• 통합자연과학논문집
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• 제5권3호
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• pp.195-197
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• 2012

Halogen atoms in a molecule are traditionally considered as electron donors, since they have unshared electrons. Normally when they are bonded, there are three lone pair electrons. These lone pairs can function as Lewis bases. However, when they are bound to electron withdrawing groups, they can act as Lewis acids. Since the situation is similar hydrogen bonding (HB), this type of interaction is named as halogen bonding (XB). This mainly comes from the uneven distribution of electron density around the halogen atoms. Since the electron density around halogen atom opposite to ${\sigma}$-bond is depleted, its electropositive region is called ${\sigma}$-hole. This ${\sigma}$-hole can attract halogen bond acceptors, requiring more stringent directionality compared to HB. Since this interaction mainly comes from electrostatic origin, the geometry tends to be linear. Since the XB energy is comparable to corresponding HB. Still in its infancy, XB shows a broad range of applicability, with potentially more useful properties, compared to corresponding HB.

• Restorative Dentistry and Endodontics
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• 제29권6호
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• pp.504-514
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• 2004

LED 광중합기(Elipar FreeLight, 3M-ESPE)와 할로겐 광중합기(VIP Bisco)로 광조사한 수종의 상아질 접착제에 대해서 상아질 전단접착강도를 비교하였다 또한 이번 연구의 광학적 근거를 얻기 위해 두 광중합기의 파장에 따른 광강도와 스펙트럼을 비교하였다. 이번 연구에서 사용된 상아질 접착제는 Scotchbond Multipurpose (3M ESPE), Single Bond (3M ESPE). One-Step (Bisco), Clearfil SE Bond (Kuraray), Adper Prompt (3M ESPE) 이다. VIP는 487 nm에서 최대정점을 가지는 넓은 스펙트럼의 분포를 보이는 반면에, Elipar FreeLight는 465 nm에서의 최대정점을 중심으로 좁은 스펙트럼의 분포를 보였다. Clearfil SE bond를 제외하고 할로겐과 LED로 광조사 한 각 상아질 접착제에서 상아질 전단접착강도값의 유의성 있는 차이는 보이지 않았다 (P > 0.05). 이러한 결과는 camphoroquinone의 흡수스펙트럼과 LED의 좁은 영역의 스펙트럼사이에 강한 연관성으로 설명할 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.11-11
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• 2010

Supramolecualr ordering has been actively studied due to it's possible applications to the fabrication processes of nano-electronic devices. Van der Waals interaction and hydrogen bonding are frequently studied mechanisms for various molecular structures based on non-uniform charge distributions. Halogen atoms in molecules can have electrostatic interactions with similar strength. Big halogen atoms have strong non-uniform charge distributions. To study molecular orderings formed by hydrogen and halogen interactions, we chose a molecular system containing oxygen, hydrogen, and bromine atoms, a bromo-quinone. A two-dimensional molecular network was studied on Au(111) using a low-temperature scanning tunneling microscope. Bromo-quinonemolecules form self-assembled square grids having windmill structures. Their molecular orderings, chiral structures, and defects are explained in terms of hydrogen and halogen interactions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.354-354
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• 2010

Supramolecualr ordering has been actively studied due to it's possible applications to the fabrication processes of nano-electronic devices. Van der Waals interaction and hydrogen bonding are frequently studied mechanisms for various molecular structures based on non-uniform charge distributions. Halogen atoms in molecules can have electrostatic interactions with similar strength. Big halogen atoms have strong non-uniform charge distributions. To study molecular orderings formed by hydrogen and halogen interactions, we chose a molecular system containing oxygen, hydrogen, and bromine atoms, a bromo-quinone. A two-dimensional molecular network was studied on Au(111) using a low-temperature scanning tunneling microscope. Bromo-quinone molecules form self-assembled square grids having windmill structures. Their molecular orderings, chiral structures, and defects are explained in terms of hydrogen and halogen interactions.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.576-577
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• 2003

I. Objectives This study investigated the dentin shear bond strength and the degree of conversion (DC) of currently used dentin bonding agents (DBAs) that were irradiated with a light emitting diode (LED) light curing unit (LCU) and a halogen LCU. II. Materials and methods The halogen LCU and the LED LCU used in this study were a VIP(Bisco, Schaumburg, IL, USA) and an Elipar Freelight(3M ESPE, St Paul, MN, USA) respectively. For the VIP, $400mW{\cdot}cm-2$ intensity mode was used to adjust to the intensity of the LED LCU. The DBAs used in this study were Scotchbond Multipurpose (3M ESPE), Single Bond (3M ESPE), One-step(Bisco), Clearfil SE Bond(Kuraray), and Adper Prompt(3M ESPE).(omitted)

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.443-447
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• 1989

The mechanism on the oxidative addition reaction of $(TBA)_2\;Pt(CN)_4$ with $Cl_2$ has been studied by means of extended Huckel calculations. Among two possible mechanisms, computational calculations demonstrated that the linear approach of $Cl_2$ to a $Pt(CN)_4$ moiety is more favourable than three-centered transition state. From our calculations, the most stable process is that a $Pt(CN)_4$ moiety interacts with $Cl_2$ in the linear transition state and the cleavage of Cl-Cl bond in a coordinated halogen occurred spontaneously, giving rise to a trans product by back-attacking a $Pt(CN)_4Cl$ moiety by Cl. The process consists of the comparison in the stability of each intermediate with use of bonding and potential energy.

