• Title, Summary, Keyword: physicochemical properties

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Synthesis and characterization of physicochemical properties of hydrophilic imidazolium-based ionic liquids

  • Yousefi, Maryam;Abdouss, Majid;Beigi, Ali Akbar Miran;Naseri, Ali
    • The Korean Journal of Chemical Engineering
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    • v.34 no.9
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    • pp.2527-2535
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    • 2017
  • A series of ionic liquids based on Octyl and Decyl methylimidazolium with different anions such as chloride, glycinate, dihydrogen phosphate and trihydrogen diphosphate, were synthesized and characterized by $^1HNMR$ and elemental analysis. IL containing trihydrogen diphosphate anion, was synthesized for the first time. Physicochemical properties, including density, viscosity, surface tension, refractive index, and pH, were measured in temperature range 283.15 to 363.15 K and atmospheric pressure. The effects of temperature, alkyl chain, and anion type on physicochemical properties were investigated. The results revealed that the physicochemical properties decreased as a function of temperature. Unlike viscosity, other properties, such as density, surface tension, refractive index and pH values, decreased, while alkyl chain length increased. Understanding ILs properties and determining their unique abilities helps researchers to use them in new applications. These long alkyl chain ILs, are being used as surfactants to reduce Oil/Water interfacial tension in EOR process.

Implementation of soft computing approaches for prediction of physicochemical properties of ionic liquid mixtures

  • Atashrouz, Saeid;Mirshekar, Hamed;Hemmati-Sarapardeh, Abdolhossein;Moraveji, Mostafa Keshavarz;Nasernejad, Bahram
    • The Korean Journal of Chemical Engineering
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    • v.34 no.2
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    • pp.425-439
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    • 2017
  • The main objective of this study was to develop soft computing approaches for prediction of physicochemical properties of IL mixtures including: density, heat capacity, thermal conductivity, and surface tension. The proposed models in this study are based on support vector machine (SVM), least square support vector machines (LSSVM), and group method of data handling type polynomial neural network (GMDH-PNN) systems. To find the LSSVM and SVM adjustable parameters, genetic algorithm (GA) as a meta-heuristic algorithm was utilized. The results showed that LSSVM is more robust and reliable for prediction of physicochemical properties of IL mixtures. The proposed GA-LSSVM model provides average absolute relative deviations of 0.38%, 0.18%, 0.77% and 1.18% for density, heat capacity, thermal conductivity, and surface tension, respectively, which demonstrates high accuracy of the model for prediction of physicochemical properties of IL mixtures.

Influence of Functionalization on Physicochemical Properties of Multi-walled Carbon Nanotubes/Epoxy Matrix Nanocomposites

  • Seo, Min-Kang;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.30 no.1
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    • pp.124-128
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    • 2009
  • In this study, the effect of multi-step purification or functionalization on physicochemical properties of multi-walled carbon nanotubes (MWNTs)/epoxy (EP) nanocomposites was investigated. The nanocomposites containing multi-step purified MWNTs showed a stronger influence on $T_g$ and increased in mechanical properties in comparison to nanocomposites containing the same amount of only purified MWNTs. Consequently, the multi-step purification of MWNTs led to an improvement of thermomechanical properties of nanocomposites, resulting from improving the intermolecular interaction of MWNTs in epoxy matrix resins.

Identification of Workflow for Potential Contaminants and their Physicochemical Properties (불특정 오염부지에 대한 잠재적 오염물질 선정 및 물리·화학적 특성 정보화)

  • Kim, Yoon Ji;Kim, Youn-Tae;Han, Weon Shik;Lee, Seunghak;Choung, Sungwook
    • Journal of Soil and Groundwater Environment
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    • v.24 no.2
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    • pp.8-22
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    • 2019
  • Among numerous chemicals used globally, the number of emerging contaminants is increasing. Numerical modeling for contaminant fate and transport in the subsurface is critical to evaluate environmental and health risk. In general, such models require physicochemical properties of contaminants as input values, which can be found in numerous chemical databases (DB). However, there exist lack of information specific to recently emerging contaminants, which requires estimation of physicochemical properties using regression programs. The purpose of the study is to introduce the workflow for identifying physicochemical properties of potential contaminants utilizing numerous chemical DBs, which frequently lists up potential contaminants for estimating chemical behavior. In this review paper, details of several chemical DBs such as KISChem, TOXNET, etc. and regression programs including EPI $Suite^{TM}$, ChemAxon, etc. were summarized and also benefit of using such DBs were explained. Finally, a few examples were introduced to estimate predominant phase, removal ratio, partitioning, and eco-toxicities by searching or regressing physicochemical properties.

