Hydrophilic Ethylene Research Articles

Water hydration of polyethylene glycol dimethyl ether.

In this work, GHz and THz complex dielectric spectra of a polyethylene glycol dimethyl ether (2000 g/mol) aqueous solution were studied. The reorientation relaxation of water in this kind of macro-amphiphilic molecule solution can be well described by three Debye models, including under-coordinated water, bulk-like water [water molecules in a tetrahedral hydrogen bond network (bulk water) and bulk water molecules affected by hydrophobic groups], and slow hydrating water (water molecules donating hydrogen bonds to hydrophilic ether groups). The reorientation relaxation timescales of bulk-like water and slow hydration water both show increases with concentration from 9.8 to 26.7ps and from 46.9 to 100.1ps, respectively. By estimating the ratios of the dipole moment of slow hydration water to the dipole moment of bulk-like water, we calculated the experimental Kirkwood factors of bulk-like and slow hydrating water. The experimental Kirkwood factor of bulk-like water increased from 3.17 to 3.44 with concentrations, while the experimental Kirkwood factor of slow hydrating water roughly remained constant at 4.13 from concentrations of 15%-60%. The estimated water molecule numbers of three water components around monomers also confirm our sorting for water components.

1,2,3,5-Tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN)-based porous organic polymers for visible-light-driven organic transformations in water under aerobic oxidation

A series of hyper-crosslinked POPs were constructed by Friedel–Crafts alkylation reaction of 4CzIPN with FDA, which contains a certain quantity of hydrophilic ether residues to facilitate visible-light-promoted aqueous organic transformations.

Effects of Heterogeneous Linear Polyether Segments on the Membrane Breathability of Nonionic Polyurethane

Characterizing the relationships between the water repellency and moisture permeability (breathability) of hydrophilic polyurethane and its supramolecular structure, including the phase inversion temperature in the soft phase, is unavoidable when developing intelligent, breathable textile products. In this study, a two-step technique was employed to prepare hydrophilic nonionic polyurethanes (PU) with various polyether (PE) soft segments. The hard segments of the samples were composed of 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO), while the soft segments consisted of polyethylene glycol 1000 (PEG), polytetramethylene glycol 1000 (PTMG), or their mixture. The relationships between the chemical and physical structure and the breathability were studied. The results showed that the samples with better separated structure between the soft and hard domains had a special microstructure of partial compatibility and simultaneously partial separation between the polyether soft and hard domains. In addition, the distribution of the mixed polyethers in the soft domains was homogeneous. The microphase structure, especially the hydrophilic ether bond content, exhibited a specific corresponding relevancy to the water resistance, moisture permeability and hydrophilicity of the PU membrane. The moisture permeability and water resistance were also directly related to their film-forming properties. Enhanced microphase separation intensified the positive effects of ether bonds on the moisture permeability, while worsened microphase separation weakened their negative influence on the water resistance/hydrophobicity.

Flexibly crosslinked and post-morpholinium-functionalized poly(2,6-dimethyl-1,4-phenylene oxide) anion exchange membranes

Morpholinium-functionalized cross-linked poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) anion exchange membranes were prepared using a crosslinking/post-functionalization method. 4,4'-(oxybis(ethane-2,1-diyl)) dimorpholine (OEDM) having a flexible long chain and hydrophilic ether bond was for the first time used as the crosslinker. The brominated PPO reacted with OEDM, forming a crosslinked structure and accomplishing partial functionalization. Further functionalization was carried out by immersion in N-methylmorpholine aqueous solution. The degree of crosslinking was controlled by varying the proportion of brominated PPO to OEDM because excessive bromomethyl groups ensured the occurrence of crosslinking reaction. The cross-linked structure promoted the formation of micro-phase separation and effectively limited swelling. The crosslinked membrane shows much higher conductivity and lower swelling ratio compared to non-crosslinked one at similar IEC. The highest hydroxide conductivity that the crosslinked membrane achieves is 35 mS cm−1 at 20 °C. The power density for the H2/O2 single cell assembled with this membrane is up to 193 mW cm−2. In addition, the crosslinked PPO-MmOH-Cr membrane exhibits good alkaline stability with conductivity loss of less than 15% after soaking in 1 M KOH for 96 h.

Further Understanding of the Reactivity Control of Bisphosphonates to a Metal Source for Fabricating Highly Ordered Mesoporous Films.

