This study investigated the physical, thermal, rheological, and binding properties of faba bean protein concentrate (FBC) and FBC-anionic gum mixtures. The anionic gums used in this study were sodium alginate (NaA), low-methoxyl amidated pectin (LMA), l-carrageenan (lCA), and gellan gum (GLG). The study found that FBC successfully incorporated the minced textured vegetable protein (TVP), but the formed TVP block had a fragile and soft texture. The water absorption index decreased in FBC-NaA and FBC-LMA mixtures but increased in FBC-lCA and FBC-GLG mixtures. The water solubility index decreased by adding NaA, LMA, and lCA, excluding GLG, to FBC. Adding anionic gums to FBC decreased solubility, while the swelling power was reversed in FBC-anionic gum mixtures, except for the FBC-LMA mixture. The addition of anionic gums to FBC increased melting onset and peak temperatures compared to FBC. The G′ value of FBC and FBC-anionic gum mixtures increased with temperature, indicating their thermogelling characteristic. The hardness of hamburger patties prepared with minced TVP and FBC or FBC-anionic gum mixtures generally tended to increase upon reheating, refrigeration, and reheating after refrigeration. The study concluded that the FBC-anionic gum mixtures have significant potential for binding different types of TVPs, highlighting its practical application.
The spent fuels derived from the nuclear reactor facilities may be finally disposed in a deep underground below 500 m. It majorly has uranium with minor iodine, which is a typical anionic radionuclide. In particular, radioiodine has higher mobility from its spent fuel source. It has been well known that it could freely pass through a compacted bentonite that is one of underground engineering barriers that are used to retard some nuclide’s migration from the spent fuel. We installed a small laboratory apparatus in an anaerobic glove box imitating such an underground repository and evaluated the iodine mobility in compacted bentonites with or without copper. Some copper-bearing bentonites were prepared in two types, a copper ion-exchanged form and a copper nanoparticle-mixed one. In our study, we tried to find an effect of sulfate that has an ability to retard mobile iodine from the compacted bentonite for a long-term period. Conclusively, we found an effective way to limit the iodine release from the compacted bentonite. This condition can be achievable by exchanging the bentonite interlayer cations with copper ions or by simply mixing copper nanoparticles with bentonite powder. In those cases, soluble iodine can be easily immobilized as a solid phase (i.e., marshite (CuI)) by combining with copper via the geochemical role of sulfate and indigenous SRB (sulfate reducing bacteria) of bentonite.
Anionic radionuclides pose one of the highest risks to the long-term safety assessments of disposal repositories. Therefore, techniques to immobilize and separate such anionic radionuclides are of crucial importance from the viewpoints of safety and waste volume reduction. The main objective of this study is to design a separator with minimum pressure disturbance, based on the concept of a conventional cyclone separator. We hypothesize that the anionic radionuclides can be immobilized onto a nanomaterial-based substrate and that the particles generated in the process can flow via water. These particles are denser than water; hence, they can be trapped within the cyclone-type separator because of its design. We conducted particle tracking analysis using computational fluid dynamics (CFD) for the conventional cyclone separator and studied the effects due to the morphology of the separator. The proposed sandglass-like design of the separator shows promising results (i.e., only one out of 10,000 particles escaped to the outlet from the separation zone). To validate the design, we manufactured a laboratory-scale prototype separator and tested it for iron particles; the efficiency was ca. 99%. Furthermore, using an additional magnetic effect with the separator, we could effectively separate particles with ~100% efficiency. The proposed sandglass-like separator can thus be used for effective separation and recovery of immobilized anionic radionuclides.
Carbonaceous materials are considered as potential adsorbents for organic dyes due to their unique structures which provide high aspect ratios, hydrophobic property, large efficient surface area, and easy surface modification. In this work, graphene nanoribbons (GNRs) were prepared by atomic hydrogen-induced treatment of single-walled carbon nanotube (SWCNTs), which inspire the idea of cutting and unzipping the SWCNTs carpets with the modified in molecules prevent because of the unfolding of the side-walls. The unfolded spaces and uniform vertical arrangement not only enhance the active surface area, but also promote the electrostatic and π–π interactions between dyes and GNRs. The improved adsorption capacity of GNRs beyond original SWCNTs can be determined by the adsorption kinetics and isotherm, which are evaluated through adsorption batch experiments of the typical cationic methylene blue (MB) and anionic orange II (OII) dye, respectively. It is shown that the adsorption kinetics follow a pseudo second-order model while the adsorption isotherm could be determined by Langmuir model. The results reveal that the maximum adsorption capacities of GNRs for MB and OII are 280 and 265 mg/g, respectively. The GNRs present the highly efficient, cost effective, and environmental friendly properties for the commercial applications of wastewater treatment.
