Funding from the European Research Council (ERC Grant 239831) and a Humboldt Fellowship (BS) is gratefully acknowledged.

The authors have nothing to disclose.

원하는 hexayne의 친 양쪽 성체 (3) 노골적 순차 브롬화 (52, 53)에 의해 제조되고 tritylphenyl 에스테르 (2) (도 1a) (29)의 최종적인 탈 보호 반응에 의해, 알킨 세그먼트의 신도 (30, 31)을 팔라듐이 촉매 작용 하였다. 성공적인 합성 31,54 13 C NMR 스펙트럼 (도 1b)에서뿐만 아니라 UV-비스 흡수 스펙트럼 (도 1C)를 확인한다. 이것은 높...

이차원 탄소 나노 인해보고 우수한 열적, 전기적뿐만 아니라 기계적 성질 1-5에 상당한 관심을 끈다. 이들 물질은 폴리머 복합체 6, 에너지 저장 장치 (7) 및 전자 분자 8-10의 분야에서 기술적 인 발전을 촉진 할 것으로 예상된다. 최근 몇 년 동안 집중적 인 연구 노력에도 불구하고, 잘 정의 된 탄소 나노 재료의 많은 양에 대한 액세스는 여전히 기술적 애플리케이션 (11, 12)에서의 대형 구현을 방해하는 제한된다. 탄소 나노 물질 중 하나 하향식 또는 상향식 (bottom-up) 접근 방식으로 액세스 할 수 있습니다. 이러한면 14-16에서 박리 기술 (13) 또는 고 에너지 처리와 일반적인 접근법 구조적 완전성 매우 좋은 성능의 높은 수준의 재료를 얻을 수있는 가능성을 제공한다. 그러나, 단리 및 정제 번째전자 제품은 도전 남아 있고 정의 나노 물질의 대량 생산이 곤란하다 (12). 한편, 상향식 접근은 분자 전구체의 사용에 의존하는 정의 된 구조로 구성하고, 카본 나노 구조물을 산출 17-23 후속의 탄화를 사용할 수있다. 이 경우, 전구체 자체는 더 복잡하고 이들의 제조는 종종 다수의 합성 단계를 필요로한다. 이러한 접근법 얻어진 재료의 화학적 및 물리적 특성을 고도의 제어를 제공 할 수 있고, 맞춤형 재료에 직접 액세스를 제출된다. 그러나, 탄소 나노 물질에 전구체의 변환은 일반적으로 포함 화학 작용 24-27의 손실에 이르게 800 ° C,보다 높은 온도에서 수행된다. 위에서 언급 한 제한은 캘리포니아 반응성이 매우 높은 oligoynes을 이용하여 우리 그룹에서 해결되었습니다n은 실온 (28, 29)에 탄소 나노 물질로 변환 될 수있다. 특히, 친수성 헤드 기 및 hexayne 세그먼트를 포함하는 양친은 브롬화 팔라듐 - 매개 네기 교차 - 커플 링 반응 (30, 31)의 시퀀스를 통해 접근 가능하다. 타겟 구조로 이들 전구체 분자의 변환이나 UV 광 조사에 의해 상온 이하로 발생한다. oligoyne의 양친의 높은 반응성은 가능한 공기 - 물 계면 또는 유체 - 유체 인터페이스, 소프트 템플릿을 사용할 수있다. 이전 연구에서, 우리는 성공적으로 hexayne 글리코 시드의 양친 (28)의 솔루션에서 소포를 준비했다. 이러한 소체의 가교는 샘플의 UV 조사에 의해 온화한 조건 하에서 이루어졌다. 또한, 최근 카르 복실 산 메틸 머리 기 및 랭 뮤어 통 내의 공기 - 물 계면에서 소수성 알킬 꼬리 hexaynes으로부터 자기 조직화 단층을 준비했다. 조밀 팩에드 분자 전구체는 노골적 UV 조사에 의해 상온에서 자립 탄소 나노 시트로 전환 하였다. 종래 방식에서 정의 된 분자 전구체는 최근 공기 - 물 계면에서 32-38 이차원 적으로 전개 된 나노 시트의 제조에 사용되어왔다. 이 연구의 목적은 hexayne의 양친으로부터 탄소 나노 시트의 제조를 허용 전반적인 합성 및 제조 공정 간결 실질적인 개요를 제공하는 것이다. 초점은 실험적인 접근 방법과 예비 질문입니다.

