Polymerizable Nonionic Surfactant Research Articles

Dispersion of submicron-sized SiO2/Al2O3-coated TiO2 particles and efficient encapsulation via the emulsion copolymerization of methacrylates using a thermoresponsive polymerizable nonionic surfactant

Dispersion of submicron-sized SiO2/Al2O3-coated TiO2 particles and efficient encapsulation via the emulsion copolymerization of methacrylates using a thermoresponsive polymerizable nonionic surfactant

Structural and Physicochemical Properties of a Polymerizable Surfactant Synthesized from N‐Methylol Acrylamide

AbstractA new polymerizable nonionic surfactant with reactive vinyl groups has been synthesized from N‐methylol acrylamide using a two‐step procedure. The structure of the surfactant molecule was characterized by Fourier transform infrared, 1H nuclear magnetic resonance and mass spectroscopy. The surface active properties alongside its self‐assembly properties were investigated by surface tension, electrical conductivity, and fluorescence spectroscopy measurements. As compared with other nonionic surfactants, this study showed that this polymerizable surfactant possesses slightly a higher critical micelle concentration (CMC) value and the surface tension value at CMC. The obtained CMC values were compatible among measurements, ca. 0.02–0.038 M. The evidence of micelle formation also provided by the zeta potential measurements and the obtained zeta potential values showed that the polymerizable surfactant solutions had limited stability. The hydrolysis stability and solubility of the polymerizable surfactant were also investigated. The solubility results have shown that it was soluble in polar solvents while insoluble in nonpolar solvents both at room temperature and 40 °C. The acidic and basic hydrolysis of the surfactant increased as the temperature increased and the hydrolysis stability was 180 min (basic medium) and 55 min (acidic medium) at 80 °C.

Novel Polymerizable Nonionic Surfactants (Surfmers) Corporate with Alkenylsuccinic Anhydride: Synthesis, Surface, and Thermodynamic Properties

In this article, nine polymerizable surfactants (surfmers) were prepared with terminal acrylate group on the hydrophilic moiety. The prepared surfmers were classified into three groups according to hydrophobic chain lengths; the first group (group I) was single-tailed with different hydrophobic chain lengths, the second group (group II) was asymmetric double-tailed, one of them was dodecenyl and the other is octyl or tetradecyl or octadecyl from fatty alcohols, and the third group (group III) is symmetric double-tailed. The chemical structures of the prepared nonionic surfmers were confirmed by mass spectra, elemental analysis, acid value titration, and FTIR and 1H NMR spectroscopy. The surface and thermodynamic parameters of the prepared surfmers were determined at 25°C including, surface tension (γ) and effectiveness, maximum surface excess (Γmax) and minimum surface area (Amin). Also, the standard free energy of micellization and adsorption were recorded. The results show that the surface and thermodynamic parameters of the prepared surfmers were sensitive to the discrepancy of surfmer tail length and their expected shape on the interface.

One-pot synthesis of amphiphilic reversible photoswitchable fluorescent nanoparticles and their fluorescence modulation properties

In the present study, we report on the fabrication of novel amphiphilic reversible photoswitchable fluorescent nanoparticles by a facile one-pot miniemulsion polymerization using a biocompatible polymerizable nonionic surfactant, ω-methoxy poly(ethylene oxide) undecyl α-methacrylate (PEO-R-MA-40), in which spiropyran-linked methacrylate (SPMA) and the energy level well-matched fluorescent dyes: fluorescein-based, vinylic crosslinking monomer (fluorescein-O,O-bis-propene (FBP)) were covalently incorporated into polymeric matrix during the polymerization process. Under the alternative irradiation of UV and visible light, the fluorescent emission of FBP dye in nanoparticles can be reversibly modulated by cyclical transformation of spiropyran moieties' structure on the basis of intra-particle FRET process between FBP and merocyanine (MC) state of spiropyran. The as-prepared fluorescent nanoparticles display high dye load, as well as controllable amount and ratio of the two dyes because of covalent linkage between dye molecules and the particle. Moreover, the observed FRET efficiencies (66.3–98.5%) can be facilely tuned by controlling the amount (ratio) of the two chromophores. Overall, significant features of these novel amphiphilic reversible photoswitchable fluorescent nanoparticles include higher biocompatibility and photostability, relatively fast photoresponsivity and better photoreversibility as compared to some previous reported systems, which are promising for biological, optical fields and so on.

Synthesis and Characterization of Polymerizable Nonionic Surfactants

Synthesis and Characterization of Polymerizable Nonionic Surfactants

Synthetic myelin figures immobilized in polymer gels.

Myelin-like instabilities usually form from the interface of amphiphilic lamellar phases and solvent, and resemble the neuron-like structures in nerve systems. However, these myelin structures are thermodynamically unstable. We herein present our first success in synthesizing stable myelin figures separated organized-polymerization. Myelin figures formed with a polymerizable nonionic surfactant have been immobilized in polymer gels. The results obtained from confocal laser scanning microscopy (CLSM), small angle X-ray scattering (SASX) and freeze fracture transmission electron microscopy (FF-TEM) clearly prove that the myelin structures have been well immobilized without any structural change. The immobilized myelin structures in polymer gels were kept for 6 months and no obvious change was observed in their structures and/or shapes. The success in stabilizing these unstable myelin structures provides some potential for applications, such as anisotropic gels, electrophoresis mediums for the separation of hydrophobic materials and so on.

