• Macromolecular Research
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• v.13 no.5
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• pp.385-390
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• 2005

The electrospinning process is a fascinating method to fabricate small nanosized fibers of diameter several hundred nanometers. Surfactant-polymer solutions were prepared by adding poly(vinyl alcohol) (PVOH) to distilled water with cationic, anionic, amphoteric, and non-ionic surfactants. Average diameter of the electrospun PVOH fibers prepared from PVOH solution was over 300 nm, and was decreased to 150 nm for the mixture of PVOH/amphoteric surfactant. To explain the formation of ultra fine fiber, the characteristic properties in a mixture of PVOH/surfactant such as surface tension, viscosity, and conductivity were determined. In this paper, the effect of interactions between polymers with different classes of surfactants on the morphological and mechanical properties of electrospun PVOH nonwoven mats was broadly investigated.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.160-166
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• 2007

The rheological properties and surface tensions of polymer solutions and polymer-surfactant mixed solutions were investigated. The polymers used in this study were a homopolymer of acrylic acid crosslinked with an allyl ether of pentaerythritol, an allyl ether of sucrose, or an allyl ether of propylene (CARBOMER), acylate/C10-30 alkyl acylate crosspolymer (AAAC), and ammonium acryloydimethyltaurate/VP copolymer (ADTV). A solubilizing agent PEG-40 hydrogenated castor oil (HCO-40) and an emulsifying agent polyoxyethylene (20) sorbitan monostearate (POLYSORBATE 60) made the micelles intervening between AAAC polymers, resulting in the increase of viscosity. However, HCO-40 made this behavior over the wider range of surfactant concentration than POLYSORBATE 60. From the view point of surface tensions in the same range of surfactant concentration, AAAC/HCO-40 solution showed the area of increasing surface tension with surfactant concentration in contrast to the AAAC/POLYSORBATE 60 solution showing no increasing area.

• Korea-Australia Rheology Journal
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• v.14 no.1
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• pp.1-9
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• 2002

Steady and dynamic shear properties of two hydrophobically modified alkali soluble emulsions (HASE), NPJI and NPJ2, were experimentally investigated. At the same polymer concentration, NPJ1 is appreciably more viscous and elastic than NPJ2. The high hydrophobicity of NPJ1 allows hydrophobic associations and more junction sites to be created, leading to the formation of a network structure. Under shear deformation, NPJ1 exhibits shear-thinning behaviour as compared with Newtonian characteristics of NPJ2. NPJ1 and NPJ2 exhibit a very high and a low level of elasticity respectively over the frequency range tested. For NPJ1, a crossover frequency appears, which is shifted to lower frequencies and hence, longer relaxation times, as concentration increases. Three different surfactants anionic SDS, cationic CTAB, and non-ionic TX-100 were employed to examine the effects of surfactants on the rheology of HASE. Due to the different ionic behaviour of the surfactant, each type of surfactant imposed different electrostatic interactions on the two HASE polymers. In general, at low surfactant concentration, a gradual increase in viscosity is observed until a maximum is reached, beyond which a continuous reduction of viscosity ensues. Viscosity development is a combined result of HASE-surfactant interactions, accompanied by constant rearrangement of the hydrophobic associative junctions, and electrostatic interactions.

• Korea-Australia Rheology Journal
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• v.14 no.4
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• pp.189-201
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• 2002

The interaction between hydrophobically modified hydroxyethyl cellulose (hmHEC), containing approximately 1 wt% side-alkyl chains of $C_{16}$, and an anionic sodium dodecyl sulphate (SDS) surfactant was investigated. For a semi-dilute solution of 0.5 wt% hmHEC, the previously observed behaviour of a maximum in solution viscosity at intermediate SDS concentrations, followed by a drop at higher SDS concentrations, until above the cmc of surfactant when the solution resembles that of the unsubstituted polymer, was confirmed. Additionally, a two-phase region containing a hydrogel phase and a water-like supernatant was found at low SDS concentrations up to 0.2 wt%, a concentration which is akin to the critical association concentration, cac, of SDS in the presence of hmHEC. Above this concentration, SDS molecules bind strongly to form mixed micellar aggregates with the polymer alkyl side-chains, thus strengthening the network junctions, resulting in the observed increase in viscosity and elastic modulus of the solution. The shear behaviour of this polymer-surfactant complex during steady and step stress experiments was examined In great detail. Between SDS concentrations of 0.2 and 0.25 wt%, the shear viscosity of the hmHEC-polymer complex network undergoes shear-induced thickening, followed by a two-stage shear-induced fracture or break-up of the network. The thickening is thought to be due to structural rearrangement, causing the network of flexible polymers to expand, enabling some polymer hydrophobic groups to be converted from intra- to inter-chain associations. At higher applied stress, a partial local break-up of the network occurs, while at even higher stress, above the critical or network yield stress, a complete fracture of the network into small microgel-like units, Is believed to occur. This second network rupture is progressive with time of shear and no steady state in viscosity was observed even after 300 s. The structure which was reformed after the cessation of shear is found to be significantly different from the original state.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.147-147
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• 2016