<table border="0" cellpadding="0" cellspacing="0" width="1557">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Methyllithium lithium bromide complex (2.2M solution in diethylether)</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">18129-1000</td>
			<td style="width:731px;">air-sensitive, flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Zinc chloride (0.7M solution in THF)</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">38945-1000</td>
			<td>air-sensitive, flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">1,1&#39;-Bis(diphenylphosphino)ferrocene] 
			dichloropalladium(II), DCM adduct&#160;</td>
			<td style="width:195px;">Boron Molecular</td>
			<td style="width:119px;">BM187</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">N-Bromosuccinimide</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">10745</td>
			<td>light-sensitive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Silver fluoride</td>
			<td style="width:195px;">Fluorochem</td>
			<td style="width:119px;">002862-10g</td>
			<td>light-sensitive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">n-Butyllithium (2.5M solution in hexanes)</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">21335-1000</td>
			<td>air-sensitive, flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Sodium methanolate</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">17312-0050</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Tetrahydrofuran (unstabilized, for HPLC)</td>
			<td style="width:195px;">Fisher Chemicals</td>
			<td style="width:119px;">T/0706/PB17</td>
			<td>This solvent was dried as well as degassed using a solvent purification system (Innovative Technology, Inc, Amesbury, MA, USA)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Toluene (for HPLC)</td>
			<td style="width:195px;">Fisher Chemicals</td>
			<td style="width:119px;">T/2306/17</td>
			<td>This solvent was dried as well as degassed using a solvent purification system (Innovative Technology, Inc, Amesbury, MA, USA)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Acetonitrile (for HPLC)</td>
			<td style="width:195px;">Fisher Chemicals</td>
			<td style="width:119px;">A/0627/17</td>
			<td>This solvent was dried as well as degassed using a solvent purification system (Innovative Technology, Inc, Amesbury, MA, USA)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Dichloromethane (Extra Dry over Molecular Sieve)</td>
			<td style="width:195px;">Acros</td>
			<td style="width:119px;">34846-0010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Chloroforme (p.a.)</td>
			<td style="width:195px;">VWR International</td>
			<td style="width:119px;">1.02445.1000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Pentane</td>
			<td style="width:195px;">Reactolab</td>
			<td style="width:119px;">99050</td>
			<td>Purchased as reagent grade and distilled once prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Heptane</td>
			<td style="width:195px;">Reactolab</td>
			<td style="width:119px;">99733</td>
			<td>Purchased as reagent grade and distilled once prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Dichloromethane</td>
			<td style="width:195px;">Reactolab</td>
			<td style="width:119px;">99375</td>
			<td>Purchased as reagent grade and distilled once prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Diethylether</td>
			<td style="width:195px;">Reactolab</td>
			<td style="width:119px;">99362</td>
			<td>Purchased as reagent grade and distilled once prior to use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Geduran silica gel (Si 60, 40-60&#181;m)</td>
			<td style="width:195px;">Merck</td>
			<td style="width:119px;">1115671000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Langmuir trough</td>
			<td style="width:195px;">R&#38;K, Potsdam</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thermostat&#160;</td>
			<td style="width:195px;">E1 Medingen</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hamilton syringe&#160;</td>
			<td>Model 1810 RN SYR</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Vertex 70 FT-IR spectrometer&#160;</td>
			<td style="width:195px;">Bruker</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">External air/water reflection unit (XA-511)&#160;</td>
			<td style="width:195px;">Bruker</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">UV lamp (250 W, Ga-doped metal halide bulb)</td>
			<td style="width:195px;">UV-Light Technology</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Brewster angle microscope (BAM1+)&#160;</td>
			<td style="width:195px;">NFT G&#246;ttingen</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Sapphire substrates</td>
			<td style="width:195px;">Stecher Ceramics</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:513px;">Quantifoil holey carbon TEM grids</td>
			<td style="width:195px;">Electron Microscopy Sciences</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Nuclear magnetic resonance spectrometer (Bruker Avance III 400)</td>
			<td style="width:195px;">Bruker</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">JASCO V-670 UV/Vis spectrometer</td>
			<td style="width:195px;">JASCO</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:513px;">Scanning Electron Microscope (Zeiss Merlin FE-SEM)</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation of carbon nanosheets at room temperature

