhibited a synergistic effect against A549 cells, with the IC50 decreased up to ~90% for Dox and ~69% for PAH6 when compared to the IC50 values of the two components, respectively. Furthermore, the selectivity of PAH6 conferred to the complex an improved therapeutic index between A549 and NIH-3T3 cells. A 3D-cultured A549 spheroid model was adopted to test the capability of Dox-DNA/PAH6 for tumor penetration. The PAH6 or Dox-DNA/PAH6 complex was found to break the spheroids into pieces, while Dox-treated spheroids maintained their shapes. In summary, this work provides a new strategy for constructing nanomedicines using therapeutic agents to meet the features required by anticancer treatment.

High-Generation Amphiphilic Janus-Dendrimers as Stabilizing Agents for Drug Suspensions.

Pharmaceutical nanosuspensions are formed when drug crystals are suspended in aqueous media in the presence of stabilizers. This technology offers a convenient way to enhance the dissolution of poorly water-soluble drug compounds. The stabilizers exert their action through electrostatic or steric interactions, however, the molecular requirements of stabilizing agents have not been studied extensively. Here, four structurally related amphiphilic Janus-dendrimers were synthesized and screened to determine the roles of different macromolecular domains on the stabilization of drug crystals. Physical interaction and nanomilling experiments have substantiated that Janus-dendrimers with fourth generation hydrophilic dendrons were superior to third generation analogues and Poloxamer 188 in stabilizing indomethacin suspensions. Contact angle and surface plasmon resonance measurements support the hypothesis that Janus-dendrimers bind to indomethacin surfaces via hydrophobic interactions and that the number of hydrophobic alkyl tails determines the adsorption kinetics of the Janus-dendrimers. The results showed that amphiphilic Janus-dendrimers adsorb onto drug particles and thus can be used to provide steric stabilization against aggregation and recrystallization. The modular synthetic route for new amphiphilic Janus-dendrimers offers, thus, for the first time a versatile platform for stable general-use stabilizing agents of drug suspensions.

An Efficient Amphiphilic-Type Triphenylamine-Based Organic Hole Transport Material for High-Performance and Ambient-Stable Dopant-Free Perovskite and Organic Solar Cells.

A new set of simply structured triphenylamine-based small molecules are synthesized and evaluated as dopant-free hole transporting materials (HTMs) for high-performance perovskite solar cells (PSCs) and bulk heterojunction inverted organic solar cells (BHJ IOSCs). Surprisingly, the new amphiphilic-type HTM-1 (with internal hydrophilic groups and peripheral hydrophobic alkyl tails) showed better compatibility and performance than the actual target molecule, that is, HTM-2 in PSCs and BHJ IOSCs. Importantly, the HTM-1-based dopant-free PSCs and BHJ IOSCs exhibited high power conversion efficiencies (PCEs) of 11.45 % and 8.34 %, respectively. These performances are superior and comparable to those of standard HTMs Spiro-OMeTAD (2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene) and PEDOT:PSS (poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate) in PSCs and BHJ IOSCs, respectively. The enhanced device performance of the HTM-1-based PSCs is ascribed to its strong affinity towards the perovskite, properly aligned energy levels with respect to the perovskite valence band, and excellent hole transporting behavior. In addition, the well-organized energy levels of the HTMs showed excellent compatibility in BHJ IOSCs. The new amphiphilic-type HTM-based photovoltaic devices also showed long-term air stability over 700 h. These promising results offer new and unexpected prospects for engineering the interface between the photoactive material and HTMs in PSCs and BHJ IOSCs.

Preparation, surface activity and colloidal properties of the ionic complex of chitosan with hexadecyl-oligo-oxyethylene hemisuccinate

Chitosan polyelectrolyte complex with high surface activity has been prepared by salt complexation of chitosan with hexadecyl-oligo-oxyethylene hemisuccinate (HOS), an anionic surfactant. Physicochemical properties of chitosan–HOS complex can be explained by unusual structure of HOS which has the polyoxyethylene chain located between the polar carboxyl head group and the hydrophobic alkyl tail. Aqueous solutions of chitosan–HOS complex are structured systems with pronounced thixotropic properties. The effect of content of hydrophobic exchanged groups on the solution properties of chitosan–HOS complex and various factors controlling the stability of oil-in-water emulsions in the presence of chitosan–HOS complex are studied. The synergistic effect of the enhanced emulsifying ability of chitosan–HOS complexes is shown. The study discloses a possibility to produce an effective bio-compatible emulsifier based on chitosan–HOS complex.

