• Title, Summary, Keyword: 친유기

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Optimal Surfactant Structures for Cosurfactant-Free Microemulsion Systems (II) -Dialkylbenzene and Dialkylphenol Hydrophobes- (계면활성제의 구조가 Microemulsion 형성에 미치는 영향(제II보) -친유기 Dialkylbenzene과 Dialkylphenol-)

  • 김천희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.3
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    • pp.419-428
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    • 1994
  • Microemulsion을 형성하기 위해서는 일반적으로 주계면활성제와 함께 보조계면황성제가 첨가 된다. 그러나 보조계면활성제는 이론적으로 반드시 필요한 것은 아니며, 주계면활성제의 친유기 구조를 적절히 변화시킴으로써 보조계면황성제의 필요량을 감소시킬 수 있다. Microemulsion계 를 형성하기 위한 최적의 계면황성제구조를 찾기 위하여 twin tail형 계면활성제인 dialkylbenzene과 dialkylphenol친유기를 갖는 계면황성제를 연구하였다. p-dihexylbenzene sodium sulfonate는 보조계면활성제 없이 microemulsion을 형성하였지만, dialkylphenol sodium sulfates는 젤이나 액정등을 제거하기 위하여 보조계면활성제를 필요로 하였다.

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Mechanism of Action of Fatty Alcohol Ethoxylate on Foliar Penetration of Dimethomorph into Cucumber (Fatty Alcohol Ethoxylate에 의해 유도되는 Dimethomorph의 오이 엽면 침투 기작)

  • Yu, Ju-Hyun
    • The Korean Journal of Pesticide Science
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    • v.12 no.2
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    • pp.127-133
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    • 2008
  • The foliar uptake of dimethomorph into cucumber was assessed by spray application of aqueous dimethomorph solution containing fatty alcohol ethoxylate (FAE) or fatty acid alkyl ester as activator adjuvants. Afterward, the possible mechanism of action of FAE on foliar penetration of active ingredient was suggested by speculating on the effect of lipophile and hydrophile of FAEs. The amount of absorbed dimethomorph induced by polyoxyethylene mono-9-octadecenyl ether (6 moles ethylene oxide, $C_{18=9}E_6$) was linearly related to the concentrations of surfactant as well as dimethomorph in spray solution, suggesting that it is simply a diffusion phenomenon of the solute molecule through a cuticular membrane from leaf surface. Octadecanol attached to FAE was most effective lipophile on the leaf penetration of dimethomorph. And, the more ethylene oxide had the polyoxyethylene chain of FAE up to 20 moles, the higher the uptake rate was. Therefore, the role of lipophile of FAE on dimethomorph penetration to cucumber leaf, probably, is to modify the physico-chemical properties of cuticular membrane to be permeable to dimethomorph, and the polyoxyethylene chain having less than 20 moles ethylene oxide, which is moderately permeable to cuticular membrane by its molar volume, is to let the physically-modified cuticular membrane to be maintained for a longtime.

Synthesis and Characterization of Heat Resistant Organophilic Layered Silicate Modified with Oligo(amic acid)s Having Alkyl Side Chains and Their Nanocomposites (알킬기가 도입된 올리고 아믹산 구조를 가진 고내열 친유기 층상 실리케이트의 제조 및 이를 이용한 나노복합재의 특성평가)

  • Han Ji Yun;Won Jong Chan;Lee Jae Heung;Suh Kyung-Do;Kim Yong Seok
    • Polymer Korea
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    • v.29 no.5
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    • pp.451-456
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    • 2005
  • In the field of designing of nano-fillers of polyimide nanocomposites, the two strategic points are the heat-resistance and compatibility with polyimide, a matrix polymer. In this study, we designed oligo(amic acid) having alkyl side chains and terminal amine groups to satisfy previous requirements and studied the modification of surface of layered silicates. Oligo(amic acid)s were prepared by the reaction of diamine monomers and PMDA and their molecular weight was controlled in about 2000g/mol. After that, acidification and ion exchange reaction led to the high-temperature organophilic layered silicate (OLS). XRD pauerns of OLS showed the more increased gallery spacing by $4{\AA}$ than that of the pristine layered silicate and the initial decomposition temperatures of OLS were in above $280^{\circ}C$. The polyimide nanocomposite films based on heat resistant OLS showed that the OLSs were well dispersed through the matrix and their CTEs showed a decrease of $26\%$ compared with pristine polyimide films.