Mesoporous metal organophosphonates having embedded organic functions are a promising platform to hybridize organics and non-siliceous inorganic frameworks in their molecular scale. However, the reactivity between a bisphosphonate and a metal source is dramatically different for their combination and then hampers to construct ordered mesoporous structures even when using amphiphilic organic molecules. By proposing an advanced method to adjust such reactivity, we recently succeeded in fabricating ordered mesoporous aluminum organophosphonate (AOP) films with chemically designable benzene units inside their hybrid frameworks. The reactivity of the organically bridged bisphosphonates has been controlled by utilizing dissimilar reactivities of acid-base pairs like P-OH and P-OEt groups to AlCl3 . Here, we further prove our reactivity-control concept through the introduction of organic groups, such as those having symmetric thiophene, asymmetric amide, and hydrophilic ether units. Liquid-state 31 P NMR measurements further clarified the usefulness of the control of the -OH/ -OEt ratio in the same bisphosphonate molecules for obtaining highly ordered mesostructured AOP films.

Facilitated water-selective permeation via PEGylation of graphene oxide membrane

Manipulating the chemical structure of GO interlayer channels is an efficient strategy to improve the selective molecular transport through the resultant GO membrane. In this work, PEGylation of GO membrane was performed to incorporate hydrophilic ether bonds into the interlayer channels in GO membrane for efficient separation of ethanol and water mixtures via pervaporation. Poly(ethylene glycol) diamines (PEGDA) was adopted as the intercalation molecule to covalently bond with GO through the reaction between amine and epoxy groups. Numerous ether bonds increase membrane hydrophilicity and promote water adsorption, while the covalent cross-linking confers the membrane robustness for operation, thus achieving an increase in separation factor and stability. On this basis, highly hydrophilic sodium alginate (SA) was then coated on the surface of PEGDA-GO composite membrane to further strengthen the adsorption of water molecules on the membrane surface. Compared with pristine graphene, the SA/PEGDA-GO membrane shows a concurrent enhancement in the permeation flux and separation factor. The sodium alginate coated PEGylated GO composite membrane possesses an exceptional pervaporation performance with the permeation flux of 3595 g m−2 h−1 and water purity in permeate of 98.5% under the conditions of 70 °C and water concentration in feed of 20 wt%. The membrane performance remains stable during a long-term operation test for 120 h at 70 °C.

Synthesis and characterization of alicyclic two-component waterborne polyurethane

PurposeThe purpose of this paper is to synthesize and characterize a series of alicyclic two-component waterborne polyurethane (2K-WPU) which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion.Design/methodology/approachThe appearances of aqueous dispersions and 2K-WPU films were observed by photographs. The micromorphology of alicyclic polyisocyanate aqueous dispersion was examined by scanning electron microscopy (SEM). The molecule structures of WPU were studied by Fourier transform infrared (FTIR). The effect of NCO:OH molar ratio of two components and trimethylolpropane (TMP) content on the thermal stability, mechanical and water resistance properties of 2K-WPU films was studied.FindingsIt was found by SEM that alicyclic polyisocyanate particles in aqueous dispersion showed a kind of spherical particle appearance, in which hydrophobic polyisocyanate was encapsulated by hydrophilic ether linkages segment. FTIR showed that WPU was polymerized through mixture of polyisocyanate component and hydroxyl component and increasing NCO:OH molar ratio of two components from 1.1:1 to 1.5:1 had increased the content of urea, urethane and allophanate of 2K-WPU films. Increasing NCO:OH molar ratio had improved the mechanical and thermal properties of the 2K-WPU film, but the water resistance of the 2K-WPU film increased first and then weakened. Increasing TMP contents from 1 to 0.75 mol for 1:5 system had improved the mechanical, thermal and water resistance properties of the 2K-WPU film.Practical implicationsThe investigation established a method to prepare alicyclic 2K-WPU which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. The prepared 2K-WPU film could be applied in the field of waterborne surface coating, e.g. textile, wood and synthetic leather surfaces (Hasan et al., 2017; Akindoyo et al., 2016).Originality/valueThe paper established a method to synthesize alicyclic two-component 2K-WPU. The effect of NCO:OH molar ratio and TMP content on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

Synthesis, characterization and antifouling performance of ABC-type fluorinated amphiphilic triblock copolymer