Physicochemical Properties and Consumer Acceptability of Commercial Gang-jeong (시판 강정류의 이화학적 특성 및 소비자 기호도에 관한 연구)

  • Ryu, Ji-Hye;Kwon, Yong-Suk;Kim, Kyoung-Mi;Lee, Jin-Young
    • Journal of the Korean Society of Food Culture
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    • v.29 no.6
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    • pp.637-647
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    • 2014
  • This study was conducted to examine the physicochemical properties and consumer acceptability of commercial Gang-jeong. The samples used in this study were nine different Gang-jeong as commercial products. To accomplish this research, the physicochemical properties of nine samples, including moisture, crude lipid, sugar contents, acid value, color values, and texture, were measured. In addition, consumer panels evaluated the overall acceptability, appearance, flavor, sweetness, and texture of samples using a 9-point Likert type scale as well as the perceived intensities of sweetness and rancid odor by a 9-point Just-About-Right (JAR) scale. All data were statistically analyzed using One-way ANOVA, Principle Component Analysis, Hierarchical Cluster Analysis, and Pearson's Correlation Analysis. All physicochemical properties were significantly different among the samples (p<0.001). Analyses of consumer acceptability and JAR ratings of the nine samples showed significant differences (p<0.001).

Optimization of Extraction Conditions for Physicochemical Properties of Ethanol Extracts from Chrysanthemum boreale (산국(山菊) 에탄올 추출물의 이화학적 특성에 대한 추출조건의 최적화)

  • 권중호;박난영;이기동;정용진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.4
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    • pp.585-590
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    • 1998
  • To renew interest in Chrysanthemum boreale as a traditional food material, response surface methodology was used for optimizing extraction conditions and monitoring physicochemical properties of ethanol extracts from Chrysanthemum petal. The phenolic compounds of ethanol extracts were minimized in 87ml/g(solvent per sample), 21%(ethanol concentration), and 15 hours(extraction time). The physicochemical properties of ethanol extracts were maximized in the conditions of 115ml/g, 98% and 16 hours on yellow color intensity, 143ml/g, 75% and 19 hours on carotenoid content, and 148ml/g, 53% and 18 hours on soluble solid content. Optimum ranges of extraction condition for physicochemical properties of Chrysanthemum boreale were 130~150ml/g, 70~85% and 20~28 hours, respectively. Predicted values at the optimum extraction condition were in good agreement with experimental values.

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Effects of Packaging Materials on the Physicochemical Characteristics of Seasoned Anchovies During Storage (포장재가 멸치조미가공품의 저장 중 이화학적 품질 특성에 미치는 영향)

  • Lee, Eui-Seok;Lee, Hyong-Ju;Bae, Jae-Seok;Kim, Yong-Kuk;Lee, Jong-Hyeouk;Hong, Soon-Taek
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.4
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    • pp.461-469
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    • 2013
  • This research is performed to investigate the changes in the physicochemical properties and microbial growths of seasoned anchovies with various packaging materials (PET/CPP : polyethylene terephthalate/cast polypropylene, PET/EVOH : polyethylene terephthalate/ethylene-vinyl alcohol, PET/AL/LDPE: polyethylene terephthalate/aluminum/low density polyethylene), which are stored at various temperatures (25, 35, $45^{\circ}C$) for 60 days. Generally, it is being observed that changes in physicochemical properties (i.e., moisture content, color, brown intensity, TBA value, TMA, VBN etc) of seasoned anchovies are significant when stored at higher temperatures. Particularly, the packaging materials are found to influence substantially on the physicochemical properties of seasoned anchovies. With packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e., PET/CPP), the changes in physicochemical properties of seasoned anchovies are significant, while being low with low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). In addition, results of microbial growths in seasoned anchovies show that significant increases in total aerobic bacteria counts (about 100-fold after 60 day of storage) are observed in samples with packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e, PET/CPP), while with only small increases for samples of low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). Based on the changes in the physicochemical properties and results of microbial growths, it is being concluded that PET/EVOH film is suitable for the packaging of seasoned anchovies.

