• Title, Summary, Keyword: HLB value

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A Study on the Preparation of Tungsten Oxide powders Using Emulsion Evaporation Methods (에멀젼 증발법에 의한 산화텅스텐 분말의 제조에 관한 연구)

  • 신창훈;안종관;이응조
    • Journal of the Korean Ceramic Society
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    • v.35 no.6
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    • pp.543-550
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    • 1998
  • A process for the preparation of spherical tungsten oxide powders by the emulsion evaporation method was developed. The characteristics of the powders thus prepared were examined by means of TGA X-ray diffraction SEM and image analysis. The emulsion was prepared by fast mixing of tungsten containing aque-ous phase and the organic phase which contained kerosene surfactant and paraffin oil. The precursor was made by evaporating the emulsion in the kerosene bath at $160^{\circ}C$ and then calcined at $650^{\circ}C$ in order to pro-duce tungsten oxide powders. The average particle size of the tungsten oxide powders was $0.5\;\mu\textrm{m}$ and their shapes were spherical. Water-in-oil type emulsion wasmore advantageous to make less agglmerated. $W_{3}$ powders than the oil-in-water type emulsion for the emulsion evaporation experiments. As the HLB value of the surfactant increased and the concentration of tungsten ions in the aqueous phase decreased the mean particle size of tungsten oxide powders decreased whereas agglomeration increased. The optimum con-centration of Span 80 was 8 percent by volume and the optimum stirring speed in the emulsion formation was 5000 rpm in order to obtain find less agglomerated $W_{3}$ powders.

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A Study on the Preparation of PBAST/PVA Double Layered Hollow Microspheres (PBAST/PVA 이중층 중공미세구의 제조에 관한 연구)

  • Song, Myung-Sook;Woo, Je-Wan
    • Clean Technology
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    • v.14 no.4
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    • pp.256-264
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    • 2008
  • In this study, using PBAST (poly(butylene adipate-co-succinate-co-terephthalate)) which was eco-friendly biodegradable aliphatic polyester, PBAST/PVA (poly(vinyl alcohol)) double-layered hollow microspheres were prepared with the water/oil/water multiple emulsion ($W_1/O/W_2$) method. The double-layered hollow microspheres were manufactured with the yield of 30.92% when the concentration of polymer PBAST in organic phase was 5 wt%, the concentration of PVA in inner aqueous phase was 5 wt%, the volume ratio of $W_1/O$ emulsion to outer aqueous phase was 1:4.5, and when co-surfactants that had large gap in HLB (hydrophile-lipophile balance) value were used. The bulk density of prepared hollow microsphere was 0.180 g/ml and particle size was $1.5{\sim}3\;{\mu}m$.

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The Effect of Nonionic Surfactants on the Solubility and Biodegradation of PAHs in Soil Slurry (PAHs의 용해도와 생분해에 미치는 비이온계 계면활성제의 영향)

  • 박종섭;김인수
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.174-177
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    • 1998
  • The effects of surfactants affecting polycyclic Aromatic Hydrocarbon(PAHs) solubility and biodegradation in soil slurry were investigated. The critical micelle concentration(CMC) values of surfactants used in this study were 12.7mg/L(Brij 30), 13.4mg/L(Tween 80), 13.6mg/t(Triton X-100). The solubility of PAH increased as the Hydrophile-Lipophile Balance(HLB) value of surfactant decrease. At surfactant biodegradation and toxicity experiement using respirometer, Brij 30 did not show any toxic effect and substrate inhibition upon the level of 1.5g/L. Also, biodegradation of Brij 30 gave no reduction on the phenanthrene biodegradation rate. When the desorption rate of phenanthrene between sand and clay is compared, lower percentage of phenanthrene was desorbed at clay because of the larger surface aera and higher organic content of clay. At the biodegradation experiments of phenanthrene in soil slurry phase, more than 90% of initial phenanthrene adsorbed onto both sand and clay were biodegraded by phenanthrene- acclimated cultures.