One- and two-dimensional carbon nanomaterials were tested as adsorbents for the elimination of two anionic dyes, reactive red 2 and methyl orange, and the cationic dye methylene blue from aqueous solutions under the same conditions. Carbon nanomaterials performed well in the removal of dyes. Surface oxygenated groups in the nanomaterials improved the cationic dyes’ adsorption, but not the adsorption of the anionic dye. The interactions between nanomaterials and dyes were verified by infrared and Raman spectroscopy. The pseudo-second order kinetic model was better fitted to the kinetic experimental data than the Elovich and pseudo-first order models. The equilibrium adsorption data were best fitted by the Langmuir model. The dimensions and morphology of the carbon nanomaterials play an important role in the adsorption of the three dyes. The main mechanism of adsorption of anionic dyes is by the interactions of the aromatic rings of the dye structures and π delocalized electrons on carbon nanostructures; the adsorption of cationic dye is mainly due to electrostatic interactions.
본 연구에서는 지방 알코올을 이용하여 탄소 길이에 따른 술폰산계 음이온 계면활성제를 합성하였으며, 합성한 계면활성제들의 구조를 FT-IR과 1H NMR 분석을 통하여 확인하였다. 음이온 계면활성제의 임계미셀농도(critical micelle concentration: cmc)는 10-5∼10-3mol/L이며, 임계미셀농도에서의 표면장력 값은 26∼32 mN/m이었다. 합성한 술폰산계 계면활성제의 분자당 최소 영역값은 1.68∼1.30nm2이다. 음이온 계면활성제의 분자당 최소 영역이 감소하였다. 합성한 계면활성제의 물성은 임계미셀농도, 기포력, 유화력, 접촉각을 측정하였다.
In this study, analyzed the changes occurred after adding casein emulsions to water - dispersed polyurethane using polypropylene glycol (PPG). For this purpose, anionic water - dispersed polyurethane containing PPG, IPDI and DMPA and casein emulsion prepared by dissolving casein in distilled water using ammonia water were prepared. As a result of measuring the alkali resistance by using the prepared resin, there was no change in the physical properties. The tensile strength of the sample having a high casein content was measured to be 2.227 kgf / ㎟. Elongation was measured at 474% for samples containing less casein and The abrasion resistance was measured as 46.090 ㎎.loss of sample containing much casein as a result of the surface roughness measurement.
Detergency and surface active properties of mixed anionic surfactants with amphoteric and nonionic were investigated. Sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate (ADS) as anionic surfactants and cocamidopropyl betaine (CAPB) as an amphoteric surfactant were used. Nonionic surfactants, which are butyl glucoside (BG), octyl glucoside (OG), decyl glucoside (DG), lauryl dimethylamine oxide (AO) and saponin were also used. To study the synergy effects of mixed SDS/ADS anionic surfactant systems, amphoteric and nonionic surfactants were added into the mixed anionic surfactants. Investigated properties of surfactant mixtures were critical micelle concentration (CMC), surface tension (γ), wettability. In addition, based on these properties, detergency of each sample was examined. Surfactant mixtures are anionics (SDS/ADS), anionic/amphoteric/nonionic (SDS/ADS/CAPB/ saponin), and anionic/nonionic (SDS/ADS/BG/saponin, SDS/ADS/OG/saponin, SDS/ADS/ DG/saponin, and SDS/ADS/AO/saponin). With the addition of amphoteric and nonionic to mixed anionic surfactants, CMC and γ were decreased. Addition of CAPB, which is amphoteric, showed the best property at CMC and γ. Furthermore, as the chain length of hydrocarbon in alkyl glucosides was increased, the CMC and γ were enhanced. However, the wettability did not exactly match up with CMC and γ. The surfactant mixture, which contained DG, showed the best performance at wetting time. Detergency was measured at various temperatures (15 oC, 30 oC, 50 oC). The cleaning performance was enhanced by increasing washing temperature. Moreover, detergency was influenced by not only CMC and γ but also wettability. Although CMC and γ were not minimum at surfactant mixture that included DG, the best cleaning performance showed in that sample.