In this paper, a series of ABC-type fluorinated amphiphilic triblock copolymer composed of hydrophilic block (PEG block), hydrophobic “anchoring” block (poly(methyl methacrylate) (PMMA) block), and nonpolar hydrophobic block (poly(2-perfluorooctylethyl methacrylate) (PFMA) block) were prepared by atom transfer radical polymerization and characterized. By manipulating the bulk composition and annealing treatment, the films with various surface compositions were prepared and then the adsorption behaviors of human plasma fibrinogen (HFg) and bacterial (Escherichia coli) adhesion on these surfaces were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The antifouling performances of the amphiphilic triblock copolymers after incorporation of fluorinated block are enhanced compared to PMMA-b-PEG and homopolymer PMMA. The surface compositional heterogeneities with special content of hydrophilic and fluorinated moieties play a significant role in antifouling properties. When the percentage of hydrophobic fluorinated moieties is 21 % and the percentage of hydrophilic ether group is 9.5 % on the surface, the copolymer surface is most unfavorable for protein adsorption. The bacterial adhesion experiment shows the similar results. These results demonstrate the desirable antifouling performance from the ABC-type fluorinated amphiphilic triblock copolymers and provide further realization of the effect of amphiphilic surface structures on the protein adsorption and bacterial adhesion behavior.

Hydrophilicity as a measure of the efficiency of the superplasticisers

This paper presents the results of chemical structural investigations of four new-generation superplasticizers (denoted here as SP-A through SP-M2) used in concrete production engineering. The commercial product samples, the gel permeation chromatography (GPC) and the Fourier-Transformed Infrared Spectroscopy (FTIR) test methods were applied to the research. The effect of superplasticizers on the rheological properties of cement pastes was tested. The performance of a superplasticizer, i.e. the reduction of plastic viscosity, was demonstrated to be enhanced by: hydrophilicity of the SP polymer –understood as the ratio of hydrophilic ethers to hydrophobic esters in the polymer chain, SP polymer content in the bulk of the commercial product sample, weight-average molecular weight (Mw) of the SP polymer. The above relations were confirmed for the studied superplasticizers– the derivatives of: acrylic acid (SP-A1 and SP-A2) and maleic acid (SP-M2 and SP-M1). The efficiency of superplasticizers was found to decrease with the contents of the free poly(ethylene glycols) (PEGs) which remained unreacted with acids and/or anhydride. The superplasticizers based on the maleic anhydride derivatives (SP-C and SP-D) proved to be more efficient and to slow down the hydration process to a much higher extent than the superplasticizers – acrylic acid derivatives (SP-A1 and SP-A2).

Behavior of organophosphates and hydrophilic ethers during bank filtration and their potential application as organic tracers. A field study from the Oderbruch, Germany

The behavior of organophosphates and ethers during riverbank filtration and groundwater flow was assessed to determine their suitability as organic tracers. Four sampling campaigns were conducted at the Oderbruch polder, Germany to establish the presence of chlorinated flame retardants (TCEP, TCPP, TDCP), non-chlorinated plasticizers (TBEP, TiBP, TnBP), and hydrophilic ethers (1,4-dioxane, monoglyme, diglyme, triglyme, tetraglyme) in the Oder River, main drainage ditch, and anoxic aquifer. Selected parameters were measured in order to determine the hydro-chemical composition of both, river water and groundwater. The results of the study confirm that organophosphates (OPs) are more readily attenuated during bank filtration compared to ethers. Both in the river and the groundwater, TCPP was the most abundant OP with concentrations in the main drainage ditch ranging between 105 and 958ngL−1. 1,4-dioxane, triglyme, and tetraglyme demonstrated persistent behavior during bank filtration and in the anoxic groundwater. In the drainage ditch concentrations of 1,4-dioxane, triglyme, and tetraglyme ranged between 1090 and 1467ngL−1, 37 and 149ngL−1, and 496 and 1403ngL−1, respectively. A positive correlation was found for the inorganic tracer chloride with 1,4-dioxane and tetraglyme. These results confirm the possible application of these ethers as environmental organic tracers. Both inorganic and organic compounds showed temporal variability in the surface- and groundwater. Discharge of the river water, concentrations of analytes at the time of infiltration and attenuation were identified as factors influencing the variable amounts of the analytes in the surface and groundwater. These findings are also of great importance for the production of drinking water via bank filtration and natural and artificial groundwater recharge as the physicochemical properties of ethers create challenges in their removal.