Fabrication and Characterization of Nanostructured and Thermosensitive Polymer Membranes for Wound Healing and Cell Grafting

AbstractNanostructured, transparent, and thermosensitive membranes synthesized by bicontinuous microemulsion polymerization of N‐isopropylacrylamide (NIPAAm), methyl methacrylate (MMA), and 2‐hydroxyethyl methacrylate (HEMA) using a polymerizable nonionic surfactant, ω‐methoxy poly(ethylene oxide)40 undecyl α‐methacrylate macromonomer have recently been reported. In this study, the synthesis and characterization of membranes with various compositions are presented in detail, focusing on the effects of environmental temperature and membrane composition on surface hydrophilicity, cell attachment, and detachment. The membranes synthesized with differing compositions have a nanoporous structure, and are transparent and thermosensitive in their swelling ratio and cell‐attachment characteristics. Decreasing the environmental temperature and the MMA content leads to an increase in the wettability of the membrane surface. In addition, both L929 murine neoplastic fibroblasts and primary human dermal fibroblasts can attach to and detach from the membranes with varying temperature. High cell‐attachment and ‐detachment efficiencies are achieved by optimizing membrane composition and environmental temperature. In addition, the membranes do not show significant cytotoxicity. These membranes have great potential for the construction of a new generation of dressings and cell‐delivery systems for wound healing.

Synthesis of polymer particles and nanocapsules stabilized with PEO/PPO containing polymerizable surfactants in miniemulsion

We describe the miniemulsion polymerization of vinyl monomers stabilized in the presence of the polymerizable anionic surfactant Tego XP-1008 and the polymerizable nonionic surfactant Tego XP-1007. Different amounts of polymerizable surfactants and various types of initiators were used to investigate the size and the stability of the final latex particles by transmission electron microscopy and dynamic light-scattering measurements. The grafting of the polymerizable surfactants onto the surface of the latex particles was checked by NMR and XPS measurements and was found to be efficient. Finally, polymerizations of appropriate formulations containing divinylbenzene with the polymerizable surfactant Tego XP-1008 in the presence of a larger amount of hydrophobic agent produced nanocapsules.

Nanofiltration membranes prepared by direct microemulsion copolymerization using poly(ethylene oxide) macromonomer as a polymerizable surfactant

A novel polymer membrane with nanosized pore structures has been prepared from the direct copolymerization of acrylonitrile (AN) with a polymerizable nonionic surfactant in water-in-oil (w/o) or bicontinuous microemulsions. This polymerizable surfactant is ω-methoxy poly(ethylene oxide)40 undecyl-α-methacrylate macromonomer [CH3O(CH2CH2O)40(CH2)11OCO(CH3)CCH2, abbreviated: C1-PEO-C11-MA-40]. Besides PEO macromonomer, AN, and crosslinker ethyleneglycol dimethacrylate, the microemulsion system contained varying amount of water that formed w/o microemulsions having water droplet structures and bicontinuous microemulsions consisting of interconnected water channel. The polymerized membranes prepared in this study have pore radii ranging from 0.38 to 2.4 nm as evaluated by PEG filtration. The pore size appears to vary linearly with water content in precursor microemulsions. But a sharp change in the gradient of the linear relationship is observed around 25 wt % water content. Membranes made from bicontinuous (>25 wt % water) microemulsion polymerization have a larger and interconnected (open-cell) nanostructures. In contrast, much smaller closed-cell (disinterconnected) nanostructures were obtained from w/o (<25 wt % water) microemulsion polymerization and the membrane exhibited a permselectivity toward water in pervaporation separation of high ethanol (>50 wt %) aqueous solutions. The separation factor (α) for 95% ethanol aqueous solution by the membrane derived from the microemulsion containing 10 wt % water is about 20. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2785–2794, 2000

Nanofiltration membranes prepared by direct microemulsion copolymerization using poly(ethylene oxide) macromonomer as a polymerizable surfactant

