• Title/Summary/Keyword: $\zeta$-potential

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A Study on the Stability of DOPC Liposome (염의 농도에 따른 DOPC 리포좀의 안정성에 관한 연구)

  • Won, Doo-Hyun;Kim, Sun-Young;Lim, Gyu-Nam;Park, Soo-Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.37 no.1
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    • pp.55-60
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    • 2011
  • In this study, DOPC liposomes were prepared with distilled water, phosphate buffer and phosphate buffered saline to evaluate the effects of salt on the stability of DOPC liposome. The changes in physical properties (likeparticle size and zeta potential) of liposome were measured after adding the salt. Liposomes were diluted 40 times and 80 times with hydration solvent to confirm the effect of dilution. Consequently, the stability of liposome was maintained up to 40 times dilution with hydration solvent. The liposome that prepared with distilled water was diluted with distilled water, phosphate buffer and phosphate buffered saline, and the liposome that prepared with phosphate buffer was diluted with phosphate buffer and phosphate buffered saline to evaluate the salt-induced changes in particle size and zeta potentia. As results, the particle size increased slightly and zeta potential became closer to 0 when the salt concentration was increased. In conclusion, particle size and zeta potential of liposome could be reasonable factors to evaluate the stability of liposome. In addition, we suggest that salt concentration of hydration solvent has a significant effect on the stability of liposome.

LOG-SINE AND LOG-COSINE INTEGRALS

  • Choi, Junesang
    • Honam Mathematical Journal
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    • v.35 no.2
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    • pp.137-146
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    • 2013
  • Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the log-sine and log-cosine integrals have been evaluated, in the existing literature on the subject, in many different ways. The main object of this paper is to present explicit evaluations of some families of log-sine and log-cosine integrals by making use of the familiar Beta function.

Preliminary Study on Properties of Layer-by-Layer Assembled GCC with Polyelectrolytes (고분자전해질의 LbL 흡착 처리에 의해 개질된 중질탄산칼슘의 특성 기초 연구)

  • Lee, Je-Gon;Ryu, Jae-Ho;Sim, Kyu-Jeong;Ahn, Jung-Eon;Lee, Hak-Lae;Youn, Hye-Jung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.3
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    • pp.35-42
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    • 2011
  • In this study, ground calcium carbonate (GCC) was modified by Layer-by-Layer (LbL) multilayering with polyelectrolytes. Cationic polyacrylamide (C-PAM) and poly sodium 4-styrene sulfonate (PSS) were used as cationic and anionic polyelectrolytes to modify GCC. The characteristics of the modified GCC were examined in terms of zeta potential and particle size with the addition level of polyelectrolyte and layer number. The GCC could form an assembly of cationic and anionic polyelectrolytes through consecutive adsorption process. The zeta potential of the modified GCC moved toward the cationicity and reached the plateau with the increase of the addition level of C-PAM. With layering of anionic PSS, the GCC had the negative charge. The particle size was dependent on the zeta potential. It was also observed by optical microscope. As the PSS was in the presence of the outermost layer, the GCC showed the better dispersability. It indicated that the surface charge and particle size can be controlled by adjusting the addition level of polyelectrolyte and the layer number.

Electrokinetic flow and electroviscous effect in a charged slit-like microfluidic channel with nonlinear Poisson-Boltzmann field

  • Chun, Myung-Suk;Kwak, Hyun-Wook
    • Korea-Australia Rheology Journal
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    • v.15 no.2
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    • pp.83-90
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    • 2003
  • In cases of the microfluidic channel, the electrokinetic influence on the transport behavior can be found. The externally applied body force originated from the electrostatic interaction between the nonlinear Poisson-Boltzmann field and the flow-induced electrical field is applied in the equation of motion. The electrostatic potential profile is computed a priori by applying the finite difference scheme, and an analytical solution to the Navier-Stokes equation of motion for slit-like microchannel is obtained via the Green's function. An explicit analytical expression for the induced electrokinetic potential is derived as functions of relevant physicochemical parameters. The effects of the electric double layer, the zeta potential of the solid surface, and the charge condition of the channel wall on the velocity profile as well as the electroviscous behavior are examined. With increases in either electric double layer or zeta potential, the average fluid velocity in the channel of same charge is entirely reduced, whereas the electroviscous effect becomes stronger. We observed an opposite behavior in the channel of opposite charge, where the attractive electrostatic interactions are presented.