In this study, we developed and validated microanalysis methods for the determination of linear alkylbenzenesulfonate (LAS), sodium lauryl sulfate (SLS), and alpha olefin sulfonate (AOS). The conditions for the analysis of the surfactants using HPLC with FLD, RID, and ELSD detectors were investigated. The methods were validated by determining the linearity, limits of detection (LODs), limits of quantification (LOQs), recovery, precision, and accuracy. LAS analysis by FLD revealed calibration curves that were linear in the range of 10-200 mg/L for an LAS mixture. The calibration curves for C10-C13 had correlation coefficients of 0.995, 0.997, 0.996, and 0.997, respectively. SLS analysis using RID generated a linear calibration curve in the range of 10-300 mg/L. The calibration curve for SLS C12 had a correlation coefficient of 0.9994. AOS analysis using ELSD resulted in a correlation coefficient of 0.9940. For LAS, the LODs and LOQs were 0.09-0.56 and 0.30-1.87 mg/L, respectively. For SLS C12, the LOD and LOQ were 0.07 and 2.33 mg/L, respectively. For AOS C14, the LOD and LOQ were 16.55 and 21.83 mg/L, respectively. The recoveries were 97.17-98.84% for LAS C10-C14, 97.94% for SLS C12, and 96.11% for AOS C14. The established methods provide acceptable precision and accuracy. Our methods could be useful for the detection of anionic surfactants in dishwashing detergents.
We have hybridized Angelic gigas Nakai flower extract (AGNF) and two-dimensional layered double hydroxide (LDH) nanomaterials through reversible dehydration-hydration in order to obtain the nanopowder of natural extract. The Angelica gigas Nakai flower was treated with methanol to extract carbohydrate, polyphenol, and flavonoid components. LDH with an uniform size of 250 nm was prepared by hydrothermal method and calcined at 400ºC to obtain layered double oxide (LDO) precursor. For hybridization, AGNF in 40% methanol was reacted with LDO powder at various AGNF/LDO weight ratios: 0.15, 0.30, 0.85, and 1.70. The hybrids were obtained in fine powder which had enhanced hydrophilicity and water dispersity compared with dried AGNF. The X-ray diffraction and scanning electron microscopic results revealed that the house-of-cards structure of nanomaterials could encapsulate AGNF moiety inside their cavity. Quantitative analyses using UV-Vis spectra exhibited that the content of AGNF in hybrid increased upon AGNF/LDO ratio in reactant increased. According to 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay, AGNF/LDO showed higher antioxidant activity compared with an equivalent amount of AGNF itself.
본 연구에서는 계면활성제 분석법의 개발을 위하여 High performance liquid chromatography-evaporative light scattering detection(HPLC-ELSD) 기기를 이용하여 음이온 및 비이온 계면활성제 중 다소비 계면활성제인 Alkyl polyglucoside(APG)와 Alpha olefin sulfonate(AOS)를 분석하였다. 실험 결과 APG와 AOS 모두 직선성의 상관관계 계수(R2)가 0.99 이상으로 직선성이 양호하였으며, 검출한계는 APG가 2.29 mg/L, AOS가 16.55 mg/L로 나타났고, 정량한계는 APG가 7.63 mg/L, AOS가 55.16 mg/L로 나타났다. 또한, 회수율 검증을 실시한 결과 APG는 99.29%, AOS는 96.11%로 나타나 회수율 100±10% 이내의 검증기준을 모두 만족하였다. 정밀성 및 정확성을 판단한 결과 APG의 정밀성은 상대표준편차 0.30%, 정확성은 0.26-0.52%로 분석되었으며, AOS의 정밀성은 상대표준편차 0.10%, 정확성은 0.01-0.52%로 분석되어 모두 상대표준편차 1.0% 이하의 검증기준에 적합하였다. 확립된 분석법을 주방세제에 적용하여 분석한 결과 샘플 3종 모두에서 APG와 AOS가 각각 검출되었으며, 표준사용량을 기준으로 APG, AOS의 평균 함유량은 각각의 LD50에 크게 미치지 못하는 것으로 나타났다. 따라서 본 연구를 통하여 확립된 음이온 및 비이온 계면활성제의 분석법은 모든 성분에 대해 감응함으로 한가지 검출기를 이용하여 여러성분을 동시에 측정할 수 있어 식기 등의 잔류물질 혹은 식품 중 혼입되어 있는 다양한 계면활성제 함유량 분석에 적용하여 계면활성제의 관리를 위한 기초자료로 활용될 것으로 본다.