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Phaffia rhodozyma로부터 천연성 고기능 항산화제 Astaxanthin의 미셀형성을 통한 가용화 및 추출

  • Kim, Yeong-Beom;Lee, Eun-Gyu;Lee, Sang-Yun;Im, Gyo-Bin
    • 한국생물공학회:학술대회논문집
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    • pp.198-201
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    • 2000
  • The capacity of micelle formation between astaxanthin and various surfactants was compared. Tween 20 was identified the most suitable surfactant in terms of astaxanthin extraction capacity. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effect of micelle formation condition, such as molar ratio of astaxanthin and Tween 20, pH and ionic strength was also investigated. pH and ionic strength showed no significant effects. Antioxidant activity of astaxanthin was twice of ${\alpha}-tocopherol$ and 4 times of ${\beta} -carotene$. Crude astaxanthin extract from the yeast cell seemed to be less degraded than pure astaxanthin by air and light exposure, probably because of the presence of other carotenoids and lipids. Under the optimal conditions, the molar ratio of micelle formed was found to be 1 : 12 for astaxanthin : Tween 20.

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Preparation and Properties of Fatty Alkylate Type Durable Softner for Nylon Fiber (알킬지방산 에스테르계 나일론 섬유용 내구성 유연제의 제조와 물성)

  • Kim, Seung-Jin;Park, Hong-Soo;Kang, Doo-Whan
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.1
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    • pp.87-92
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    • 1995
  • To prepare a O/W type durable softner(OESA), octadecamidoethylaminoethyl dodecate and tetra (2-dodecamidoethyl) urea synthesized as the main components of softner, were blended with polyoxyethylene(20) oleyl ether, sorbitan sesquioleate, and polyoxyethylene(7) stearyl ether in various compositions. Emulsion stability of OESA was good, and mixed HLB value was 9.7, OESA was found was to be good durable softner for nylon through the examination of softness, lubriation, antistatic property, bending resistance, and color fastness.

Physicochemical Characteristics of Surfactant Added Sweet Potato Starch (Surfactant 를 처리한 고구마 전분의 물리 화학적 특성)

  • Lee, Shin-Kyung;Shin, Mal-Shick
    • Korean journal of food and cookery science
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    • v.8 no.3
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    • pp.255-263
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    • 1992
  • Pasting characteristics and amylose-surfactant complex forming ability of sweet potato starch were investigated after defatting and the addition of surfactants, such as SSL (sodium steamyl-2-lactylate) Dimodan (mono/di glyceride) and SE (sucrose ester) with different concentrations. All starch granules were smooth and round, there were no damages to starch granules after defatting and surfactant addition. amylose content of surfactant added stach decreased and me order of decrease was SSL, SE and Dimodan. The cornplex forming ability of SE added starch increased according to increasing HLB value. As surfactants concentration increased, amylose complex formig ability increased. In case of gelatinization patterns by amylograph, the initial pasting temperature of surfactant added starches was higher than mat of untreated or defatted starches, but viscosity at each temperature were all decreased. Soluble carbohydrate and leached amylose of starches increased at increasing temperature, those of surfactant added starches decreased at each temperature in the order of SSL, SE and Dimodan.

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Preparation and Characteristics of Ahcovel Type Nonionic Durable Softner (Ahcovel계 비이온성 내구유연제의 제조와 유연특성 연구)

  • Shin, Jae-Hyun;Kim, Sung-Gea;Park, Hong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.15 no.1
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    • pp.17-23
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    • 1998
  • To prepare a O/W type nonionic durable softner(ANSA), synthesized 1, 3-dihexadanoyl-2, 7-dioxy-6, 8-di(2-hexadecanoyloxyethyl)-1, 3, 6, 8-tetraazacyclodecane as the main component of softner, was blended with beef tallow, anhydrous lanolin, polyoxyethylene(20) oleyl ether, sorbitan sesquioleate, and polyoxyethylene(7) stearyl ether in various compositions. Emulsion stability of ANSA was good, and the mixed HLB value was 9.8. After the treatment of ANSA to all cotton fabrics, the physical properties such as tear strength, crease recovery, and flexing abrasion resistance were measured, respectively. As a result of the measurement, ANSA was proved to be durable softner with good softness.

Back-Extraction Processes of C.C.Lipase with Mediated AOT Reverse Micellar System

  • Lee, Sung-Sik;Kim, Bong-Gyu;Sung, Nak-Chang;Lee, Jong-Pal
    • Bulletin of the Korean Chemical Society
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    • v.25 no.6
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    • pp.873-877
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    • 2004
  • The relationship between the behaviors of c.c.lipase back-extraction and their percolation phenomena by using AOT reverse micellar systems (RVMS) has been studied by the addition of a small amount of additives to organic phase such as thiols and nonionic-surfactants focusing on micelle-micelle interactions. The values of ${\beta}_t$ defined by the variation of percolation processes and back-extraction behaviors of c.c.lipase have a good linear correlation. The hydrophobicity of additive molecules suppressing the cluster formation of reverse micelles (high values of ${\beta}_t$) improved the back-extraction behavior of c.c.lipase. The back-extraction fraction and its rate of c.c.clipase are increased with decreasing of the value of hydrophilic lipophilic balance (HLB) and increasing of the hydrophobicity per additive molecules added to reverse micellar systems (RVSM) in the same additives concentration.

