산화망간(MnO2)의 비율 변화에 따른 청화의 발색 연구

강 은 종,오창윤 한국도자학회 2019 한국도자학연구 Vol.16 No.1

본 연구는 산화코발트와 산화망간의 특성을 고찰하고 산화망간의 비율 변화에 따른 발색실험을 진행하여 청화 데이터를 구축한 후 도예작업에 적용해봄으로써, 다채로운 청화 색상 표현의 가능성을 모색하는 데 목적이 있다. 산화코발트는 페르시아가 원산지로 고온번조 과정에서 발색이 고르고 깊은 푸른색을 나타내는 특징이 있는데 이를 채화(彩畵)안료로 만든 것이 청화이다. 청화의 회화적 특성을 최초로 도예에 적용한 건 중국 송·원대(宋·元代)의 경덕진요(景德鎭窯) 도공들이었다. 송대(宋代)에 사용된 중국산 청화안료의 경우 산화망간의 함유량이 많고 매우 푸른색으로 발색 되는 페르시아산과 다르게 암갈색 및 흑색을 띠고 있다. 이를 통해 산화망간이 청화의 발색에 영향을 미치고 있음을 유추할 수 있었으며, 그 특성을 활용한다면 도예작업에 다채로운 청화 표현이 가능하리라 판단되었다. 따라서 도예작업에서 널리 사용되고 있는 산화망간의 특성을 이해하고 첨가제로 사용하여 비율 변화에 따라 나타나는 청화의 발색에 중점을 두어 연구를 진행하였다. 연구과정은 첫째, 연구의 중심이 되는 청화의 기원과 특성, 그리고 첨가제로 활용되는 산화망간의 특성을 고찰하였다. 둘째, 실험에 사용할 시편을 동일한 두께와 크기로 제작하고 810℃로 1차 소성하였다. 셋째, 산화망간의 발색실험에 앞서 산화코발트의 비율 변화에 따른 청화 발색실험을 진행하여 이상적 청화 데이터를 도출하였다. 청화 발색실험은 산화코발트에 일정 비율로 변화를 주어 10개의 청화를 만든 후 준비된 시편에 붓을 이용해 횟수와 농도 변화로 구분하여 두 가지 방법으로 진행하였으며, 1250℃로 2차 소성하였다. 소성 결과, 채도와 명도가 다양한 한색(寒色) 계열의 청색이 나타났으며, 산화코발트 비율이 높아짐에 따라 청화안료가 뭉쳐 고르게 퍼지지 않아 뚜렷한 농담(濃淡)변화를 관찰할 수 없었다. 청화 발색실험에서 가장 이상적 발색을 보인 시편의 조성비는 백색자기토 100 : 산화철 7 : 산화코발트 5였으며, 이를 기본 청화 데이터로 구축하였다. 넷째, 도출한 기본 청화 데이터에 산화망간의 비율변화에 따른 발색실험을 진행하여 청화 데이터를 도출하였다. 실험 결과, 산화망간의 비율이 높아질수록 채도와 명도가 낮아졌고 산화망간이 융제 및 착색제 역할을 하여 전체적으로 뭉침 없이 부드럽고 차분하게 발색됨을 알 수 있었다. 또한 물에 잘 녹지 않는 산화망간의 특성으로 인하여 그 비율이 높아질수록 반점의 수가 증가하는 특징이 나타났다. 채도와 명도가 낮아지면서 한국화에서 사용하는 먹(墨)과 흡사한 색을 띠었고, 실험을 통해 도출한 다양한 시료를 사용하여 채화(彩畵)한다면 보다 다양한 청화의 색상 표현이 가능하지 않을까 하는 생각이 들었다. 전체 실험과정의 시편분석을 통해 가장 이상적인 발색을 보인 시편을 청화시료로 도출하여 데이터를 구축하였다. 가장 이상적인 발색을 보인 시편은 6번 시편(백색자기토 100 : 산화철 7 : 산화코발트 5 : 산화망간 25)이었으나 도예작업으로 적용하는 데 있어 다양한 색상 유도를 위하여 한 가지 표준데이터가 아닌 두 가지 데이터를 함께 도출하였다. 이는 단색의 청화표현이 아닌, 다양한 색상변화 적용을 통해 도예작업에서 회화표현의 가능성을 모색하기 위함이다. 마지막으로 산화망간의 비율 변화에 따른 청화 발색실험으로 도출한 청화시 ... The purpose of this study is to investigate the unique characteristics of cobalt oxide and manganese oxide as well as color formation by varying the ratio of manganese oxide in order to develop coloring data and apply them onto ceramics and to address the possibilities of expressing a wide range of white and blue. Cobalt oxide, originated from Persia, has a feature of even and deep blue color due to the high-temp firing process, and it is used for a coloring pigment for the white and blue drawing. The Chinese potters of the Song Dynasty and the Yuan Dynasty were the first one applying the painting characteristics of the white and blue drawing onto ceramics. In the case of the pigment used for the white and blue drawing during the Song Dynasty, its content of manganese oxide was high and had hues of dark brown and black, unlike of the Persian pigment which was bright blue. Therefore, it could conclude that the content of manganese oxide has an influence on the color formation of the white and blue drawing and if it is used properly, it would be able to express various blue colors on ceramics Thus, this study