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into defined aggregates in aqueous media and at the air-water interface. In the aggregated state, the oligoynes can then be carbonized under mild conditions while preserving the morphology and the embedded chemical functionalization. This novel approach provides direct access to functionalized carbon nanomaterials. In this article, we present a synthetic approach that allows us to prepare hexayne carboxylate amphiphiles as carbon-rich siblings of typical fatty acid esters through a series of repeated bromination and Negishi-type cross-coupling reactions. The obtained compounds are designed to self-assemble into monolayers at the air-water interface, and we show how this can be achieved in a Langmuir trough. Thus, compression of the molecules at the air-water interface triggers the film formation and leads to a densely packed layer of the molecules. The complete carbonization of the films at the air-water interface is then accomplished by cross-linking of the hexayne layer at room temperature, using UV irradiation as a mild external stimulus. The changes in the layer during this process can be monitored with the help of infrared reflection-absorption spectroscopy and Brewster angle microscopy. Moreover, a transfer of the carbonized films onto solid substrates by the Langmuir-Blodgett technique has enabled us to prove that they were carbon nanosheets with lateral dimensions on the order of centimeters.

준비된 전구체 분자의 C 13 핵 자기 공명 (NMR) 스펙트럼 (3) 디스플레이 δ = 82-60 PPM (도 1B)에 대응하는 화학 시프트와 hexayne 세그먼트의 12 SP -hybridized 탄소수. 또한, δ = 173 ppm에서와 δ = 52 ppm에서 신호가 각각 에스테르의 카르 보닐 메틸 탄소에 할당됩니다. δ = 33-14 PPM 간의 신호 도데 실 잔기의 지방족 탄소에 기인한다. (3)의</stro...

Watch this Scientific Journal Video about Preparation of Carbon Nanosheets at Room Temperature at JoVE.com

Preparation of Carbon Nanosheets at Room Temperature

We present the synthesis of an amphiphilic hexayne and its use in the preparation of carbon nanosheets at the air-water interface from a self-assembled monolayer of these reactive, carbon-rich molecular precursors.

실내 온도에서 탄소 나노 시트의 제조

Amphiphilic molecules equipped with a reactive, carbon-rich "oligoyne" segment consisting of conjugated carbon-carbon triple bonds self-assemble into ...

preparation-of-carbon-nanosheets-at-room-temperature

Research

Education

JoVE Journal

JoVE Core

Chemistry

Chemical Bonding: Basic Concepts

SCIENTISTS IN ACTION

12.0K 조회수.  Ecole Polytechnique Fédérale de Lausanne (EPFL). We present the synthesis of an amphiphilic hexayne and its use in the preparation of carbon nanosheets at the air-water interface from a self-assembled monolayer of these reactive, carbon-rich molecular precursors.