Optimal Surfactant Structures for Cosurfactant-Free Microemulsion Systems (III) -Nonylphenol and Tridecyl Alcohol Hydrophobes- (계면활성제의 구조가 Microemulsion 형성에 미치는 영향(제 III보) -친유기 Nonylphenol과 Tridecyl alcohol-)

  • 김천희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.4
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    • pp.473-479
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    • 1994
  • 보소계면활성제 없이 microemulsion을 형성하는 최적의 계면활성제 구조를 찾기 위한 일련의 연구 중 세번째로 propoxylated nonylphenol sulfates와 ethoxylated 혹은 propoxylated highly-branched tridecyl alcohol sulfates를 연구하였다. 온도, NaCl농도, 보조계면활성제 농도, ethylene oxide몰수(EON), propylene oxide몰수(PON) 등을 변인으로 하여 phase behavior 실험을 한 결과 tridecyl alcohol 친유기를 갖는 계면활성제가 보조계면활성제 없이 microemulsion을 형성하였다. $C_{13}O(EO)_mPO)_nSO_3Na$ 일반식으로부터 m과 n을 변경시킴으로써 계의 다양한 조건을 만족시키는 계면활성제를 디자인할 수 있었다.

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Synthesis and Chnracterization of Organophilic Montmorillonites Modified with Alkyl Siloxane Amino 01igomers (알킬실록산 아민 올리고머 구조를 함유한 친유성 몬모릴로나이트의 제조 및 특성평가)

  • 김효주;김용석;원종찬;이미혜;최길영
    • Polymer Korea
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    • v.27 no.2
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    • pp.135-141
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    • 2003
  • A series of organophilic montmorillonites (MMTs) modified with various alkyl siloxane amino oligomer groups have been synthesized and their properties were investigated. New organophilic MMTs containing siloxane amino oligomers with alkyl group instead of conventional alkyl amines were synthesized to improve thermal stability as well as gallery spacing. The organophilic MMTs were synthesized from MMT by utilizing the siloxane amino oligomers with various alkyl groups in the water/dioxane solution, which was performed without aq. HCl. Thermal decomposition temperature, gallery spacing, and hydrophobicity of synthesized organophilic MMTs were investigated. X-ray diffraction and TEM experiment results on new organophilic MMTs demonstrated that introduction of siloxane amine oligomers increased d-spacing between silicate layers. The decomposition temperatures of new organophilic MMTs measured by TGA was remarkably improved above 200℃ as compared with those of conventional alkyl substituted organophilic MMTs.

Evaluation of scouring properties at critical micelle concentration for the most suitable usage of scouring agent (정련제의 최적 사용량 설정을 위한 임계미셀농도에서의 정련성 평가)

  • 장혜영;김지연;이기풍;윤남식;이문철
    • Proceedings of the Korean Fiber Society Conference
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    • pp.243-244
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    • 2003
  • 계면활성제는 모터오일, 제약, 비누, 세제 등의 용도가 다양한 화학 제품 중 하나이다. 계면활성제는 비극성의 긴 탄화수소 체인으로 이루어진 꼬리(tail)부분과 보통은 이온으로 이루어진 극성을 띄는 머리(head)부분으로 구성되어있다. 보통 계면활성제를 나타낼 때는 fig. 1의 성냥개비와 같은 모형으로 표시하는 경우가 많다. 머리부분이 친수기를 나타내고, 꼬리부분이 친유기를 나타낸다. (1-2) 물과 같은 극성용매에서, 친수성과 친유성의 두 가지의 특징을 동시에 가지고 있는 계면활성제는 미셀(micelle)이라고 알려진 정리된 분자 화합이 일어난다.[3] (중략)

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Recent Trends in Research of Polyglycerin Fatty Acid Esters (폴리글리세린지방산에스터의 최근 연구동향(제1보))

  • Rang, Moon Jeong
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.4
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    • pp.1443-1459
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    • 2019
  • Polyglycerol fatty acid ester nonionic surfactants have been used for a long time in foods and have been suggested as an alternative to the safety problems of PEG based nonionic surfactants. The polyglycerol fatty acid ester surfactants are synthesized by combining a hydrophilic polyglycerin and a lipophilic fatty acid. The hydrophilic polyglycerin is polymerized using glycerin, glycidol, epichlorohydrin, etc. The main issues of the polyglycerol polymerization reaction are to increase the content of the polyglycerol in the form of linear rather than branched or cyclic forms and to narrow the distribution of the degree of polymerization. The method of binding a lipophilic fatty acid group to a hydrophilic polyglycerin includes chemical synthesis such as esterification reaction and enzyme synthesis using lipase enzyme. The main issues of polyglycerin fatty acid ester synthesis are to increase the yield and to control the degree of esterification while reducing side reactions.