폴리아마이드 역삼투막 표면에 음이온 수용성 고분자인 poly(vinyl amine)(PVAm)을 코팅한 후 오염물질인 bovine serum albumin (BSA), humic acid (HA), sodium alginate (SA)에 대하여 파울링 개선효과가 있는지를 알아보고자 하였다. PVAm의 코팅과 파울링 여부는 scanning electron microscopy (SEM)을 통해 관찰하였다. BSA, HA, SA 100 ppm 공급원액을 이용하여 2, 4, 8 bar로 압력을 변화시켜 투과성능실험을 수행한 결과 PVAm으로 코팅되지 않은 막과 코팅된 막 모두 압력증가에 따라 파울링 현상이 심화되었으나 PVAm으로 코팅된 막이 BSA, HA, SA의 경우 모두에서 약 30%이상 투과도가 향상되어 파울링 개선효과가 나타나는 것을 확인할 수 있었다. HA > SA > BSA의 순으로 파울링 개선효과가 나타났으며 HA의 경우 가장 두드러지게 나타났다.
Dye removal from waste water via adsorption by activated carbons (ACs) developed from agricultural wastes represents an ideal alternative to other expensive treatment options. Physical and chemical ACs were prepared from rice husks. The textural properties of the ACs were characterized by Brunauer-Emmett-Teller-N2 adsorption and scanning electron microscopy. The chemistry of the carbon surface was investigated by Fourier transform infrared spectroscopy, base and acid neutralization capacities, pH of the active carbon slurry, and pHpzc. The adsorption capacities of the ACs for the basic dye (methylene blue) and acid dye (acid green 25) were determined using parameters such as contact time, pH, and temperature. NaOH-ACs showed the highest surface area and total pore volume, whereas steam-ACs showed the lowest ones.
본 연구에서는 다공성 polyethylene (PE) 이차전지용 격리막에 poly(ethylenimine) (PEI)을 함침시켜 isophthaloyl dichloride (IPC)을 이용한 가교반응 통하여 음이온교환막을 제조하였다. 제조된 막의 특성화를 평가하기 위하여 함수율, 접촉각, FT-IR, 이온교환용량, 이온전도도 등을 측정하였다. PEI와 IPC의 반응은 아민과 -COCl기와의 반응으로 아마이드기가 생성된다. 이온교환용량의 경우 30초 반응에서 1.96 meq./g dry membrane부터 600초 반응으로 인한 1.14 meq./g dry membrane까지 감소하는 경향을 나타내었고, 이온전도도의 경우 IPC와의 가교시간이 30초일 때 9.15×10-2S/㎝의 높은 값을 나타냄을 확인할 수 있었다.
Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S133D) surfactant was prepared. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 2.0 wt% EU-S133D, silicone dioxide/Acrylate core-shell polymerization was carried out on the surface of silicone dioxide particle without forming the new silicone dioxide particle during acrylate shell polymerization in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).
The inorganic-organic composite particles with core-shell structure were polymerized by using styrene and potassium persulfate (KPS) as a shell monomer and an initiator, respectively. We studied the effect of surfactants on the core-shell structure of silicone dioxide/styrene composite particles polymerized in the presence of sodium dodecyl sulfate(SDS), polyoxyethylene alkylether sulfate (EU-S133D), and at none surfactant condition. We found that SiO2 core / polystyrene(PS) shell structure was formed when polymerization of styrene was conducted on the surface of SiO2 particles, and the concentration SDS and EU-Sl33D was 8.34×10-2mole/L. The core-shell structure was confirmed by measuring the thermal decomposition of the polymer composite using thermogravimetric analyzer (TGA), and the morphology of the composite particles was characterized by transmission electron microscope (TEM).
A CNT-TiO2 nano composite was prepared from titanium chloride (TiCl4) via sol-gel process using multi walled carbon nano tube (MWCNT) followed by calcination at 450℃. Spectral analysis revealed that the formed TiO2 resided on the carbon in anatase form. The effect of adsorption was investigated using aqueous solution of methylene blue and procion blue dye. The photochemical reaction of CNT-TiO2 composite in aqueous suspensions was studied under UV illumination in batch process. The reaction was investigated by monitoring the discoloration of the dyes employing UV-Visible spectro-photometeric technique as a function of irradiation time. The catalyst composites were found to be efficient for the photodegradation of the dye.