Sequential deposition of hexamethyldisiloxane and benzene in non-thermal plasma adhesion to dental ceramic

According to the types of dental ceramic, various surface treatment techniques have been tried for adhesive cementation, but each treatment has its shortcomings. A simple and universal surface treatment for intraoral and chair-side adhesion promotion is needed for resin cements. This study investigated whether hexamethyldisiloxane (HMDSO) and benzene, when deposited using a low-power non-thermal atmospheric pressure dielectric barrier discharge jet, were effective precursor monomers in dental ceramic adhesion. Their effect on adhesion was evaluated with shear bond strength test (SBS), contact angle measurement, X-ray photoelectron spectroscopy, and Fourier transform infra-red spectrophotometer in an attenuated total reflectance mode. The bonded interfaces and fractured surfaces were evaluated using a scanning electron microscope. Plasma polymerization of HMDSO resulted in formation of a siloxane network (Si2 peak), but its surface hydrophobicity hindered adhesive wetting. Additional deposition of benzene onto the HMDSO-coated ceramic surface increased the C1 peak, which partly corresponded to the C=C double bonds, and the hydrophilic peaks (C-O, C=O and O-C=O bonds). Benzene deposition itself improved the adhesion between the ceramic and the overlying adhesive through the chemical interaction of C=C double bonds and the increased hydrophilic groups. Additional deposition of HMDSO before benzene mediated the chemical adhesion of benzene to the ceramic surface and led to an additional increase of bond strength. Plasma polymerization of benzene and HMDSO/benzene increased the bond strength of composite resin to dental ceramic by improving wettability and adaptation with hydrophilic ether, carbonyl and ester groups, and chemical bonding with active species, such as C=C double bonds and silanol groups. Open image in new window

Simultaneous determination of six hydrophilic ethers at trace levels using coconut charcoal adsorbent and gas chromatography/mass spectrometry

The main objective of the following study was to determine the efficiency of a method that uses coconut charcoal as a solid-phase extraction (SPE) adsorbent in order to simultaneously detect six hydrophilic ether species in water in the low microgram-per-liter range. The applied method was validated for quantification of ethyl tert-butyl ether, 1,4-dioxane, ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme) and tetraethylene glycol dimethyl ether (tetraglyme). SPE followed by gas chromatography/mass spectrometry of the extracts using the selected ion monitoring mode allowed for establishing low detection limits in the range of 0.007-0.018 μg/L in ultrapure water and 0.004-0.020 μg/L in environmental samples. Examination of the method accuracy and precision resulted in a recovery greater than 86.8 % for each compound with a relative standard deviation of less than 6.6 %. A stability study established a 5-day holding time for the unpreserved water samples and extracts. Finally, 27 samples obtained from surface water bodies in Germany were analyzed for the six hydrophilic ethers. Each analyte was detected in at least eight samples at concentrations reaching 2.0 μg/L. The results of this study emphasize the advantage of the method to simultaneously determine six hydrophilic ether compounds. The outcome of the surface water analyses augments a concern about their frequent and significant presence in surface water bodies in Germany.

Solvent-Driven Room-Temperature Synthesis of Nanoparticles BiPO4:Eu3+

In this work, a novel solvent-driven room-temperature synthesis of BiPO(4):Eu(3+) nanoparticles was presented. By virtue of 11 solvents with different properties and function groups, phase structure and composition of BiPO(4):Eu(3+) can be systematically tailored. Hexagonal phase (HP) of BiPO(4):Eu(3+) was obtained in water and hydrophobic organic solvents such as arenes and cyclohexane, while low-temperature monoclinic phase (LTMP) was prepared in hydrophilic alcohols. In other solvents (i.e., hydrophilic ethers, aldehydes, ketones, and carboxylic acids), a mixture of HP and LTMP was formed, in which the relative content of LTMP gradually increased following the above solvent sequence. It is also found that particle sizes of BiPO(4):Eu(3+) nanoparticles were closely related to the phase structure: HP exhibited a comparatively larger particle size. The phase evolution processes for both polymorphs with varying solvents were investigated in details. Photoluminescence (PL) properties were sensitive to the phase structure and compositions of the final products. With increasing the phase content of LTMP, the lifetimes and quantum yields both increased. The methodology reported here is fundamentally important, which may give a novel insight into the polymorph-controlled synthesis for further optimized materials performance.

Influences of Soft Monomers on the Application Properties of Hydrophilic Polyurethane with Mixed Polyether Segment

A series of hydrophilic polyether polyurethanes were prepared with two-steps technique from 4,4’- diphenylmethane diisocyanate (MDI), polytetramethylene glycol 1000 (PTMG1000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Further more, the relationships between structure and moisture permeability, water resistance, hydrophility and phase inversion temperature (PIT) of the polyurethanes was investigated. For polyether polyurethanes with nicer micro phase separation structure, the studies show that the hydrophilic ether bond content and mobility of soft segment chains have decisive effect on their water resistance, moisture permeability and hydrophility without reference to the soft segment content on the whole.

