• Title/Summary/Keyword: emulsifier charge

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Effect of Glutamic Acid and Monosodium Glutamate on Oxidative Stability of Riboflavin Photosensitized Oil-in-Water Emulsion

  • Ji-Yun Bae;Mi-Ja Kim
    • The Korean Journal of Food And Nutrition
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    • v.37 no.1
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    • pp.48-56
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    • 2024
  • Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

A study on the Coating Structure and Printability of Coated Paper (I) - Effect of Ionic Monomer on Paper-coating Latex Properties - (도공층 구조 및 도공지의 인쇄적성에 관한 연구 (I) - 이온성 단량체가 도공용 라텍스의 물성에 미치는 영향 -)

  • Lee, Yong-Kyu
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.3
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    • pp.75-82
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    • 1997
  • To improve the quality of coated paper, the continuous research to the coating components and development of alternative latices is required. Recently, amphoteric latex is getting a great concern due to their changable properties of surface charge through controlling pH and some methods have been tried to prepare amphoteric latices. This study was carried out to synthesize amphoteric latex using seeding polymerization method with low concentration emulsifier. Styrene was used as a main monomer in addition to acrylonitrile for a hydrophilic comonomer. acrylic acid for a anionic comonomer and N,N-dimethylaminoethyl methacrylate for a cationic comonomer. Particle size and viscosity of latex were greatly affected by addition of acrylic acid and ammonium persulfate as an initiator. Negative charge of latex in alkali condition was changed to zero to positive charge in around pH 4.

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Influence of pH, Emulsifier Concentration, and Homogenization Condition on the Production of Stable Oil-in-Water Emulsion Droplets Coated with Fish Gelatin

  • Surh, Jeong-Hee
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.999-1005
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    • 2007
  • An oil-in-water (O/W) emulsion [20 wt% com oil, 0.5-6.0 wt% fish gelatin (FG), pH 3.0] was produced by high pressure homogenization, and the influence of pH, protein concentration, and homogenization condition on the formation of FG-stabilized emulsions was assessed by measuring particle size distribution, electrical charge, creaming stability, microstructure, and free FG concentration in the emulsions. Optical microscopy indicated that there were some large droplets ($d>10\;{\mu}m$) in all FG-emulsions, nevertheless, the amount of large droplets tended to decrease with increasing FG concentration. More than 90% of FG was present free in the continuous phase of the emulsions. To facilitate droplet disruption and prevent droplet coalescence within the homogenizer, homogenization time was adjusted in O/W emulsions stabilized by 2.0 or 4.0 wt% FG. However, the increase in the number of pass rather promoted droplet coalescence. This study has shown that the FG may have some limited use as a protein emulsifier in O/W emulsions.

Preparation of Colored Electrophoretic Nanoparticles by Emusifier-Free Emulsion Polymerization and Reactive Dyeing (무유화 에멀젼 공중합법과 반응염법을 이용한 전기영동 고분자 컬러나노입자의 제조)

  • Chon, Jin-A;Ha, Jae-Hee;Lim, Min-Ho;Kwon, Yong-Ku
    • Polymer(Korea)
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    • v.34 no.6
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    • pp.491-494
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    • 2010
  • Colored, electrophoretic polymer nanoparticles of poly (styrene-co-divinylbenzene-co-vinyl acetate)[poly(St-co-DVB-co-VAc)] were prepared by emulsifier-free emulsion co-polymerization and reactive dyeing. The emulsifier-free emulsion polymerization of styrene, divinyl benzene and vinyl acetate was carried out at $70^{\circ}C$ for 20 hrs to obtain monodisperse polymer nanoparticles of poly(St-co-DVB-co-VAc) with an average diameter of 180~200 nm. These nanoparticles were transformed into poly(styrene-co-divinylbenzene-co-vinyl alcohol) [poly(St-co-DVB-co-VA)] nanoparticles through the saponification reaction. The poly(St-co-DVB-co-VA) nanoparticles were treated with reactive dyes to obtain the colored, monodisperse electrophoretic nanoparticles, and their morphology and surface charge were characterized by scanning electron microscopy, differential scanning calorimetry, UV/Vis absorbance and zeta-potentiometry.