비디오: Preparation of Carbon Nanosheets at Room Temperature

Transport of Surface-modified Carbon Nanotubes through a Soil Column

Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, electronics and biomedical applications. Due to their accelerating production and use, CNTs constitute a potential environmental risk if they are released to soil and groundwater systems. It is therefore essential to improve the current understanding of environmental fate and transport of CNTs. The transport and retention of CNTs in both natural and artificial media have been reported in literature, but the findings widely vary and are thus not conclusive. There are a number of physical and chemical parameters responsible for variation in retention and transport. In this study, a complete procedure of selected multiwalled carbon nanotubes (MWCNTs) is presented starting from their surface modification to a complete set of laboratory column experiments at critical physical and chemical scenarios. Results indicate that the stability of the commercially available MWCNTs are critical with their attached surface functional group which can also influence the transport and retention of MWCNT through the surrounding medium.

Surface properties of a nanoparticle are important for their interaction with the surrounding medium. Therefore the surface modification of carbon nanotubes can be critical for their transport and retention through porous media. Here, lab scale column experiments are used to understand the possible transport and retention of these nanoparticles.

토양 칼럼을 통해 표면 개질 된 카본 나노 튜브의 운송

Carbon nanotubes (CNTs) are widely manufactured nanoparticles, which are being utilized in a number of consumer products, such as sporting goods, ...

연구

화학

Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions

Estimates of the primitive upper mantle (PUM) composition reveal a depletion in many of the siderophile (iron-loving) elements, thought to result from their extraction to the core during terrestrial accretion. Experiments to investigate the partitioning of these elements between metal and silicate melts suggest that the PUM composition is best matched if metal-silicate equilibrium occurred at high pressures and temperatures, in a deep magma ocean environment. The behavior of the most highly siderophile elements (HSEs) during this process however, has remained enigmatic. Silicate run-products from HSE solubility experiments are commonly contaminated by dispersed metal inclusions that hinder the measurement of element concentrations in the melt. The resulting uncertainty over the true solubility and metal-silicate partitioning of these elements has made it difficult to predict their expected depletion in PUM. Recently, several studies have employed changes to the experimental design used for high pressure and temperature solubility experiments in order to suppress the formation of metal inclusions. The addition of Au (Re, Os, Ir, Ru experiments) or elemental Si (Pt experiments) to the sample acts to alter either the geometry or rate of sample reduction respectively, in order to avoid transient metal oversaturation of the silicate melt. This contribution outlines procedures for using the piston-cylinder and multi-anvil apparatus to conduct solubility and metal-silicate partitioning experiments respectively. A protocol is also described for the synthesis of uncontaminated run-products from HSE solubility experiments in which the oxygen fugacity is similar to that during terrestrial core-formation. Time-resolved LA-ICP-MS spectra are presented as evidence for the absence of metal-inclusions in run-products from earlier studies, and also confirm that the technique may be extended to investigate Ru. Examples are also given of how these data may be applied.

We present a procedure to determine the metal-silicate partitioning of siderophile elements, emphasizing techniques that suppress the formation of metal inclusions in experiments for the noble metals. The results of these experiments are used to demonstrate the effect of core-formation on the highly siderophile element composition of the mantle.

실험 방법 및 높은 Siderophile 요소 흠을 억제하는 프로토콜 : 높은 압력과 온도에서 금속 규산염 분할

Estimates of the primitive upper mantle (PUM) composition reveal a depletion in many of the siderophile (iron-loving) elements, thought to result from ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

탄소 나노 튜브에 의해 안정화 내부 자기 조립 된 지질 입자의 용이 한 제조

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. Detailed and generalized protocols are also presented for testing the catalytic activity of such complexes in arylation and Suzuki-Miyaura cross-coupling reactions. Representative results are shown for the catalytic activity of the four complexes in arylation and Suzuki-Miyaura type reactions. For each of the reactions investigated, at least one of the four complexes successfully catalyzed the reaction, qualifying them as promising candidates for catalysis of many carbon-carbon bond-forming reactions. The protocols presented are general enough to be adapted for the synthesis, purification and catalytic activity testing of new palladium N-heterocyclic carbene complexes.

