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Articles 1 - 12 of 12

Full-Text Articles in Physical Chemistry

Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, Sumit Kewalramani, Suntao Wang, Yuan Lin, Huong Giang Nguyen, Qian Wang, Masafumi Fukuto, Lin Yang Nov 2010

Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, Sumit Kewalramani, Suntao Wang, Yuan Lin, Huong Giang Nguyen, Qian Wang, Masafumi Fukuto, Lin Yang

Faculty Publications

We report an experimental demonstration of a strategy for inducing two-dimensional (2D)crystallization of charged nanoparticles on oppositely charged fluid interfaces. This strategy aims to maximize the interfacial adsorption of nanoparticles, and hence their lateral packing density, by utilizing a combination of weakly charged particles and a high surface charge density on the planar interface. In order to test this approach, we investigated the assembly of cowpea mosaic virus (CPMV) on positively charged lipid monolayers at the aqueous solution surface, by means of in situX-ray scattering measurements at the liquid–vapor interface. Theassembly was studied as a function of the solution …


Jahn-Teller Coupling And Fragmentation After Core-Shell Excitation Ini Cf4 Investigated By Partial-Ion-Yield Spectroscopy, Renaud Guillemin, Wayne C. Stolte, Maria Novella Piancastelli, Dennis W. Lindle Oct 2010

Jahn-Teller Coupling And Fragmentation After Core-Shell Excitation Ini Cf4 Investigated By Partial-Ion-Yield Spectroscopy, Renaud Guillemin, Wayne C. Stolte, Maria Novella Piancastelli, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We investigate fragmentation processes induced by core-level photoexcitation in CF4 at both the carbon and fluorine K edges by means of partial-ion-yield spectroscopy. The molecule CF4 is a textbook example of systems in which Jahn-Teller coupling strongly manifests itself in the photoabsorption spectrum. Spectral features related to Jahn-Teller and quasi-Jahn-Teller splitting are observed, and important differences in the fragmentation pathways are revealed depending on the symmetries of the core-excited states. We interpret these experimental observations on the grounds of symmetry lowering from the Td to the C3v point group as well as preferential orientation with respect …


Site-Specific Photocatalytic Splitting Of Methanol On Tio2(110), Chuanyao Zhou, Zefeng Ren, Shijing Tan, Zhibo Ma, Xinchun Mao, Dongxu Dai, Hongjun Fan, Xueming Yang, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Zhou Wang, Zhenyu Li, Bing Wang, Jinlong Yang, Jianguo Hou Sep 2010

Site-Specific Photocatalytic Splitting Of Methanol On Tio2(110), Chuanyao Zhou, Zefeng Ren, Shijing Tan, Zhibo Ma, Xinchun Mao, Dongxu Dai, Hongjun Fan, Xueming Yang, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Zhou Wang, Zhenyu Li, Bing Wang, Jinlong Yang, Jianguo Hou

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Clean hydrogen production is highly desirable for future energy needs, making the understanding of molecular-level phenomena underlying photocatalytic hydrogen production both fundamentally and practically important. Water splitting on pure TiO2 is inefficient, however, adding sacrificial methanol could significantly enhance the photocatalyzed H2 production. Therefore, understanding the photochemistry of methanol on TiO2 at the molecular level could provide important insights to its photocatalytic activity. Here, we report the first clear evidence of photocatalyzed splitting of methanol on TiO2 derived from time-dependent two-photon photoemission (TD-2PPE) results in combination with scanning tunneling microscopy (STM). STM tip induced molecular manipulation …


Energetyka Niskoemisyjna, Wojciech M. Budzianowski Sep 2010

Energetyka Niskoemisyjna, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang Jun 2010

A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A surface femtosecond two-photon photoemission (2PPE) spectrometer devoted to the study of ultrafast excited electron dynamics and photochemical kinetics on metal and metal oxide surfaces has been constructed. Low energy photoelectrons are measured using a hemispheri- cal electron energy analyzer with an imaging detector that allows us to detect the energy and the angular distributions of the photoelectrons simultaneously. A Mach-Zehnder interferom- eter was built for the time-resolved 2PPE (TR-2PPE) measurement to study ultrafast surface excited electron dynamics, which was demonstrated on the Cu(111) surface. A scheme for measuring time-dependent 2PPE (TD-2PPE) spectra has also been developed for studies of …


Grafika Inżynierska Ćw., Wojciech M. Budzianowski Jan 2010

Grafika Inżynierska Ćw., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Projektowanie Procesów Biotechnologicznych Proj., Wojciech M. Budzianowski Jan 2010

Projektowanie Procesów Biotechnologicznych Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Projektowanie I Optymalizacja Procesów Proj., Wojciech M. Budzianowski Jan 2010

Projektowanie I Optymalizacja Procesów Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Metody Numeryczne Lab., Wojciech M. Budzianowski Jan 2010

Metody Numeryczne Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Odnawialne Źródła Energii W., Wojciech M. Budzianowski Jan 2010

Odnawialne Źródła Energii W., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Sulfur K-Edge Photo-Fragmentation Of Ethylene Sulfide, Wayne C. Stolte, Gunnar Ohrwall Jan 2010

Sulfur K-Edge Photo-Fragmentation Of Ethylene Sulfide, Wayne C. Stolte, Gunnar Ohrwall

Chemistry and Biochemistry Faculty Research

We have investigated the photofragmentation properties of the three-membered ring heterocyclic molecule ethylene sulfide or thiirane, C2H4S, by time-of-flight mass spectroscopy. Positive ions have been collected as a function of photon energy around the S K ionization threshold. Branching ratios were derived for all detected ions, which are informative of the decay dynamics and photofragmentation patterns of the core-excited species. We present a new assignment of the spectral features around the S K-edge.


Dynamic Path Bifurcation For The Beckmann Reaction: Observation And Implication, H. Yamataka, M. Sato, H. Hasegawa, Salai Cheettu Ammal Jan 2010

Dynamic Path Bifurcation For The Beckmann Reaction: Observation And Implication, H. Yamataka, M. Sato, H. Hasegawa, Salai Cheettu Ammal

Faculty Publications

The reaction of oximes to amides, known as the Beckmann rearrangement, may undergo fragmentation to form carbocations + nitriles instead of amides when the cations have reasonable stability. The reactions of oxime derivatives of 1-substituted-phenyl-2-propanones and 3-substituted-phenyl-2-butanones in aqueous solvents gave both rearrangement and fragmentation products, the ratio of which was dependent on substituents. Transition state (TS) optimizations and intrinsic reaction coordinate (IRC) calculations for the reaction of 1-phenyl-2-propanone oximes showed that there is a single TS for each substituted compound. The IRC path from the TS either led to a rearrangement product or a fragmentation product depending on the …