Preparation of Polystyrene Particles Containing Poly(ethylene glycol) Groups and Their Surface Charge Characterization in Dielectric Medium (폴리(에틸렌 글리콜)기를 갖는 폴리스티렌 입자의 제조와 유전 매질내에서의 표면 전하 특성)

  • 김성훈;김배중;권대익;박기홍
    • Polymer(Korea)
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    • v.28 no.6
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    • pp.524-530
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    • 2004
  • Polystyrene particles (PS) with poly(ethylene glycol) units on surface were formed by an emulsifier-free emulsion polymerization using styrene, poly(ethylene glycol) methacrylate (PEG-MMA) or poly(ethylene glycol) dimethacrylate (PEG-diMMA) at pH 7, and followed by freeze-drying to give the corresponding powders. The structures of PS particles were confirmed by FT-IR spectroscopy, and the particle size and distribution the PS particle were observed by scanning electron microscopy and particle analyzer. Monodisperse polymer particles were obtained at a concentration of PEG-MMA 2∼5 mol% or PEG-diMMA 1 mol% relative to styrene. The highest zeta potential of polymer surface was measured to be 183 mV at a polymer of PEG-MMA 5 mol%, which was measured in dielectric medium by means of ELS-8000 dynamic light scattering.

Interfacial Electric Property of PVA/PVAc Particles (PVA/PVAc 입자의 계면 전기적 성질)

  • Lee, Ha-Na;Lee, Jae-Woong;Kim, Ji-Young;Lee, Won-Chul;Kim, Sam-Soo
    • Textile Coloration and Finishing
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    • v.20 no.6
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    • pp.8-17
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    • 2008
  • Poly (vinyl acetate) (PVAc) was used as a precursor of PVA/PVAc (skin/core) bicomponent. In order to investigate the possibility of PVA particles for electrical applications, PVA/PVAc particles were produced with an emulsifier, SDS (Sodium Dodecyl Sulfate) and an initiator, V-50 (2,2'-azobis(2-amidinopropane)digydrochloride). In this study, we investigated the electrical property of PVA/PVAc (skin/core) particles. The hydroxyl group of the PVA/PVAc (skin./core) was confirmed by the analysis of PVAc and PVA/PVAc (skin/core) using Fourier Transform Infrared Spectroscopy (FT-IR). The zeta-potential of the PVA/PVAc (skin/core) and PVAc has similarity; however, charge control agent (CCA) treated PVA/PVAc (skin/core) particles has lower zeta-potential than untreated PVA/PVAc particles. The zeta-potential (negative values) of the PVA/PVAc (skin/core) were enhanced in proportion to the increased concentration of CCA.

Preparation and Surface Charge Characterization of Polystyrene Particles and Powders with Carboxyl and/or Poly(ethylene glycol) Groups

  • Kim, Bae-Joong;Kim, Seong-Hun;Park, Ki-Hong
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.94-94
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    • 2003
  • Cross-linked polystyrene (PS) particles with carboxyl and/or poly(ethylene glycol) units on surface were formed by an emulsifier-free emulsion polymerization using styrene, methacrylic acid (MA), and poly(ethylene glycol) dimethacrylate (PEG-diMMA) at pH 7, and followed by freeze-drying to give the corresponding powders. Monodisperse polymer particles could be obtained at a concentration of PEG-diMMA 1 mol% relative to styrene. Zeta potential of polymer surface was measured to be 91 mV at a polymer of PEG-diMMA 1 mol% and was dropped as the content of MA increased.