Development of Two-Step Temperature Process to Modulate the Physicochemical Properties of β-lactoglobulin Nanoparticles

  • Ha, Ho-Kyung;Nam, Gyeong-Won;Khang, Dongwoo;Park, Sung Jean;Lee, Mee-Ryung;Lee, Won-Jae
    • Food Science of Animal Resources
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    • v.37 no.1
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    • pp.123-133
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    • 2017
  • The development of a new manufacturing process, a two-step temperature treatment, to modulate the physicochemical properties of nanoparticles including the size is critical. This is because its physicochemical properties can be key factors affecting the cellular uptake and the bioavailability of bioactive compounds encapsulated in nanoparticles. The aims of this study were to produce (beta-lactoglobulin) ${\beta}-lg$ nanoparticles and to understand how two-step temperature treatment could affect the formation and physicochemical properties of ${\beta}-lg$ nanoparticles. The morphological and physicochemical properties of ${\beta}-lg$ nanoparticles were determined using atomic force microscopy and a particle size analyzer, respectively. Circular dichroism spectroscopy was used to investigate the secondary structure of ${\beta}-lg$. The surface hydrophobicity and free thiol groups of ${\beta}-lg$ were increased with a decrease in sub-ambient temperature and an increase in mild heat temperature. As sub-ambient temperature was decreased, a decrease in ${\alpha}-helical$ content and an increase in ${\beta}-sheet$ content were observed. The two-step temperature treatment firstly involved a sub-ambient temperature treatment from 5 to $20^{\circ}C$ for 30 min, followed secondly by a mild heat temperature treatment from 55 to $75^{\circ}C$ for 10 min. This resulted in the production of spherically-shaped particles with a size ranging from 61 to 214 nm. Two-way ANOVA exhibited the finding that both sub-ambient and mild heat temperature significantly (p<0.0001) affected the size of nanoparticles. Zeta-potential values of ${\beta}-lg$ nanoparticles were reduced with increasing mild heat temperature. In conclusion, two-step temperature treatment was shown to play an important role in the manufacturing process - both due to its inducement of the conformational changes of ${\beta}-lg$ during nanoparticle formation, and due to its modulation of the physicochemical properties of ${\beta}-lg$ nanoparticles.

Polyacetylenic compounds from Atractylodes rhizomes

  • Kim, Jung-Hoon
    • The Korea Journal of Herbology
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    • v.31 no.5
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    • pp.25-39
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    • 2016
  • Objectives : Atractylodes rhizomes, which have been widely used to treat gastrointestinal disorders, consist of numerous chemical compounds. Polyacetylenes are the parts of characteristic compounds of importance required to understand the therapeutic properties of Atractylodes rhizomes. It is necessary to understand the physicochemical and pharmacological properties of polyacetylenes in the Atractylodes rhizomes.Methods : The literatures from 1970 to January 2016 were searched using Korean and international electronic databases. The chemical structures of polyacetylenes were drawn by structure-drawing software.Results : The reported polyacetylenes were classified by their chemical skeletons and original resources, and their physicochemical and pharmacological features were discussed. Polyacetylenes with skeletal moieties were reported, such as diene-diyne types (two double and two triple carbon-bonds), triene-diyne types (three double carbon bonds and two triple carbon bonds), and monoene-diyne types (one double carbon bonds and two double carbon bonds), with various functional groups. Atractylodin was most frequently reported from many Atractylodes species. Atractylodin-related polyacetylenes showed chemical instability in both high and freezing temperatures. Processing of the Atractylodes rhizomes by stir-frying with bran could affect the contents of polyacetylenes and their bioavailability in vivo. Several polyacetylenes showed structure-related anti-inflammatory activities and gastrointestinal activities.Conclusion : Polyacetylene compounds in Atractylodes rhizomes were based on three chemical backbones and showed diverse physicochemical and pharmacological features. The present study provides structural, physicochemical, and pharmacological information of polyacetylene from Atractylodes rhizomes. This information provides fundamental data for further research.

The Physicochemical Properties of Hand-Peeled and Flame-Peeled Chestnuts (수작업 박피밤과 화염박피 밤의 물리화학적 특성)

  • 김종훈;박재복;최창현
    • Journal of Biosystems Engineering
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    • v.24 no.5
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    • pp.407-414
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    • 1999
  • To evaluate the quality of flame-peeled chestnuts, their physical and chemical properties were analyzed. The physicochemical properties of flame-peeled chestnuts, including geometrical shape, texture and chemical composition, were compared to those of hand-peeled ones. For the flame-peeled chestnuts, some properties in heated and non-heated sections were separately analyzed. The color, texture such as springness, cohesiveness, adhesiveness, hardness and chewiness, moisture content, and reducing sugar of the heated section of the flame-peeled chestnuts were significantly different with their non-heated section. But the physicochemical properties of the non-heated section of the flame-peeled chestnuts were similar to those of the hand-peeled ones.

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