• 한국응용과학기술학회지
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• 제23권4호
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• pp.280-289
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• 2006

Multilayer adsorptions and BET adsorption are analyzed statistical-mechanically. Which ensemble is selected for the analysis is unimportant, because each ensemble yields the same results. However, the amount of mathematical manipulations and the matter of convenience vary from ensemble to ensemble. Hence, multilayer adsorptions and BET adsorption are examined using a canonical and a grand canonical ensembles, and an ensemble of subsystems. Also, the characteristics of multilayer and BET adsorptions are delineated.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.87-94
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• 1997

One of the general properties of adsorption on multilayer is that the amount of adsorbing particles is not saturated. As another important property, in many cases, the amount of adsorbed particles is linearly proportional to the pressure of gases above the layers, at sufficiently low pressure, which is known to be Henry's experimental law. A purpose of this paper is to show qualitatively, in terms of a theory, that an adsorption on multilayer lbeys Henry's law at the region of low pressure. For this, we introduce a simple multilayer adsorption model and establish an adsorption isotherm for the given model, which is analyzed in the limit of low pressure.

• 한국표면공학회지
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• 제27권6호
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• pp.335-339
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• 1994

The underpotential deposition of zinc was investigated on carbon steel and nickel. The relationship be-tween the deposition potentials and the corresponding amounts of charge for deposited layers shows a very similar trend to the multilayer adsorption mechanism. The experimental results fit a mathematical model de-rived on the basis of the BET equation for the underpotential deposition.

• Bulletin of the Korean Chemical Society
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• 제1권4호
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• pp.117-121
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• 1980

The effect of lateral intermolecular interactions among the adsorbate molecules has been incorporated into the theory of multilayer physical adsorption developed previously by the present authors within the frame of Bragg-Williams approximation and the resulting adsorption isotherm has been used to interpret the adsorption data of tetramethylsilane vapor on clean iron film which we failed to account for in our previous works. The result has shown that up to the point where the relative pressure is about 0.7 considerable improvement is obtained but beyond this point there still remains large difference between theoretical and experimental isotherm. Such difference is supposed to arise from the neglect of effect of vertical interaction between the adsorbate molecules and the adsorbent surface.

• 폴리머
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• 제29권4호
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• pp.392-398
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• 2005

Layer-by-layer(LbL) 흡착에 의한 poly(ethylene-alt-m미? anhydride) (PEMAh)/poly(4-vinyl pyridine) (P4VP) 자기조립 다층박막을 제조하였다. 자기조립 다층막을 이루는 PEMAh/P4VP 두 고분자 사이의 수소 결합과 정전기적 인력이 다층막을 이루는 원동력이라는 것이 푸리에 변환 적외선(FT-IR) 분광분석에 의해서 확인되었다. 다층막의 균일한 자기조립 과정은 PEMAh/P4VP 이중층막의 적층 수 증가에 따른 UV-vis 스펙트럼의 256 nm에서 나타나는 P4VP 특성 흡수 피크의 선형적 증가에 의해서 확인할 수 있었다. 다층막을 이루는 고분자 전해질 담지 용액의 조건 변화가 다층막 형성에 미치는 영향을 살펴보기 위하여 두 고분자 용액의 농도 및 PEMAh 담지용액의 pH를 변화시키면서 다층막을 제조하였다. 다층막의 두께, 흡착된 고분자 전해질 질량 및 표면 거칠기의 변화를 UV-vis 분광 분석, 수정진동자 미량저울(quartz crystal microbalance;QCM) 및 원자 힘 현미경(atomic force microscopy;AFM)을 이용하여 측정하였다.