Preparation of Organophilic MMT Modified with Various Aromatic Amines and Characterization of Polyimide Nanocomposite Films (다양한 구조의 방향족 아민으로 개질된 친유기성 MMT의 제조와 이를 이용한 폴리이미드 나노복합필름의 특성)

  • Han, Seung San;Choi, Kil-Yeong;Im, Seung Soon;Kim, Yong Seok
    • Applied Chemistry for Engineering
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    • v.17 no.2
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    • pp.177-182
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    • 2006
  • In this work, we have prepared organophilic MMT having thermal stability by ion exchange reaction of various aromatic ammonium salts with MMT containing sodium ion. The organic modifiers having alkyl side chains and amine functional group were successfully synthesized by effectively introducing the surfaces of MMT via ion exchange reaction to form organophilic MMTs with a view to improve the reactivity and thermal stability. The WAXD patterns of organophilic MMT showed the more increased gallery spacing by $3.3{\AA}$ than that of the pristine MMT and also the onset of initial decomposition of organophilic MMT was $275^{\circ}C$ as determined by a thermogravimetric analysis. The polyimide (PI) nanocomposite films based on poly(amic acid) and organophilic MMT were prepared by a solution blending followed by cyclodehydration reaction. We have investigated the dispersity of organophilic MMTs in PI matrix by using WAXD and the effect of the organophilic MMT content on the mechanical properties of PI nanocomposite films was studied.

Synthesis and Characterization of Organophilic Montmorillonites Modified with Various Alkyl Substituents (다양한 구조의 알킬기를 함유한 친유성 몬모릴로나이트의 제조 및 특성 연구)

  • 심종천;김용운;원종찬;최길영;이미혜
    • Polymer Korea
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    • v.27 no.2
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    • pp.129-134
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    • 2003
  • It has been known that the intercalation of long alkyl chains in montmorillonites (MMT) increased the hydrophobicity as well as gallery spacing of UT, which has influenced on the exfoliation behavior of various polymers. A series of organophilic MMTs were synthesized from the water/isopropyl alcohol solution of MMT with ammonium salts of various alkyl amines. The properties of obtained MMTs such as thermal decomposition temperature, gallery spacing as well as hydrophobic property were investigated. The X-ray diffraction experiments on organophilic montmorillonite demonstrated that the increase of length of alkyl substituent resulted in increase in the spacing between silicate layers, which was ranged from 13.1 to 29.4 $\AA$. On the other hand, introduction of (di-, tri-) alkyl substituents in ammonium salts decreased water absorption of organophiplic montmorillonite to 2.7%.

Molecular Area and Interfacial Tension Behavior of Span 20 and Tween series surfactants at water/air interface (Span 20과 Tween계 계면활성제의 물/공기 계면에서의 분자면적과 계면장력 거동)

  • 김천희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.7
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    • pp.1065-1072
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    • 2000
  • The molecular areas and the interfacial tension behavior of ten nonionic surfactants, i.e., Span 20 and Tween 20, 40, 60. 80, 21, 61, 81, 65, & 85 are tested to assay their effects on the wetting and liquid retention properties of hydrophilic and hydrophobic fibrous materials. The molecular areas at water/air interface are derived from Gibbs’adsorption equations. The following conclusions are drawn from the results: 1) Span 20 is efficient in lowering the interfacial tension and effective in adsorption at the water/air interface, resulting in the low interfacial tension at critical micelle concentration (${\gamma}$$_{CMC}$) and a small molecular area($\omega$), 2) when the hydrophiles of the surfactants are constant, $\omega$’s increase as hydrophobe carbon numbers of the surfactants increase, 3) when the hydrophobes are constant, ${\gamma}$$_{CMC}$’s and $\omega$’s increase as the hydrophile ethylene oxide units increase, indicating effectiveness and efficiency is parallel in this case, 4) the ethylene oxide unit length as a hydrophile has greater influence on u than the hydrophobe chain length.han the hydrophobe chain length.gth.

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