In general, organic electrochromic (EC) materials have been known to be electrochemically unstable during the ionic exchange process. One effective method to realize stable EC materials is incorporating graphene derivatives in the polymer matrix, by using the strong interaction between graphene derivatives and polymer. However, previous studies are limited graphene derivatives. In this study, we developed a polymer-graphene derivative complex with the chemical assistance of a surfactant (octadecylamine, ODA). Surfactant-assisted graphene oxide (GO-ODA) was introduced as a protective layer on the electrochromic poly (3-hexyl thiophene) (P3HT) films by the Langmuir-Schaefer method. The deposition of GO-ODA protective layer with high coverage was confirmed by atomic force microscopy. The strong interactions between GO-ODA and P3HT were examined with UV-Vis spectrophotometry and X-ray photoelectron spectroscopy. Electrochemical and electrochromic investigations revealed that the GO-ODA layer greatly improved the long-term cyclability of the P3HT film. These findings imply that the GO-ODA complex has a significant role in creating stable EC cycling, due to its strong interaction with the P3HT film.

• Macromolecular Research
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• v.15 no.1
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• pp.51-58
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• 2007

The approach studied in the present work produced an exfoliated state of clay layers via confinement of the charged nano-sized polystyrene (PS) beads within the gallery of swollen pristine clay. It was demonstrated that adsorption of the polymer nanobeads dramatically promotes expansion of the clay gallery. A comparative study of incorporation was conducted by employing organo-modified clay along with two different colloid polymer systems: electrostatically stabilized PS nanobeads and cationic monomer-grafted PS nanobeads. The mechanism of adsorption of the monomer-grafted polymer beads onto clay via cationic exchange between the alkyl ammonium group of the polymer nanobeads and the interlayer sodium cation of the layered silicate was verified by using several techniques. As distinct from the polymer nanobeads formed using conventional miniemulsion polymerization method, competitive adsorption of stabilizing surfactant molecules was be prevented by grafting the surface functional groups into the polymer chain, thereby supporting the observed effective adsorption of the polymer beads. The presence of surface functional groups that support the establishment of strong polymer-clay interactions was suggested to improve the compatibility of the clay with the polymer matrix and eventually play a crucial role in the performance of the final nanocomposites.

• Carbon letters
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• v.27
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• pp.35-41
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• 2018

Surfactant-wrapped separation methods of metallic and semiconducting single-walled carbon nanotubes (SWCNTs) can result in large changes in intrinsic physical and chemical properties due to electronic interactions between a nanotube and a surfactant. Our approach to synthesize SWCNTs with an electronic feature relied on utilizing carbon nanorings, [n] cycloparaphenylenes ([n]CPPs), which are the fundamental unit of armchair type SWCNTs (a-SWCNTs) that possess a metallic feature without any surfactants. To obtain long tubular structures from [n]CPPs, the host-guest complexes formed with well-aligned [n]CPP hosts and various fullerene guests on a silicon substrate were pyrolyzed under an ethanol gas flow at a high temperature with focused-ultraviolet laser irradiation. The pyrolyzed [n]CPPs were observed to transform from nanorings to tubular structures with 1.5-1.7 nm diameters corresponding to the employed diameter of [n]CPPs. Our approach suggests that [n]CPPs are useful for structure-controlled synthesis of SWCNTs.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.3
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• pp.285-293
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• 2018

A structure of coacervate affects the adsorption of oil and polymer as a conditioning ingredient. This study aims to elucidate a structural characterization of the coacervate of which is a mixture of alkyl cellulose and guar gum. It is well known that the guar gum supports stiffness to the hair when it is adsorbed on the hair. However, addition of guar gum in the formulation composed of alkyl cellulose tremendously increased flexibility in hair. The stable complex system is induced by an electrostatic force between a head group of anionic surfactant and an quarternary ammonium at the alkyl cellulose, and the affinity of alkyl chain to the oil inside the micelle of surfactant by hydrophobic interactions. Taken together, amount of the coacervate increased oil-delivery upon hair in shampooing and these caused a low bending rigidity and calming on the hair swatch.