A Study on Synthesis of Organic Plant Surfactant and Its Solubilizing Action on Bergamot Oil (유기농 식물성 계면활성제의 합성과 베르가못오일에 대한 가용화력에 관한 연구)

  • Kim, In-Young;Noh, Ji-Min
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.4
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    • pp.1208-1218
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    • 2019
  • The study is on the cosmetic solubilizing power of organic plant surfactants. The blended high purity polyglyceryl-10 oleate and polyglyceryl-10 stearate mixtures were synthesized using organically certified raw materials to develop surfactants having excellent solubilizing power. The mixture is called "Solubil ORG-1300". The appearance of this material is a pale yellowish paste, with a specific odor. The specific gravity was 1.12 and it was high purity that acid value was 0.072±0.1. The HLB value of this natural surfactant was averaged = 15.1 and calculated through the Griffin equation. Mechanically it is explained how organic surfactant are available with fragrance and oils. The solubilizing test was determined by eye evaluation method through the dissolving performance test for the two oils and measured the transmittance at 890 nm using a UV spectrophotometer to measure the transparency. The results showed that the concentration of surfactant needed to make Bergamot oil available requires approximately more 2 times. It was also found that the concentration of surfactant needed to make the tocoperyl acetate available was about 8 times higher. Experiments on the solubility resulting from pH changes showed stabilized usable solubilizing power even in acidic areas of pH=3.5, neutral areas of pH=7.2, and alkaline areas of pH=1.5. Experiments on the solubility according to pH variation showed good solubility stabilized in acidic areas of pH=3.5, neutral areas of pH=7.2, and alkaline areas of pH=11.5. As an application of cosmetics, the company successfully developed a prescription for moisturizing activity based on these results, it is expected that a wide range of applications will be available for skin care, baby lotion, sensitivity or atopic skin cosmetics.

Genetic Variability Based on Tandem Repeat Numbers in a Genomic Locus of 'Candidatus Liberibacter asiaticus' Prevalent in North East India

  • Singh, Yanglem Herojit;Sharma, Susheel Kumar;Sinha, Bireswar;Baranwal, Virendra Kumar;Singh, N. Bidyananda;Chanu, Ngathem Taibangnganbi;Roy, Subhra S.;Ansari, Meraj A.;Ningombam, Arati;Devi, Ph. Sobita;Das, Ashis Kumar;Singh, Salvinder;Singh, K. Mamocha;Prakash, Narendra
    • The Plant Pathology Journal
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    • v.35 no.6
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    • pp.644-653
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    • 2019
  • The genetic variability of 'Candidatus Liberibacter asiaticus' (CLas) population associated with huanglongbing (HLB) disease of citrus in North Eastern (NE) region of India, a geographically locked region, and home for the diversity of many citrus species was analyzed on the basis of tandem repeat numbers (TRN) in variable CLIBASIA_01645 genomic loci. Fifty-five CLas strains sampled from different groves of NE Hill (NEH) region of India were in single amplicon group, but there was remarkable genetic variability in TRNs. The TRN in HLB-associated CLas strains varied from 0-21 and two novel repeat motifs were also identified. Among the NE population of CLas, TRN5 and TRN9 were most frequent (total frequency of 36.36%) followed by TRN4 (14.55%) and TRN6, TNR7 with a frequency of 12.73% each. Class II type CLas genotypes (5 < TRN ≤ 10) had highest prevalence (frequency of 60.00%) in the samples characterized in present study. Class I (TRN ≤ 5) genotypes were second highest prevalent (29.09%) in the NEH region. Further analysis of genetic diversity parameters using Nei's measure (H value) indicated wide genetic diversity in the CLas strains of NE India (H value of 0.58-0.86). Manipur CLas strains had highest genetic variability (0.86) as compared to Eastern, Southern and Central India. The R10 values (TRN ≤ 10/TRN > 10) of NE CLas population was 10.43 (73/7), higher from other regions of India. Present study conclusively reported the occurrence of high genetic variability in TRN of CLas population in North East Indian citrus groves which have evolved to adapt to the specific ecological niche.