Hydrophobically modified chitosan sponge preparation and its application for anionic dye removal

Via Schiff base reaction, the alkyl chains were grafted to amino groups of chitosan backbone to obtain the hydrophobically modified chitosan (HMCS). The presence of hydrophobic alkyl tails lowers the crystallinity of HMCS but enhances the interaction with hydrophobic adsorbates. HMCS powder exhibited 2-fold higher adsorption capacity (110mgg−1) than chitosan powder toward methyl orange (MO). HMCS can be easily dissolved in mild acid solution and very stable foam was prepared by applying vigorous mechanical stirring to the solution. A robust and non-water wettable sponge was obtained by directly freeze-drying the stable HMCS foam. With enhanced specific surface area, the as-prepared HMCS sponge demonstrated a significantly increased MO adsorption capacity (168mgg−1). The equilibrium adsorption of MO by HMCS sponge follows Langmuir isotherm model and its adsorption kinetic can also be well described by a pseudo-second-order kinetic model.

Non-polar oil assisted DDA flotation of quartz II: Effect of different polarity oil components on the flotation of quartz

It is well accepted that non-polar oils can be used as collector extender in oil agglomeration flotation of many different types of mineral. In this paper, in order to study the influences of oil structures on the non-polar oil assisted dodecylamine (DDA) flotation of quartz, the research focuses on the interaction of DDA (collector) and non-polar oil (collector extender) in aqueous phase. In this work, saturated hydrocarbon dodecane and cyclohexane, unsaturated hydrocarbon dodecene, aromatic hydrocarbon dimethylbenzene and 1-methylnaphthalene were chosen as researched subjects, and the influences of oil structures on interfacial activity of oil–DDA–water ternary models were investigated by experimental and theoretical methods. The flotation results demonstrated that the collecting capability of the oil and DDA combination follows the order of 1-methylnaphthalene>dimethylbenzene>dodecene>cyclohexane>dodecane. Moreover, molecular dynamic (MD) simulation is performed to investigate the interfacial property of these five non-polar oil-DDA-water systems, and five parameters, radial distribution functions, interaction energy, density distribution, interfacial thickness and self-diffusion coefficient are proposed to reveal the influence mechanism of molecular structure on interfacial activity of the ternary oil-DDA-water systems. The same trends are obtained from the parameters described above, aromatic hydrocarbon dimethylbenzene and 1-methylnaphthalene performance better than saturate hydrocarbon and unsaturated hydrocarbon. The researched results indicate the interaction between non-polar oil and DDA hydrophobic alkyl tail would enhance the mobility of oil component, which induce significant change of interfacial thickness and diffusivity. Additionally, the interaction between DDA hydrophilic head group and water molecules via strong hydrogen bonds, van der Waals interactions and weak electrostatic attraction would lead to water molecules penetrate through DDA monolayer and adsorb on oil surface. The researches enable us to obtain a deeper microscopic-level understanding of the interaction between oil-DDA-water ternary components, and maybe have some references for designing of oil-assisted flotation agent.

Composition‐dependent sol‐gel transition of amphiphilic blend of PEG with hydrophobic gallamide components

ABSTRACTTwo types of poly(ethylene glycol) (PEG)‐based amphiphiles were synthesized: a diblock‐type amphiphile (PEG1) with a hydrophobic moiety on one terminal of PEG (PEG with the molecular weight of 2000), and a triblock‐type amphiphile (PEG2) with hydrophobic moieties on both terminals of PEG. The hydrophobic moiety consisted of hydrophobic C14 alkyl tails covalently linked through a gallamide component. The sol–gel transitions of the aqueous solution of PEG1 and PEG2 were studied. At the PEG amphiphile concentration of 15 wt %, PEG1 gave a clear solution over a wide temperature range from 20 to 80 °C, while PEG2 was partially soluble in water. However, the aqueous blend solution of PEG1 and PEG2 exhibited a hydrogel depending on the blend ratio and temperature. It was considered that the composition of PEG1 and PEG2 governed the sol–gel transition, and that the dynamic moduli could be effectively controlled by changing the mixing ratios of the PEG amphiphiles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45402.