Assessment of Discoidal Polymeric Nanoconstructs as a Drug Carrier (약물 운반체로서의 폴리머 디스크 나노 입자에 대한 평가)

  • BAE, J.Y.;OH, E.S.;AHN, H.J.;KEY, Jaehong
    • Journal of Biomedical Engineering Research
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    • v.38 no.1
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    • pp.43-48
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    • 2017
  • Chemotherapy, radiation therapy, and surgery are major methods to treat cancer. However, current cancer treatments report severe side effects and high recurrences. Recent studies about engineering nanoparticles as a drug carrier suggest possibilities in terms of specific targeting and spatiotemporal release of drugs. While many nanoparticles demonstrate lower toxicity and better targeting results than free drugs, they still need to improve their performance dramatically in terms of targeting accuracy, immune responses, and non-specific accumulation at organs. One possible way to overcome the challenges is to make precisely controlled nanoparticles with respect to size, shape, surface properties, and mechanical stiffness. Here, we demonstrate $500{\times}200nm$ discoidal polymeric nanoconstructs (DPNs) as a drug delivery carrier. DPNs were prepared by using a top-down fabrication method that we previously reported to control shape as well as size. Moreover, DPNs have multiple payloads, poly lactic-co-glycolic acid (PLGA), polyethylene glycol (PEG), lipid-Rhodamine B dye (RhB) and Salinomycin. In this study, we demonstrated a potential of DPNs as a drug carrier to treat cancer.

Stability of Henna Natural Hair Dye Cream Formulation According to Cetyl Alcohol Contents (Cetyl alcohol 함량에 따른 크림 제형 Henna 천연 염모제의 안정성)

  • Kang, Eyoung;Lee, Seunghee;Kim, Woonjung;Jung, Jongjin
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.4
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    • pp.1176-1182
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    • 2021
  • In this study, the emulsion stability of henna, a natural hair dye, according to the content of cetyl alcohol, one of the emulsification stabilizers, was analyzed, and the content of cetyl alcohol showing the most stable emulsification was confirmed. To analyze the emulsion stability, differences in particle size, particle shape, viscosity, and color after dyeing were compared according to the content of cetyl alcohol. As a result of dynamic light scattering (DLS) zeta analysis, cetyl alcohol 3% showed the highest zeta potential value of 115.9 mV, and the particle size distribution was henna in which a cream-type hair dye containing 3% cetyl alcohol was dispersed in distilled water. The width of the particle size distribution was narrow compared to. As a result of viscometer analysis, the viscosity increased as the content of cetyl alcohol increased. As a result of measuring the henna pH of the cream formulation, it was measured in a pH range suitable for the scalp. As a result, emulsion stability increases as the content of cetyl alcohol increases in henna cream formulations for hair dye.

A Study of the Effects of Na Ion on Codeposition of Particles in the Formation of Electroless Ni Composite Coatings (무전해 Ni 복합도금에서 분말의 공석에 미치는 Na 이온의 영향)

  • 이원해;이승평
    • Journal of the Korean institute of surface engineering
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    • v.22 no.2
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    • pp.101-108
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    • 1989
  • Effects of Na+ ion on zeta potential of SiC and Al2O3 particles suspended in nikel sufate and nickel chloride solutions were investigated. various complexing agents for Ni2+ ion were added to electroless Ni composite bath and the effects of the complexing agents on zeta potential and codeposition of the particles from the baths were studied. It was confirmed that Na+ ion was absorbed on the particles bringing about the positive surface charge and thus they promoted the entrapment of the particles into the nickel deposit. On the basis of these results it was possible to deposit SiCc particle in nickel chloride electrolyte containing complex agent such as trisodium citrate+sodium succinate.

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Removal of Se(IV) by the Fe(III)-impregnated Sea sand - Zeta potential approach to depict the binding between Fe(III) and Sea sand (표면 처리한 Sea sand를 이용한 Se(IV) 제거 - Zeta potential을 통한 Fe(III)간의 반은 메카니즘 연구)

  • 박상원;강혜정
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.205-209
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    • 1999
  • Iron hydroxides are good adsorbents for uncomplexed metals, some metal-ligand complexes and many metal oxyanions. However, their adsorption properties of these precipitations are not fully exploited in wastewater treatment operations because of difficulties associated with their separation from the aqueous phase. This study describes experiments in which iron hydroxides were coated onto the surface of ordinary adsorbents(Sea sand) that are very resistant to acids, The coated adsorbents were used in adsorption of oxyanionic metals. The process was successful in removing some anions such as $SeO_3(-II)$ over a wide range of metal concentrations and sorption of oxyanionic metals increased with decreasing pH. Formation of two surface complexes for oxyanionic metals adsorption on iron hydroxides comprise (1) complexation of the free anion by a positively charged surface site, and (2) protonation of the adsorbed anion (or alternatively adsorption of a protonated form from solution) The coated adsorbents are inexpensive to prepare and could serve as the basis of a useful oxyanionic metal removal.

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