• 한국환경과학회지
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• 제6권1호
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• pp.75-88
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• 1997

The rates of photodegradation, reactivities, and mechanisms of photooxidation for the aqueous solution containing with halogen derivatives of aliphatic hydrocarbons have been discussed with respect to the kinds of photocatalysts, concentration of photocatalytlc suspensions, strength of radiant power, time of illumination, changes of pH of substrate solution, wavelength of radiation, and pressure of oxygen gas saturated In the solution. These aqueous solutions suspended with 0.5 $gL^{-1}$ $TiO_2$ powder have been photodecomposed in the range of 100 and 93.8% per 1 hour if it is illuminated with wavelength (λ $\geq$ 300nm) produced from Xe-lamp(450W). The photocatalytic abilities have been increased In the order of $Fe_2O_3$ < CdS < $CeO_2$ < Y_2O_3$ <$TiO_2$, and rates of photodegradation for the solution have maldmum values in the condition of pH 6 ~ 8 and 3 psi-$O_2$ gL^{-1}$. These rates for the Photoolddation Per 1 hour were dependent on the size of molecular weight and chemical bonding for organic halogen compounds and the rates of photodegadation were increased in the order of $C_2H_5Br$ < CH_2Br_2$ < C_5H_11Cl C_2H_4Cl_2$ < tracts-$C_2H_2Cl_2$ < cis-C_2H_2Cl_2$ The T_{1/2}$ and t99% for these solutions were 5~21 and 40~90 minutes. respectively, and these values were coincided with Initial reaction kinetics(ro). It was found that reaction of photodegradation has the pseudo first-order kinetics controlled by the amount of $h^+_{VB}$ diffused from a surface of photocatalysts.

• 한국재료학회지
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• 제14권5호
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• pp.315-321
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• 2004

The void evolution in direct bonding process of $Si/Si_3$$N_4$ ∥ $SiO_2$/Si silicon wafer pairs has been investigated with an infrared camera. The voids that formed in the premating process grew in the conventional furnace annealing process at a temperature of $600^{\circ}C$. The voids are never shrunken even with the additional annealing process at the higher temperatures. We observed that the voids became smaller and disappeared with sequential scanning by our newly proposed fast linear annealing(FLA). FLA irradiates the focused line-shape halogen light on the surface while wafer moves from one edge to the other. We also propose the void shrinking mechanism in FLA with the finite differential method (FDM). Our results imply that we may eliminate the voids and enhance the yield for the direct bonding of wafer pairs by employing FLA.

• 한국전기전자재료학회논문지
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• 제15권4호
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• pp.301-307
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• 2002

Direct bonded SOI wafer pairs with $Si ll SiO_2/Si_3N_4 ll Si$ the heterogeneous insulating layers of SiO$_2$-Si$_3$N$_4$are able to apply to the micropumps and MEMS applications. Direct bonding should be executed at low temperature to avoid the warpage of the wafer pairs and inter-diffusion of materials at the interface. 10 cm diameter 2000 ${\AA}-SiO_2/Si(100}$ and 560 $\AA$- ${\AA}-Si_3N_4/Si(100}$ wafers were prepared, and wet cleaned to activate the surface as hydrophilic and hydrophobic states, respectively. Cleaned wafers were pre- mated with facing the mirror planes by a specially designed aligner in class-100 clean room immediately. We employed a heat treatment equipment so called fast linear annealing(FLA) with a halogen lamp to enhance the bonding of pre mated wafers We kept the scan velocity of 0.08 mm/sec, which implied bonding process time of 125 sec/wafer pairs, by varying the heat input at the range of 320~550 W. We measured the bonding area by using the infrared camera and the bonding strength by the razor blade clack opening method, respective1y. It was confirmed that the bonding area was between 80% and to 95% as FLA heat input increased. The bonding strength became the equal of $1000^{\circ}C$ heat treated $Si ll SiO_2/Si_3N_4 ll Si$ pair by an electric furnace. Bonding strength increased to 2500 mJ/$\textrm{m}^2$as heat input increased, which is identical value of annealing at $1000^{\circ}C$-2 hr with an electric furnace. Our results implies that we obtained the enough bonding strength using the FLA, in less process time of 125 seconds and at lowed annealing temperature of $400^{\circ}C$, comparing with the conventional electric furnace annealing.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2008년도 Spring Scientific Meeting(the 129th) of Korean Academy if Conservative Dentistry
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• pp.213-223
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• 2008

광물리학적 특성 분석을 위해 Apollo 95E (DMT Systems, Orange, CA : PAC 광중합기), Elipar Freelight 2 (3M ESPE, MN, USA; LED 광중합기) 그리고 VIP Junior (Bisco, Schaumberg, IL, USA : QTH 광중합기), 3종의 광중합기의 총광강도(Total intensity)와 spectral distribution을 측정하였고 특정 파장에 해당되는 광강도(Energy density)를 분석하였다. 상아질 전단접착강도의 측정을 위해 Scotchbond Multipurpose (3M ESPE), Single bond (3M ESPE) 그리고 Clearfil SE bond (Kuraray)가 사용되었다. Plasma Arc Curing light (Apollo 95E) 광중합기는 여러개의 최대정점을 가지며 넓은 spectral distribution과 $2307mW/cm^2$의 높은 광강도를 나타내었고, VIP Junior 광중합기는 490 nm에서 최대정점을 갖는 넓은 spectral distribution을 나타내었고, Elipar Freeelight 2 광중합기는 462 nm의 최대정점 주위로 좁은 spectral distribution을 보였다. Two-Way ANOVA와 Bonferroni's multiple comparison test를 이용하여 상아질 전단접착강도를 분석한 결과, PAC 광중합기와 LED 광중합기 간에 유의성 있는 차이를 보이지 않았으며 (P > 0.05), 상아질 접착제와 광중합기의 교호관계에도 유의성이 없었다. 그러나 상아질 접착제는 상호간에 유의성 있는 차이를 보였다 (P < 0.00).