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. The complexes were tested for catalytic activity in arylation and Suzuki-Miyaura reactions. For each reaction investigated, at least one of the four complexes successfully catalyzed the reaction.

보장<em&gt; N</em&gt; - 헤테로 사이 클릭 카벤 착물 : 벤즈 이미 다 졸리움 염으로부터의 합성 및 탄소 - 탄소 결합 형성 반응에서의 촉매 활성

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). In the case of fast reversible electrochemical processes, current is predominantly affected by the rate of diffusion, which is the slowest and limiting stage. EIS is a powerful technique that allows separate analysis of stages of charge transfer that have different AC frequency response. The capability of the method was used to extract the value of charge transfer resistance, which characterizes the rate of charge exchange on the electrode-solution interface. The application of this technique is broad, from biochemistry up to organic electronics. In this work, we are presenting the method of analysis of organic compounds for optoelectronic applications.

Electrochemical impedance spectroscopy (EIS) of species that undergo reversible oxidation or reduction in solution was used for determination of rate constants of oxidation or reduction.

전기 화학 임피던스 분 광 전기 화학 속도 상수 추정을 위한 도구로

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables the acquisition of photoluminescence spectra covering the time regime from nanoseconds up to 0.1 s. This enables us to follow the changes in the intensity (decay) and emission of the spectra over time. Using this method, it is possible to study diverse photophysical phenomena, such as the emission of phosphorescence, and the contributions of prompt and delayed fluorescence in molecules showing thermally activated delayed fluorescence (TADF). Remarkably, all spectra and decays are obtained in a single experiment. This can be done for solids (thin film, powder, crystal) and liquid samples, where the only limitations are the spectral sensitivity of the camera and the excitation wavelength (532 nm, 355 nm, 337 nm, and 266 nm). This technique is, thus, very important when investigating the excited state dynamics in organic emitters for their application in organic light-emitting diodes and other areas where triplet harvesting is of paramount importance. Since triplet states are strongly quenched by oxygen, emitters with efficient TADF luminescence, or those showing room temperature phosphorescence (RTP), must be correctly prepared in order to remove any dissolved oxygen from solutions and films. Otherwise, no long-lived emission will be observed. The method of degassing solid samples as presented in this work is basic and simple, but the degassing of liquid samples creates additional difficulties and is particularly interesting. A method of minimizing solvent loss and changing the sample concentration, while still enabling to remove oxygen in a very efficient and a repeatable manner, is presented in this work.

Here, we present a method of the spectroscopic characterization of organic molecules by means of time-resolved photoluminescence spectroscopy on the nanosecond-to-millisecond timescale in oxygen-free conditions. Methods to efficiently remove oxygen from the samples and, thus, limit luminescence quenching are also described.

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables ...

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule on the vibrational level of energy. Raman and IR spectroelectrochemistry can be used for advanced characterization of the structural changes in the organic electroactive compounds. Here, the step-by-step analysis by means of Raman and IR spectroelectrochemistry is shown. Raman and IR spectroelectrochemical techniques provide complementary information about structural changes occurring during an electrochemical process, i.e. allows for the investigation of redox processes and their products. The examples of IR and Raman spectroelectrochemical analysis are presented, in which the products of the redox reactions, both in solution and solid state, are identified.

A protocol of step-by-step Raman and IR spectroelectrochemical analysis is presented.

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule ...

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance (EPR) or ultraviolet-visible and near-infrared (UV-Vis-NIR) spectroscopies, we obtain useful information such as electron affinity, ionization potential, band-gap energies, the type of charge carriers, and degradation information that can be used to synthesize stable organic electronic devices. In this study, we present electrochemical and spectroelectrochemical methods to analyze the processes occurring in active layers of an organic device as well as the generated charge carriers.

In this article, we describe electrochemical, electron paramagnetic resonance, and ultraviolet-visible and near-infrared spectroelectrochemical methods to analyze organic compounds for application in organic electronics.

