• 한국염색가공학회지
• /
• 제27권3호
• /
• pp.210-218
• /
• 2015

In this study, natural substance and mineral materials was used for architectural interior wallpaper. Because natural substance and minerals are environment-friendly material with moisture adsorption and desorption properties. Natural substance and mineral materials was evaluated in moisture adsorption and desorption properties. Also, in the diatomite, the pores were observed on SEM photographs. Thus, it is supposed that moisture adsorption and desorption properties were influenced by the microstructure of the pore. The wallpaper according to the ratio of the mixture was analyzed for physical properties and moisture adsorption & desorption properties. As a result, we developed a wallpaper having excellent hygrothermal performance.

• 한국환경과학회지
• /
• 제8권1호
• /
• pp.69-74
• /
• 1999

Soil properties which affect the retention of Pb(I) were investigated in the laboratory. It was determined, through selective removal, that organic matter and Fe-oxides are of lesser importance in influencing Pb retention than are soil clay minerals. The following trend : clays ＞ organic matter ＞ Fe-oxides represents the relative importance of each constituent in the adsorption of Pb by soils. The consistently greater Pb uptake by surface over subsurface samples was apparently due to differences in organic matter content, inasmuch as organic matter removal from both resulted in similar adsorption characteristics. All five soils stooled exhibited a pH-dependent trend of adsorption. The extent of Pb adsorption was least at low pH values(4~5), was maximum in the neutral pH range, and leveled off or diminished under more alkaline conditions. There was no strong correlation between Pb uptake and soil cation exchange capacity as routinely measured by the NH$_4$OAc method. A knowledge of clay mineralogy in conjunction with soil pH is suggested as being the most reliable guide to predicting Pb retention by soils.

• Carbon letters
• /
• 제2권1호
• /
• pp.15-21
• /
• 2001

In this work, activated carbon fibers (ACFs) were plated with copper metal using electroless plating method and the effects of surface properties and pore structures on chromium adsorption properties were investigated. Surface properties of ACFs have been characterized using pH and acid/base values. BET data with $N_2$ adsorption were used to obtain the structural parameters of ACFs. The electroless copper plating did significantly lead to a decrease in the surface acidity or to an increase in the surface basicity of ACFs. However, all of the samples possessed a well-developed micropore. The adsorption capacity of Cr(III) for the electroless Cu-plated ACFs was higher than that of the as-received, whereas the adsorption capacity of Cr(VI) for the former was lower than that of the latter. The adsorption rate constants ($K_1$, $K_2$, and $K_3$) were also evaluated from chromium adsorption isotherms. It was found that $K_1$ constant for Cr(III) adsorption depended largely on surface basicity. The increase of Cr(III) adsorption and the decrease of Cr(VI) adsorption were attributed to the formation of metal oxides on ACFs, resulting in increasing the surface basicity.

• 한국재료학회지
• /
• 제14권3호
• /
• pp.229-234
• /
• 2004

All the applications of natural zeolites make use of one or more of their physical and chemical properties: adsorption, ion-exchange and related molecular sieve properties, dehydration and rehydration, and siliceous composition. Accordingly, the applications of zeolite have been carried out in the various aspects because of its large cation exchange capacity and adsorption properties. In this paper, the adsorption effect of heavy metal ions in wastewater on zeolite mineral by batch adsorption process is studied. The amounts of adsorbed ions were variable by original pH and ionic concentration, especially original pH of solution had an important effect on the adsorption. In case of low pH solution, e.g. below 3.0, clinoptilolite adsorbed $Pb^{2+}$ ,$ Cd ^{2+ }$ , $Cu^{2+}$ and $Zn^{ 2+}$ , but mordenite almost did not adsorb except $Pb^{2+}$ . Under the same conditions, these ions were more adsorbed on clinoptilolite than on mordenite mineral. The velocity of adsorption was relatively fast and it was confirmed by shaking test that the equilibrium of adsorption could be attained in about one hour. The species of exchangeable cation of zeolite had an effect on its removing ability and zeolite of the sodium-exchanged type was the best.

• 한국분말재료학회지
• /
• 제24권6호
• /
• pp.483-488
• /
• 2017

Transition-metal oxide semiconductors have various band gaps. Therefore, many studies have been conducted in various application fields. Among these, methods for the adsorption of organic dyes and utilization of photocatalytic properties have been developed using various metal oxides. In this study, the adsorption and photocatalytic effects of $WO_3$ nanomaterials prepared by hydrothermal synthesis are investigated, with citric acid added in the hydrothermal process as a structure-directing agent. The nanostructures of $WO_3$ are studied using transmission electron microscopy and scanning electron microscopy images. The crystal structure is investigated using X-ray diffraction patterns, and the changes in the dye concentrations adsorbed on $WO_3$ nanorods are measured with a UV-visible absorption spectrophotometer based on Beer-Lambert's law. The methylene blue (MB) dye solution is subjected to acid or base conditions to monitor the change in the maximum adsorption amount in relation to the pH. The maximum adsorption capacity is observed at pH 3. In addition to the dye adsorption, UV irradiation is carried out to investigate the decomposition of the MB dye as a result of photocatalytic effects. Significant photocatalytic properties are observed and compared with the adsorption effects for dye removal.