was designed to understand the properties of manganese oxide, widely used in pottery works, and focus on color formation of the white and blue drawing by varying the ratio of manganese oxide. For the first part of this study, the origin and characteristics of the white and blue drawing, a subject of this study, were investigated along with of manganese oxide, used as an additive. Second, specimens, having the same thickness and size, were sintered at 810℃ primarily. Third, prior to the coloration test of manganese oxide, the cobalt oxide coloration test was executed by changing the ratio of cobalt oxide to have the ideal blue color data. For the cobalt oxide coloration test, 10 specimens were prepared first. Then, varying the ratio of cobalt oxide by changing the no. of brush application or varying the concentration and the specimens were sintered at 1250℃ secondarily. After the sintering, blue in the system of cold color was appeared and its brightness and chroma were highly varied. However, with an increase in the ratio of cobalt oxide, there were more lumps so it was not possible to observe a distinctive change in shade. The composition ratio of the specimen with the most ideal color formation was white porcelain 100: iron oxide 7: and cobalt oxide 5, and it was used as the basic blue coloring data. Fourth, the coloration test was executed by varying the ratio of manganese oxide to have the data on the blue and white drawing. From the test, it was shown that with the increased ratio of manganese oxide, the chroma and brightness decreased and the no. of spots also increased. In addition, since manganese oxide acted as a flux and a coloring agent, the entire hue was somewhat soft and calm without lumps. Also, due to the insolubility of manganese oxide, the no. of spots increased with the increased ratio of manganese oxide. As the chroma and brightness became lower, it became similar with the ink stick, generally used for Korean paintings. So, it would be possible to express more various colors of blue by using various pigments. Through the analysis of entire specimens, the specimen with the most ideal color was chosen as the sample. The specimen with the most ideal color was the no. 6 (white porcelain 100: iron oxide 7: cobalt oxide 5: manganese oxide 25), but to have a wide range of color on ceramics, two data were created, instead of one. It was to investigate the possibility of painting expressions through application of various colors rather than solely for the white and blue drawing in which a single color is used. For the last, by applying three pigments, created from the color formation test in which the ratio of manganese oxide was varied, on actual ceramics, it evaluated and suggested the possibility of expression of a wide range of colors in the white and blue drawing.