Adsorption of Amino Acids and Glutamic Acid-Based Surfactants on Imogolite Clays

Aluminum oxide surfaces are of utmost interest in different biotech applications, in particular for their use as adjuvants (i.e., booster of the immune response against infectious agents in vaccines production). In this framework, imogolite clays combine the chemical flexibility of an exposed alumina surface with 1D nanostructure. This work reports on the interaction between amino acids and imogolite, using turbidimetry, ζ-potential measurements, and Fourier transform infrared spectroscopy as main characterization tools. Amino acids with different side chain functional groups were investigated, showing that glutamic acid (Glu) has the strongest affinity for the imogolite surface. This was exploited to prepare a composite material made of a synthetic surfactant bearing a Glu polar head and a hydrophobic C12 alkyl tail, adsorbed onto the surface of imogolite. The adsorption of a model drug (rhodamine B isothiocyanate) by the hybrid was evaluated both in water and in physiological saline conditions. The findings of this paper suggest that the combination between the glutamate headgroup and imogolite represents a promising platform for the fabrication of hybrid nanostructures with tailored functionalities.

Aqueous Self-Assembly of Y-Shaped Amphiphilic Block Copolymers into Giant Vesicles.

The preparation and aqueous self-assembly of newly Y-shaped amphiphilic block polyurethane (PUG) copolymers are reported here. These amphiphilic copolymers, designed to have two hydrophilic poly(ethylene oxide) (PEO) tails and one hydrophobic alkyl tail via a two-step coupling reaction, can self-assemble into giant unilamellar vesicles (GUVs) (diameter ≥ 1000 nm) with a direct dissolution method in aqueous solution, depending on their Y-shaped structures and initial concentrations. More interesting, the copolymers can self-assemble into various distinct nano-/microstructures, such as spherical micelles, small vesicles, and GUVs, with the increase of their concentrations. The traditional preparation methods of GUVs generally need conventional amphiphilic molecules and additional complicated conditions, such as alternating electrical field, buffer solution, or organic solvent. Therefore, the self-assembly of Y-shaped PUGs with a direct dissolution method in aqueous solution demonstrated in this study supplies a new clue to fabricate GUVs based on the geometric design of amphiphilic polymers.

Preparation and Evaluation of a Novel Class of Amphiphilic Amines as Antitumor Agents and Nanocarriers for Bioactive Molecules

PurposeWe describe a novel class of antitumor amphiphilic amines (RCn) based on a tricyclic amine hydrophilic head and a hydrophobic linear alkyl tail of variable length.MethodsWe tested the lead compound, RC16, for cytotoxicity and mechanism of cell death in several cancer cell lines, anti tumor efficacy in mouse tumor models, and ability to encapsulate chemotherapy drugs.ResultsThese compounds displayed strong cytotoxic activity against cell lines derived from both pediatric and adult cancers. The IC50 of the lead compound, RC16, for normal cells including human keratinocytes, human fibroblasts and human umbilical vein endothelial cells was tenfold higher than for tumor cells. RC16 exhibited significant antitumor effects in vivo using several human xenografts and a metastatic model of murine neuroblastoma by both intravenous and oral administration routes. The amphiphilic character of RC16 triggered a spontaneous molecular self-assembling in water with formation of micelles allowing complexation of Doxorubicin, Etoposide and Paclitaxel. These micelles significantly improved the in vitro antitumor activity of these drugs as the enhancement of their aqueous solubility also improved their biologic availability.ConclusionsRC16 and related amphiphilic amines may be useful as a novel cancer treatment.Electronic supplementary materialThe online version of this article (doi:10.1007/s11095-016-1999-9) contains supplementary material, which is available to authorized users.

Self-assembly of alpha-helical cationic antimicrobial peptide with different length of hydrophobic alkyl tails

Self-assembly of alpha-helical cationic antimicrobial peptide with different length of hydrophobic alkyl tails

Tailoring self-assembly behavior of a biological surfactant by imidazolium-based surfactants with different lengths of hydrophobic alkyl tails

Possible molecular packing model of microcrystal structures formed by NaDC and [C2mim]Br.