A novel polymer membrane with nanosized pore structures has been prepared from the direct copolymerization of acrylonitrile (AN) with a polymerizable nonionic surfactant in water-in-oil (w/o) or bicontinuous microemulsions. This polymerizable surfactant is ω-methoxy poly(ethylene oxide)40 undecyl-α-methacrylate macromonomer [CH3O(CH2CH2O)40(CH2)11OCO(CH3)CCH2, abbreviated: C1-PEO-C11-MA-40]. Besides PEO macromonomer, AN, and crosslinker ethyleneglycol dimethacrylate, the microemulsion system contained varying amount of water that formed w/o microemulsions having water droplet structures and bicontinuous microemulsions consisting of interconnected water channel. The polymerized membranes prepared in this study have pore radii ranging from 0.38 to 2.4 nm as evaluated by PEG filtration. The pore size appears to vary linearly with water content in precursor microemulsions. But a sharp change in the gradient of the linear relationship is observed around 25 wt % water content. Membranes made from bicontinuous (>25 wt % water) microemulsion polymerization have a larger and interconnected (open-cell) nanostructures. In contrast, much smaller closed-cell (disinterconnected) nanostructures were obtained from w/o ( 50 wt %) aqueous solutions. The separation factor (α) for 95% ethanol aqueous solution by the membrane derived from the microemulsion containing 10 wt % water is about 20. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2785–2794, 2000

Nanostructured Polymeric Materials from Microemulsion Polymerization Using Poly(ethylene oxide) Macromonomer

Transparent nanostructured polymeric materials have been produced from the direct polymerization of bicontinuous microemulsions using the macromonomer ω-methoxy−poly(ethylene oxide)40−undecyl−α-methacrylate (C1−PEO−C11−MA-40) as a polymerizable nonionic surfactant. Besides the PEO macromonomer, the system also consisted of methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), water, and the cross-linker ethylene glycol dimethacrylate (EGDMA). Most of the bicontinuous microemulsions investigated could be gelled within 10 min at 30 °C using a redox initiator. The transparent microemulsions were eventually transformed to transparent solid polymers. These polymeric materials were characterized by thermoporometry, SEM observation, and the pore size evaluation for the polymer films by PEG filtration. The pore size of these transparent polymeric materials ranges from about 1 to 10 nm in diameter. It was larger for the systems containing higher ratios of water to HEMA or water to C1−PEO−C11−MA-40 and smaller for higher ratios of HEMA to C1−PEO−C11−MA-40. The results from PEG filtration provide the direct evidence that bicontinuous nanostructured polymeric materials can readily be prepared via the polymerization of these nonionic bicontinuous microemulsions.

Acrylic Latices Stabilized by Polymerizable Non-ionic Surfactant

The final latex particle size is controlled by the concentration of polymerizable non-ionic surfactant NE-40 in the emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA). The particle size decreases with increasing NE-40 concentration and increases with increasing persulphate initiator concentration. The dependence of particle size on the initiator concentration does not follow conventional Smith–Ewart theory, which is attributed to the bridging flocculation process during the particle nucleation period. The differences in the particle nucleation and growth stages and colloidal stability observed in the NE-40 and nonyl phenol-40 mol ethylene oxide adduct (NP-40) stabilized systems can be attributed to the different distribution patterns of surfactant molecules in the particles. Experimental data also indicate that the particle size decreases with increasing electrolyte concentration, or agitation speed. The total scrap, presumably caused by the bridging flocculation process, increases rapidly with increase in the NaCl concentration The amount of large flocs formed during polymerization is generally greater for the run operated at higher agitation speed. As expected, the latex products stabilized by non-ionic surfactants show excellent stability toward added sodium salt.

Synthesis and Polymerization of a Nonionic Surfactant: Poly(Ethylene Oxide) Macromonomer

Abstract A polymerizable nonionic surfactant macromonomer, ω-methoxy poly(ethylene oxide)nundecyl-α-methacrylate (n = 40) has been synthesized from poly(ethylene glycol) methyl ether, 11-bromoundecanol, and methacryloyl chloride. The critical micelle concentration of the macro-monomer is 6.6 × 10−5 mol/L at 25°C. The kinetics of its polymerization in aqueous medium follows conventional solution polymerization, i.e., first and half order with respect to the concentrations of the macro-monomer and K2S2O8, respectively. The rate of its polymerization in water was extremely rapid (within 30 minutes) as compared to its solution polymerization in benzene (days). The activation energies for the macromonomer polymerization were 57 kJ/mol in water but 179 kJ/mol in benzene. The aqueous system produced polymers with a number-average degree of polymerization (DPn) ranging from about 130 to 160, but it was much lower (DPn ≐ 7) for the benzene system. The possible micellar polymerization mechanism for the macromonomer...

Alkyd emulsions

Various aspects of alkyd emulsion technology have been investigated. The influence of alkyd oil length, acid value and hydroxyl number and type of surfactant used as emulsifier, on shear stability of alkyds emulsions have been studied. It was found that the acid value was the most important alkyd parameter, the stability increasing with increasing oil length. It is also shown that anionic surfactants give emulsions with small droplet sizes at lower concentrations than do nonionics. Polymerizable nonionic surfactants have been tested as emulsifiers and compared with conventional surfactants of the same hydrophilic lipophilic balance (HLB). It was found that surfactants capable of participating in the autoridative curing process give faster drying and improved film hardness compared with nonreactive surfactants. The distribution of driers between the alkyd phase and the water phase has been investigated. It was found that low pH and the use of hydrophilic anionic surfactants, such as sodium dodecyl sulphate, favour partitioning of cobalt into the aqueous phase which is unfavourable with respect to drying properties.