사용 하 여 순환 Voltammetry, UV-Vi-NIR, EPR Spectroelectrochemistry 유기 화합물 분석

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance ...

Surface Properties of Synthesized Nanoporous Carbon and Silica Matrices

In this work, we report the synthesis and characterization of ordered nanoporous carbon material (also called ordered mesoporous carbon material [OMC]) with a 4.6 nm pore size, and ordered silica porous matrix, SBA-15, with a 5.3 nm pore size. This work describes the surface properties of nanoporous molecular sieves, their wettability, and the melting behavior of D2O confined in the differently ordered porous materials with similar pore sizes. For this purpose, OMC and SBA-15 with highly ordered nanoporous structures are synthesized via impregnation of the silica matrix by applying a carbon precursor and by the sol-gel method, respectively. The porous structure of investigated systems is characterized by an N2 adsorption-desorption analysis at 77 K. To determine the electrochemical character of the surface of synthesized materials, potentiometric titration measurements are conducted; the obtained results for OMC shows a significant pHpzc shift toward the higher values of pH, relative to SBA-15. This suggests that investigated OMC has surface properties related to oxygen-based functional groups. To describe the surface properties of the materials, the contact angles of liquids penetrating the studied porous beds are also determined. The capillary rise method has confirmed the increased wettability of the silica walls relative to the carbon walls and an influence of the pore roughness on the fluid/wall interactions, which is much more pronounced for silica than for carbon mesopores. We have also studied the melting behavior of D2O confined in OMC and SBA-15 by applying the dielectric method. The results show that the depression of the melting temperature of D2O in the pores of OMC is about 15 K higher relative to the depression of the melting temperature in SBA-15 pores with a comparable 5 nm size. This is caused by the influence of adsorbate/adsorbent interactions of the studied matrices.

Here we report the synthesis and characterization of ordered nanoporous carbon (with a 4.6 nm pore size) and SBA-15 (with a 5.3 nm pore size). The work describes the surface and textural properties of nanoporous molecular sieves, their wettability, and the melting behavior of D2O confined in the materials.

합성된 성공 탄소 그리고 실리 카 매트릭스의 표면 특성

In this work, we report the synthesis and characterization of ordered nanoporous carbon material (also called ordered mesoporous carbon material [OMC]) ...

Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid

The accurate molecular simulation prediction of vibrational spectra, and other structural, energetic and spectral characteristics, of photo-active metal-oxide surfaces in contact with light-absorbing dyes is an ongoing thorny and elusive challenge in physical chemistry. With this in mind, a molecular-dynamics (MD) simulation were performed by using optimized empirical potentials for a well-representative and prototypical dye-sensitized solar cell (DSC) solvated by a widely-studied room temperature ionic liquid (RTIL), in the guise of a [bmim]+[NTf2]- RTIL solvating an N719-sensitizing dye adsorbed onto 101 anatase-titania. In doing so, important insights were gleaned into how using a RTIL as the electrolytic hole acceptor modulates the dynamical and vibrational properties of a N719 dye, estimating the spectra for the DSC photo-active interface via Fourier transformation of mass-weighted velocity autocorrelation functions from MD. The acquired vibrational spectra were compared with the experiment spectra and those sampled from ab initio molecular dynamics (AIMD); in particular, various empirical-potential spectra generated from MD provide insight into how partial-charge charge parameterization of the ionic liquid affects vibrational spectra prediction. In any event, careful fitting of empirical force-field models has been shown to be an effective tool in handling DSC vibrational properties, when validated by AIMD and an experiment.

A dye-sensitized solar cell was solvated by RTILs; using optimized empirical potentials, a molecular dynamics simulation was applied to compute vibrational properties. The obtained vibrational spectra were compared with experiment and ab initio molecular dynamics; various empirical potential spectra show how partial-charge charge parameterization of the ionic liquid affects vibrational spectra prediction.

실내 온도에서 탄소 나노 시트의 제조

요약

더 많은 비디오 탐색

PLAYLIST