Synthesis and Electrochemical Characterization of Reduced Graphene Oxide-Manganese Oxide Nanocomposites

Lee, Yu-Ri,Song, Min-Sun,Lee, Kyung-Min,Kim, In-Young,Hwang, Seong-Ju The Korean Electrochemical Society 2011 Journal of electrochemical science and technology Vol.2 No.1

Nanocomposites of reduced graphene oxide and manganese (II,III) oxide can be synthesized by the freeze-drying process of the mixed colloidal suspension of graphene oxide and manganese oxide, and the subsequent heat-treatment. The calcined reduced graphene oxide-manganese (II,III) oxide nanocomposites are X-ray amorphous, suggesting the formation of homogeneous and disordered mixture without any phase separation. The reduction of graphene oxide to reduced graphene oxide upon the heat-treatment is evidenced by Fourier-transformed infrared spectroscopy. Field emission-scanning electronic microscopy and energy dispersive spectrometry clearly demonstrate the formation of porous structure by the house-of-cards type stacking of reduced graphene oxide nanosheets and the homogeneous distribution of manganese ions in the nanocomposites. According to Mn K-edge X-ray absorption spectroscopy, manganese ions in the calcined nanocomposites are stabilized in octahedral symmetry with mixed Mn oxidation state of Mn(II)/Mn(III). The present reduced graphene oxide-manganese oxide nanocomposites show characteristic pseudocapacitance behavior superior to the pristine manganese oxide, suggesting their applicability as electrode material for supercapacitors.

Effects of oxidative coupling reaction of 4-chlorophenol with manganese oxide on the phenanthrene sorption

Ko, Seok-Oh,Jun, Sun-Young,Lee, Do-Hoon,Park, Jaewoo,Shin, Won-Sik Taylor Francis 2007 Journal of Environmental Science and Health. Part Vol.42 No.3

<P> The objective of this study was to evaluate the abiotic transformation rate of 4-chlorophenol (4-CP) by manganese oxide. Sorption and desorption characteristics of polycyclic aromatic hydrocarbons (PAHs) on manganese oxide were also investigated in the presence of 4-CP. Results show that manganese oxide is effective for the transformation of 4-CP and initial reaction rate is the first-order with respect to the 4-CP and manganese oxide. Also, 4-CP transformation rates by manganese oxide are highly dependent upon solution pH and concentration of humic acid. At pH near the point of zero charge (PZC) of manganese oxide, the maximum reaction rate of 4-CP was observed. Sorption of phenanthrene on manganese oxide is significantly increased as a result of 4-CP transformation and subsequent generation of byproducts. Also, sorbed phenanthrene on manganese oxide in the presence of 4-CP showed high degree of desorption resistance.</P>

Unilamellar Nanosheet of Layered Manganese Cobalt Nickel Oxide and Its Heterolayered Film with Polycations

Oh, Eun-Jin,Kim, Tae Woo,Lee, Kyung Min,Song, Min-Sun,Jee, Ah-Young,Lim, Seung Tae,Ha, Hyung-Wook,Lee, Minyung,Choy, Jin-Ho,Hwang, Seong-Ju American Chemical Society 2010 ACS NANO Vol.4 No.8

<P>The exfoliation of layered Li[Mn<SUB>1/3</SUB>Co<SUB>1/3</SUB>Ni<SUB>1/3</SUB>]O<SUB>2</SUB> into individual monolayers could be achieved through the intercalation of quaternary tetramethylammonium (TMA<SUP>+</SUP>) ions into protonated metal oxide. An effective exfoliation occurred when the TMA<SUP>+</SUP>/H<SUP>+</SUP> ratio was 0.5−50. Reactions outside this range produced no colloidal suspension, but all the manganese cobalt nickel oxides precipitated. Atomic force microscopy and transmission electron microscopy clearly demonstrated that exfoliated manganese cobalt nickel oxide nanosheets have a nanometer-level thickness, underscoring the formation of unilamellar nanosheets. The maintenance of the hexagonal atomic arrangement of the manganese cobalt nickel oxide layer upon the exfoliation was confirmed by selected area electron diffraction analysis. According to diffuse reflectance ultraviolet−visible spectroscopy, the exfoliated manganese cobalt nickel oxides displayed distinct absorption peaks at ∼354 and ∼480 nm corresponding to the d<I>−</I>d transitions of octahedral metal ions, which contrasted with the featureless spectrum of the pristine metal oxide. In the light of zeta potential data showing the negative surface charge of manganese cobalt nickel oxide nanosheets, a heterolayered film of manganese cobalt nickel oxide and conductive polymers could be prepared through the successive coating process with colloidal suspension and polycations. The UV−vis and X-ray diffraction studies verified the layer-by-layer ordered structure of the obtained heterolayered film, respectively.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-8/nn100286u/production/images/medium/nn-2010-00286u_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn100286u'>ACS Electronic Supporting Info</A></P>