Effects of soft monomers on the water resistance and moisture permeability of hydrophilic polyurethane

Six groups of segmented polyurethanes with amorphous soft segment domains based on mixed hydrophobic polyester and hydrophilic polyether soft monomers were prepared from 4, 4′-diphenylmethane diisocyanate (MDI), polybutylene adipate glycol 2000 (PBA2000), polytetramethylene glycol 1000 (PTMG1000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Furthermore, the representative properties of the hydrophilic polyurethanes, moisture permeability and water resistance, were investigated. The results show that the chemical structure, molecular weight and concentration of soft monomers have remarkable effects on the main application properties of hydrophilic polyurethane. The important factors in diffusion are the content of hydrophilic ether bond and the mobility of hydrophilic chain in the soft phase, which is represented with a good approximation by the average mean molecular weight of soft segment. On the contrary, the functional properties of the hydrophilic polyurethane are almost not affected by its hard segment.

Adsorption of poly(ethylene oxide) on smectite: Effect of layer charge

The adsorption of polymers on clay is important in many applications. However the mechanisms of poly(ethylene oxide) (PEO) adsorption on smectite is not well elucidated at present. The aim of this study was to investigate the effect of layer charge density on the adsorption of PEO by smectite. The results indicated that both the hydrophobic interaction (between CH 2 CH 2 groups and siloxane surface) and the hydrogen bonding (between ether oxygen of PEO and structure OH of smectite) lead to PEO preferential adsorption on the surface of low-charge smectite. In addition, the delamination of low-charge smectite in water is enhanced upon PEO adsorption presumably due to the hydrophilic ether oxygen of adsorbed PEO.

Influence of soft segments on thermal and mechanical properties of terpoly(ester-ether-ester)s

The aim of the work was preparation and investigation of new multiblock terpoly(ester-ether-ester)s (TEEE) containing phthalic acid units as in poly(butylene terephthalate) (PBT) (hard segments) and hydrogenated dimer of dilinoleic acid called as dilinoleic acid sequences (DLA) as hydrophobic ester soft segments, and poly(ethylene glycol) (PEG) as hydrophilic ether soft segments. PEG of different molecular weight (1000 and 4600) was used. Synthesis was performed in a presence of α-tocopherol as non-toxic thermal stabilizer since these materials are targeted for biomedical applications. In this paper, the influence of amount and molecular weight of PEG on thermal and mechanical properties of TEEE is discussed.

Phase Separation of Poly(vinyl methyl ether) Aqueous Solution: A Near-Infrared Spectroscopic Study

The thermosensitive phase separation of poly(vinyl methyl ether) (PVME) aqueous solutions has been investigated using near-infrared spectroscopy in combination with two-dimensional correlation analysis, and a two-step phase separation mechanism during gradual heating has been established. Two-dimensional near-infrared (2D NIR) analysis results indicate that during this two-step process the dehydration of CH 2 groups occurs earlier than that of CH 3 groups. This result suggests that it is the change of the hydrophobic hydrocarbon chain conformation induced by heating that indirectly leads to the dehydration of the hydrophilic ether oxygen side groups.

Effects of poly(ethylene oxide) adsorption on the dispersion of smectites

The adsorption of polymers on clay is important in many applications. However the mechanisms of poly(ethylene oxide) (PEO) adsorption on smectite and its effect on suspension rheology are not well elucidated at present. The aim of this study was to investigate the mechanisms responsible for PEO sorption on smectite and how this impacts on dispersive behavior of smectite suspension. The results indicated that the hydrophobic interaction between CH 2 CH 2 groups and siloxane surface is the major driven force for PEO adsorption on smectite. In addition, PEO adsorbed preferentially on the surface of low-charge smectite and the delamination of low-charge smectite in water was enhanced due to PEO adsorption presumably due to the hydrophilic ether oxygen of adsorbed PEO.

Novel thromboresistant materials

The development of a clinically durable small-diameter vascular graft as well as permanently implantable biosensors and artificial organ systems that interface with blood, including the artificial heart, kidney, liver, and lung, remain limited by surface-induced thrombotic responses. Recent breakthroughs in materials science, along with a growing understanding of the molecular events that underlay thrombosis, has led to the design and clinical evaluation of a variety of biologically active coatings that inhibit components of the coagulation pathway and platelet responses by surface immobilization or controlled release of bioactive agents. This report reviews recent progress in generating synthetic thromboresistant surfaces that inhibit (1) protein and cell adsorption, (2) thrombin and fibrin formation, and (3) platelet activation and aggregation.