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Formulation and Antimicrobial Activity on Escherichia coli of Nanoemulsion Coated with Whey Protein Isolate

  • Bejrapha, Piyawan;Choi, Mi-Jung;Surassmo, Suvimol;Chun, Ji-Yeon;Min, Sang-Gi
    • Food Science of Animal Resources
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    • v.31 no.4
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    • pp.543-550
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    • 2011
  • Various concentrations of whey protein isolate (WPI), such as 0.1, 0.5, 1.0, 2.5, and 5.0%(w/v), containing 1.0%(w/v) eugenol were prepared by high speed homogenization to formulate nanoemulsions (NEs) and to investigate their antimicrobial activity. The results showed that particle size decreased according to increases in WPI concentration. Similarly, the ${\zeta}$-potential value was reduced to a negative charge when using WPI concentrations >0.1%(w/v). In contrast, no significant differences in particle size were observed during 1 mon of storage, except for the 0.1%(w/v) WPI NE. The ${\zeta}$-potential value depended on the increase in WPI concentration and storage duration, except for NE1 and NE5, suggesting that a low or high concentration of emulsifier was not effective for maintaining the droplet form of the eugenol NE. The results of an antibacterial effect investigation indicated that the growth of Escherichia coli was inhibited based on an increase in eugenol concentration in all NE formulations. Moreover, a membrane permeability study showed that total leakage content increased according to incubation time.

Preparation and Characteristics of Polypyrrole/sulfonated Poly(2,6-dimethyl-1,4-phenylene oxide) Composite Electrode (폴리피롤/설폰화 폴리(2,6-디메틸-1,4-페닐렌 옥사이드) 복합전극의 제조 및 특성)

  • Huh, Yang-Il;Jung, Hong-Ryun;Lee, Wan-Jin
    • Polymer(Korea)
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    • v.31 no.1
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    • pp.74-79
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    • 2007
  • Polypyrrole (PPy) was made by an emulsion polymerization using iron (III) chloride ($FeCl_3$) as an initiator and dodecyl benzene sulfuric acid (DBSA) as an emulsifier and dopant. Poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) was sulfonated by chlorosulfonic acid (CSA). The cathode was composed of $PPy^+DBS^-$ complex, conductor powder, and PPO or sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (SPPO) as a binder or dopant. The charge-discharge performance of $PPy^+DBS^-/SPPO$ cathode was increased as the extent of about 50%, than $PPy^+DBS^-/PPO$. This is because SPPO played a role as a binder as well as a dopant. In addition, sulfonation brings out the increase of miscibility between PPy and SPPO, and the increase of contact area between cathode and electrolyte.

Relative Bioavailability of Coenzyme Q10 in Emulsion and Liposome Formulations

  • Choi, Chee-Ho;Kim, Si-Hun;Shanmugam, Srinivasan;Baskaran, Rengarajan;Park, Jeong-Sook;Yong, Chul-Soon;Choi, Han-Gon;Yoo, Bong-Kyu;Han, Kun
    • Biomolecules & Therapeutics
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    • v.18 no.1
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    • pp.99-105
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    • 2010
  • The purpose of this study was to evaluate relative bioavailability of the coenzyme Q10 (CoQ10) in emulsion and three liposome formulations after a single oral administration (60 mg/kg) into rats. Emulsion formulation of CoQ10 was prepared by conventional method using Phospholipon 85G as an emulsifier, and three liposome formulations (neutral, anionic, and cationic) of CoQ10 were prepared by traditional lipid film hydration technique using Phospholipon 85G, cholesterol, and charge carrier lipids (1,2-dioleoyl-3-trimethylammonium-propane chloride salt for cationic liposome and 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt for anionic liposome). Mean particle size of all CoQ10-loaded liposome was less than a micron, and size distribution of the liposome population was homogeneous. Bioavailability of CoQ10 in emulsion was 1.5 to 2.6-fold greater than liposome formulations in terms of $AUC_{0-24\;h}$. $T_{max}$ was 3 h when administered as emulsion while it was greater than 6 h in liposome formulations. Notably, it was approximately 8 h in cationic liposome. $C_{max}$ was highest in emulsion and was significantly decreased when administered as liposome. Charged liposome showed even lower $C_{max}$ than neutral liposome, especially in cationic liposome. In conclusion, therefore, it is suggested that clinicians and patients consider bioavailability issue a primary concern when choosing a CoQ10 product, especially when very high plasma level is required such as in the treatment of heart failure and Parkinson's disease.