Porous manganese oxide nanospheres for pseudocapacitor applications

Singu, B.S.,Yoon, K.R. Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.695 No.-

<P><B>Abstract</B></P> <P>Mesoporous, uniform manganese oxide nanosphere thin films were grown on a stainless-steel substrate using the successive ionic layer adsorption and reaction (SILAR) method. The amorphous manganese oxide nanosphere thin films (AMONTFs) were characterized by grazing incidence X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The GI-XRD analysis reveals that the manganese oxide nanosphere thin films were present in the forms of α-MnO<SUB>2</SUB> and γ-MnO<SUB>2</SUB>. XPS demonstrates that the thin films contain a mixture of manganese oxides: MnO<SUB>2</SUB> (Mn<SUP>4+</SUP>) and MnOOH (Mn<SUP>3+</SUP>). The effect of the number of SILAR cycles on the morphology was observed systemically by FE-SEM and greatly influences the size of these unique nanospheres. The electrochemical properties of the AMONTF electrodes were analyzed by cyclic voltammetry (CV) and the galvanostatic charge-discharge (CD) method. The outcomes of the FE-SEM and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere size distribution and large specific capacitance. The manganese oxide thin films exhibit a maximum specific capacitance, energy, and power density of 262.0 F g<SUP>−1</SUP>, 18.3 Wh kg<SUP>−1</SUP>, and 7999.4 W kg<SUP>−1</SUP>, respectively, in an aqueous 1 M Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte solution.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of porous manganese oxide nanosphere thin films. </LI> <LI> The size of the nanospheres well depended on the number of SILAR cycles. </LI> <LI> Maximum specific capacitance of manganese oxide nanosphere thin films showing around 262.0 F g<SUP>−1</SUP>. </LI> </UL> </P>

Exfoliated graphene-manganese oxide nanocomposite electrode materials for supercapacitor

Singu, Bal Sydulu,Yoon, Kuk Ro Elsevier 2019 Journal of alloys and compounds Vol.770 No.-

<P><B>Abstract</B></P> <P>In this paper, one-pot approach was used to produce the highly exfoliated reduced graphene oxide-manganese oxide nanocomposites (rGO-MnO<SUB>x</SUB> and rGO-Mn<SUB>3</SUB>O<SUB>4</SUB>) and systematically analyzed by spectral, thermal, elemental and electron microscope. From the FE-SEM analysis confirms the exfoliated reduced graphene oxide-manganese oxide nanocomposites formation. In the nanocomposites, manganese oxide nanoparticles present in the spherical (rGO-Mn<SUB>3</SUB>O<SUB>4</SUB>), spherical and cube shape (rGO-MnO<SUB>x</SUB>). The electrochemical properties of the rGO-MnO<SUB>x</SUB> and rGO-Mn<SUB>3</SUB>O<SUB>4</SUB> nanocomposites were analyzed by cyclic voltammetry and charge-discharge study. The highly exfoliated rGO-MnO<SUB>x</SUB> nanocomposite show the higher electrochemical capacitive responsive than rGO-Mn<SUB>3</SUB>O<SUB>4</SUB> nanocomposite. The rGO-MnO<SUB>x</SUB> nanocomposite exhibiting the utmost capacitance of 398.8 F g<SUP>−1</SUP> at a sweep rate of 5 mV s<SUP>−1</SUP>, the energy density of 23.3 Wh kg<SUP>−1</SUP> and power density of 2001 W kg<SUP>−1</SUP>, owing to the synergistic effect of reduced graphene oxide and spherical and cubical shape of manganese oxide nanoparticles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Exfoliated reduced graphene oxide-manganese oxide nanocomposites are prepared. </LI> <LI> The rGO-MnO<SUB>x</SUB> nanocomposite exhibiting the utmost capacitance of 398.8 F g<SUP>−1</SUP>. </LI> <LI> The rGO-MnO<SUB>x</SUB> has showing the capacitance retention of 80% over 5000 cycles. </LI> </UL> </P>