• 대한화학회지
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• 제22권2호
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• pp.78-85
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• 1978

이 論文에서는 著者들이 앞서 發展시킨 多分子層物理吸着理論을 修正하여 새로운 吸着理論을 提案하였다. 이 새로운 理論을 여러가지 adsorbent-adsorbate 系에 適用시켜 본 결과 Type Ⅱ와 Type Ⅲ 吸着의 경우에는 理論置와 實驗置가 잘 一致하였다. 뿐만 아니라 이미 발표한 理論으로써는 설명할 수 없었던 Type Ⅰ 吸着等溫式도 새로운 理論으로는 說明할 수 있었다. 이 理論에 包含되어 있는 두 parameter q/q1과 a는 吸着熱과 어떤 關聯性이 있는 것으로 推測된다.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.593-599
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• 2003

The nanoparticle magnetite of which diameter was about 3 nm was synthesized in a homogeneous aqueous solution without a template. The synthesized magnetite nanoparticle was easily oxidized to maghemite in an ambient condition. The magnetic properties of the ferrite nanoparticle show superparamagnetism at room temperature and its blocking temperature is around 93 K. Modifying the sequential adsorption method of metal bisphosphonate, we have prepared a multilayer thin film of the ferrite nanoparticle on planar substrates such as glass, quartz and Si wafer. In this multilayer the ferrite nanoparticle layer and an alkylbisphosphonate layer are alternately placed on the substrates by simple immersion in the solutions of the ferrite nanoparticle and 1, 10-decanediylbis (phosphonic acid) (DBPA), alternately. This is the first example, as far as we know, of nanoparticle/alkyl-bisphosphonate multilayer which is an analogy of metal bisphosphonate multilayer. UV-visible absorption and infrared reflection-absorption studies show that the growth of each layer is very systematic and the film is considerably optically transparent to visible light of 400-700 nm. Atomic force microscopic images of the film show that the surface morphology of the film follows that of the substrate in μm-scale image and the nanoparticle-terminated surface is differentiated from the DBPA-terminated one in nm-scale image. The magnetic properties of this ferrite/DBPA thin film are almost the same as those of the ferrite nanoparticle powder only.

• Bulletin of the Korean Chemical Society
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• 제3권2호
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• pp.37-44
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• 1982

In this work we have studied the multilayer stepwise adsorption of gases on solid adsorbents based on the previously developed theory. It is shown that stepwise adsorption isotherms emerge from our theory if an ad hoc adsorption regarding the degree of occupation for each successive layer is abolished and the effect of lateral intermolecular interactions among adsorbate molecules is included. In addition to these the effect of vertical interactions has also been taken into consideration. It seems that the vertical interaction plays a role in deciding the shape and the position of steps in resulting isotherms. It is evident from this research that it is the lateral interaction that is responsible for stepwise adsorption as long as the adsorbent surface is uniform and temperature is sufficiently low.

• Bulletin of the Korean Chemical Society
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• 제2권2호
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• pp.56-59
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• 1981

In this paper a further generalization of the theory of multilayer physical adsorption previously developed by the authors is attempted so that the effect of vertical interactions between adsorbent and adsorbate can be explicitly taken into account. In this attempt we have to discard the previously adopted assumption that the molecules in the second layer or above are all in the same physical state. In order to estimate the effect of vertical interactions on the adsorption isotherm the interaction energy between an adsorbed molecule and the adsorbent surface is assumd to vary as $r^{-3}$ where r is the distance that the molecule under consideration is separated from the adsorbent surface. Resulting adsorption isotherm is applied to interpret the adsorption data of tetramethylsilane vapor on iron film and good agreements between observed and calculated values are obtained over wide range of pressure.

• Bulletin of the Korean Chemical Society
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• 제9권4호
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• pp.244-248
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• 1988

Multilayer adsorption isotherms of nitrogen on hexagonal boron nitride, ${\gamma}$-alumina, and silica-gel powders are determined at the liquid nitrogen temperature using a gravimetric adsorption apparatus. The volume (V) of the adsorbed gas are plotted against the statistical thickness(t) of the adsorbed layer, and the t-method area are calculated from the slope of these V-t plots to compare with the BET area. A number of universal adsorption isotherms and the Frenkel-Halsey-Hill equation are used one after another in calculating the statistical thickness. The appropriateness of the FHH equation as an universal adsorption isotherm is discussed finally.