• Carbon letters
• /
• 제4권1호
• /
• pp.21-23
• /
• 2003

In this work, the effect of anodic oxidation treatment on Cr(VI) ion adsorption behaviors of activated carbon fibers (ACFs) was investigated. The aqueous solutions of 10 wt% $H_3PO_4$ and $NH_4OH$ were used for acidic and basic electrolytes, respectively. Surface characteristics and textural properties of ACFs were determined by XPS and $N_2$ adsorption at 77 K. The heavy metal adsorption of ACFs was conducted by ICP. As a result, the adsorption amount of the anodized ACFs was improved in order of B-ACFs > A-ACFs > pristine-ACFs. In case of the anodized treated ACFs, the specific surface area was decreased due to the pore blocking or pore destroying by acidic electrolyte. However, the anodic oxidation led to an increase of the Cr(VI) adsorption, which can be attributed to an increase of oxygen-containing functional groups, such as, carboxylic, lactonic, and phenolic groups. It was clearly found that the Cr(VI) adsorption was largely influenced by the surface functional groups, in spite of the reduced specific surface area of the ACFs.

• 한국세라믹학회지
• /
• 제43권12호
• /
• pp.846-851
• /
• 2006

This paper discuss the adsorption and fluidity properties of recycled cement powder with different hydration hysteresis and particle size. Reactivity of hydrated fine powder was negligible low. Therefore, the adsorption and fluidity properties with super-plasticizer for hydrated recycled cement powder was very important for using additive material. Adsorption amount of super-plasticizer was increased by the finer hydrated recycled cement powder addition. And the fluidity of hydrated recycled cement powder was very poor than un-hydrated cement powder. To Improve the fluidity of hydrated recycled cement powder, PC super-plasticizer is the more effective than NS super-plasticizer.

• 한국광물학회지
• /
• 제18권3호
• /
• pp.183-194
• /
• 2005

일본의 묘기 광상에서 산출되는 벤토나이트를 대상하여 광물학적, 물리화학적 성질 및 열적성질을 측정하였으며, 이 연구의 주목적은 악틴족 원소인 U, Th과 란탄족 원소인 Ce, Eu에 대해 천연산 Na-형 벤토나이트의 흡착특성을 파악하기 위함이다 묘기 벤토나이트는 pH 10.4 정도로 높은 알카리성을 나타낸다. 또한 높은 점도, 팽윤도, CEC 값을 나타내고, 수용액과의 반응에서 짧은 시간에 안정화되어 균질한 상태를 유지하였다. 화학성분 분석결과 $Na_2O$가 CaO에 비해 상대적으로 높은 함량비를 보이는 것으로 보아 묘기 벤토나이트를 구성하는 스멕타이트는 Na-형에 속한다. 열분석 결과 벤토나이트의 전암시료와 점토입자 이하 시료는 각각 $591^{\circ}C$와 $658^{\circ}C$에서 분해됨이 확인되었다. 점토입자 시료 0.2g을 U. Th, Ce그리고 Eu의 각 여러 농도별, pH별 용액 20mL와 반응시킨 흡착실험을 행하였다. 그 결과, 농도 및 pH변화에 따른 흡착량의 변화는 Ce, Th과 Eu용액의 경우 비교적 일정한 흡착량의 감소를 보이나, U용액은 농도가 높아질수록, pH가 증가될수록 급격한 흡착량의 감소를 나타내었다. 흡착능력은 Ce, Th, Eu, U 순으로 나타난다. 벤토나이트의 Ce, Eu, Th, U 흡착은 스멕타이트의 양이온교환반응과 표면흡착반응 이외에도 수용액에 존재하는 이온들이 다양한 화학종의 형성과 침전물 형성이 흡착에 큰 영향을 끼치는 것으로 판단된다. 또한 수반되는 제올라이트가 이들 원소들의 흡착에 영향을 끼쳤을 것이다.

• Bulletin of the Korean Chemical Society
• /
• 제31권6호
• /
• pp.1638-1642
• /
• 2010

Mesoporous carbon CMK-3s with different textural properties have been used for the adsorption of phenol to understand the necessary physicochemical properties of carbon for the efficient removal of phenol from contaminated water. The kinetic constants (both pseudo-second order and pseudo-first-order kinetics) increase with increasing pore size of carbons. The maximum adsorption capacities correlate well with micropore volume compared with surface area or total pore volume even though large pore (meso or macropore) may contribute partly to the adsorption. The pore occupancies also explain the importance of micropore for the phenol adsorption. For efficient removal of phenol, carbon adsorbents should have large micropore volume and wide pore size for high uptake and rapid adsorption, respectively.

• Journal of the Korean Wood Science and Technology
• /
• 제31권5호
• /
• pp.35-42
• /
• 2003

본 연구는 전보(정 등, 2002)에서 제조된 직물유리섬유 강화집성재의 박리 및 수분 흡착특성을 조사해 보기 위해서 실시되었다. 침지 박리시험에서, 3가지 형태의 소재 모두 박리를 나타내지 않았지만, control재를 제외한 모든 형태의 소재는 삶음 박리에서 박리가 발생하였다. 수분흡착시험은 40℃, 상대습도 90% 조건에서 48시간동안 실시하였다. 횡단면 흡습성은 모든 소재에서 다르지 않았다. 유리섬유로 된 소재에서 방사단면과 접선단면은 control재와 비교하여 수분 흡착이 지연되었다. 수분흡착 이방성에서, 유리섬유 함입된 소재는 적은 수분흡착을 나타내었다.