Electrodeposition of Mn-Ni Oxide/PEDOT and Mn-Ni-Ru Oxide/PEDOT Films on Carbon Paper for Electro-osmotic Pump Electrode

Baek, Jaewook,Shin, Woonsup The Korean Electrochemical Society 2018 Journal of electrochemical science and technology Vol.9 No.2

$MnO_2$, a metal oxide used as an electrode material in electrochemical capacitors (EDLCs), has been applied in binary oxide and conducting polymer hybrid electrodes to increase their stability and capacitance. We developed a method for electrodepositing Mn-Ni oxide/PANI, Mn-Ni oxide/PEDOT, and Mn-Ni-Ru oxide/PEDOT films on carbon paper in a single step using a mixed bath. Mn-Ni oxide/PEDOT and Mn-Ni-Ru oxide/PEDOT electrodes used in an electro-osmotic pump (EOP) have shown better efficiency compared to Mn-Ni oxide and Mn-Ni oxide/PANI electrodes through testing in water as a pumping solution. EOP using a Mn-Ni-Ru oxide/PEDOT electrode was also tested in a 0.5 mM $Li_2SO_4$ solution as a pumping solution to confirm the effect of the $Li^+$ insertion/de-insertion reaction of Ruthenium oxide on the EOP. Experimental results show that the flow rate increases with the increase in current in a 0.5 mM $Li_2SO_4$ solution compared to that obtained when water was used as a pumping solution.

Electrochemical properties of Mn-doped activated carbon aerogel as electrode material for supercapacitor

이윤재,박해웅,박선영,송인규 한국물리학회 2012 Current Applied Physics Vol.12 No.1

Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde, and it was activated with KOH to obtain activated carbon aerogel (ACA). Specific capacitance of carbon aerogel and activated carbon aerogel was measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Activated carbon aerogel showed higher specific capacitance than carbon aerogel (136 F/g vs. 90 F/g). In order to combine excellent electrochemical performance of activated carbon aerogel with pseudocapacitive property of manganese oxide, 7 wt%manganese oxide was doped on activated carbon aerogel by an incipient wetness impregnation method. For comparison, 7 wt% manganese oxide was also doped on carbon aerogel by an incipient wetness impregnation method. It was revealed that 7 wt% Mn-doped activated carbon aerogel (Mn/ACA) showed higher specific capacitance than 7 wt% Mn-doped carbon aerogel (Mn/CA) (168 F/g vs. 98 F/g). The enhanced capacitance of 7 wt% Mn-doped activated carbon aerogel was attributed to the outstanding electric properties of activated carbon aerogel as well as the faradaic redox reactions of manganese oxide. Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde, and it was activated with KOH to obtain activated carbon aerogel (ACA). Specific capacitance of carbon aerogel and activated carbon aerogel was measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Activated carbon aerogel showed higher specific capacitance than carbon aerogel (136 F/g vs. 90 F/g). In order to combine excellent electrochemical performance of activated carbon aerogel with pseudocapacitive property of manganese oxide, 7 wt%manganese oxide was doped on activated carbon aerogel by an incipient wetness impregnation method. For comparison, 7 wt% manganese oxide was also doped on carbon aerogel by an incipient wetness impregnation method. It was revealed that 7 wt% Mn-doped activated carbon aerogel (Mn/ACA) showed higher specific capacitance than 7 wt% Mn-doped carbon aerogel (Mn/CA) (168 F/g vs. 98 F/g). The enhanced capacitance of 7 wt% Mn-doped activated carbon aerogel was attributed to the outstanding electric properties of activated carbon aerogel as well as the faradaic redox reactions of manganese oxide.

A Composite Formation Route to Well‐Crystalline Manganese Oxide Nanocrystals: High Catalytic Activity of Manganate–Alumina Nanocomposites

Kim, Tae Woo,Yoo, Hana,Kim, In Young,Ha, Hyung‐,Wook,Han, Ah Reum,Chang, Jong‐,San,Lee, Ji Sun,Hwang, Seong‐,Ju WILEY‐VCH Verlag 2011 Advanced Functional Materials Vol.21 No.12

<P><B>Abstract</B></P><P>Manganese oxide nanocrystals are combined with aluminum oxide nanocrystals to improve their crystallinity via calcination without a significant increase of crystal size. A nanocomposite, consisting of two metal oxides, can be synthesized by the reaction between permanganate anions and aluminum oxyhydroxide keggin cations. The as‐prepared manganese oxide–aluminum oxide nanocomposite is X‐ray amorphous whereas heat‐treatment gives rise to the crystallization of an <I>α</I>‐MnO<SUB>2</SUB> phase at 600 °C and Mn<SUB>3</SUB>O<SUB>4</SUB>/Mn<SUB>2</SUB>O<SUB>3</SUB> and <I>γ</I>‐Al<SUB>2</SUB>O<SUB>3</SUB> phases at 800 °C. Electron microscopy and N<SUB>2</SUB> adsorption‐desorption‐isotherm analysis clearly demonstrate that the as‐prepared nanocomposite is composed of a porous assembly of monodisperse primary particles with a size of ∼20 nm and a surface area of >410 m<SUP>2</SUP> g<SUP>−1</SUP>. Of particular interest is that the small particle size of the as‐prepared nanocomposite is well‐maintained up to 600 °C, a result of the prevention of the growth of manganate grains through nanoscale mixing with alumina grains. The calcined nanocomposite shows very‐high catalytic activity for the oxidation of cyclohexene with an extremely high conversion efficiency of >95% within 15 min. The present results show that the improvement of the crystallinity without significant crystal growth is very crucial for optimizing the catalytic activity of manganese oxide nanocrystals.</P>

Synthesis of cobalt oxide-manganese oxide on activated carbon electrodes for electrochemical capacitor application using a liquid phase plasma method

Lee, H.,Kim, B.H.,Park, Y.K.,An, K.H.,Choi, Y.J.,Jung, S.C. Pergamon Press ; Elsevier Science Ltd 2016 International journal of hydrogen energy Vol.41 No.18

<P>An Electrochemical capacitor electrode material was prepared by precipitating cobalt-manganese oxide nanoparticles on the surface of activated carbon powder (ACP) using a liquid phase plasma method. Polycrystalline spherical 100-170 nm-sized metal oxide nanoparticles were precipitated onto the ACP surface with a high degree of uniformity. The initial concentration of precursor influenced the composition of the precipitated nanoparticles. The nanoparticles were bimetallic oxide nanoparticles composed mainly of Co2+ and Mn3+. Increases in the amount of metal oxide nanoparticles precipitated on ACP, were accompanied by reduced specific surface area, average pore size, and total pore volume, as well as by increased specific capacitance. The metal oxide nanoparticles improved the cyclic stability of the electrochemical capacitor and reduced equivalent series resistance. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.</P>