Article
Chemistry, Multidisciplinary
Emilie S. Vosegaard, Maja K. Thomsen, Lennard Krause, Thomas B. E. Gronbech, Aref Mamakhel, Seiya Takahashi, Eiji Nishibori, Bo B. Iversen
Summary: Melamine is a precursor for graphitic carbon nitride (g-CN) materials, which have great potential for catalytic applications. The crystal structure of melamine reveals wave-like planes with interlayer distances similar to g-CN. The study shows that hydrogen bonding and π-interactions dominate both intra- and interlayer structures. The unique amine group in melamine may play a crucial role in the condensation process of g-CN.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Takashi Takeda, Kousuke Kato, Hajime Kiyono, Naoto Hirosaki
Summary: In this study, single phase powders of green emitting Ba2LiSi7-xAlxN12-xOx:Eu2+ phosphor were successfully prepared by controlling starting compositions, annealing conditions, and reaction vessels. The emission peak shifted depending on the Eu concentration, with the highest intensity observed at 3 at%. The phosphor exhibited a small thermal quenching of luminescence intensity and showed a high internal quantum efficiency of 93% when washed with hydrochloric acid solution.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Applied
Matthieu Moret, Adrien Rousseau, Pierre Valvin, Sachin Sharma, Laurent Souqui, Henrik Pedersen, Hans Hogberg, Guillaume Cassabois, Jianhan Li, J. H. Edgar, Bernard Gil
Summary: Boron nitride (BN) layers with sp(2) bonding were grown by metal organic chemical vapor deposition on AlN underlayers, showing ordered rhombohedral (rBN) and partially ordered turbostratic (tBN) structures. The optical signature of tBN at 5.45eV appears between the two recombination bands typical of rBN at 5.35eV (strong intensity) and 5.55eV (weaker intensity), distinguishing from the hBN and bBN.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Chi Li, Yi-Xiu Chen, Jagabandhu Patra, Shi-Xian Lu, Chien-Te Hsieh, Chun-Chen Yang, Quan-Feng Dong, Ju Li, Jeng-Kuei Chang
Summary: This work investigates the self-discharge properties of two commonly-used positive electrode materials for rechargeable aluminum batteries (RABs), natural graphite (NG) and expanded graphite (EG). It is found that EG exhibits a higher self-discharge rate compared to NG. The self-discharge loss is attributed to the deintercalation of AlCl4- anions from the graphite lattice, which can be restored in the next charge-discharge cycle.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Multidisciplinary Sciences
Dongju Lee, Seo Gyun Kim, Seungki Hong, Cristina Madrona, Yuna Oh, Min Park, Natsumi Komatsu, Lauren W. Taylor, Bongjin Chung, Jungwon Kim, Jun Yeon Hwang, Jaesang Yu, Dong Su Lee, Hyeon Su Jeong, Nam Ho You, Nam Dong Kim, Dae-Yoon Kim, Heon Sang Lee, Kun-Hong Lee, Junichiro Kono, Geoff Wehmeyer, Matteo Pasquali, Juan J. Vilatela, Seongwoo Ryu, Bon-Cheol Ku
Summary: Multidimensional nanostructures formed by coalescence of carbon nanotubes can create fibers with exceptional mechanical and electrical properties.
Article
Chemistry, Multidisciplinary
Benjamin T. Diroll, Alexandra Brumberg, Ariel A. Leonard, Shobhana Panuganti, Nicolas E. Watkins, Shelby A. Cuthriell, Samantha M. Harvey, Eli D. Kinigstein, Jin Yu, Xiaoyi Zhang, Mercouri G. Kanatzidis, Michael R. Wasielewski, Lin X. Chen, Richard D. Schaller
Summary: In this study, the photothermal response of titanium nitride nanoparticles was investigated using transient X-ray diffraction, revealing dynamic changes in lattice temperature under different excitation intensities. It was found that increasing excitation intensity leads to slower increases in lattice temperature, indicating higher heat capacity at higher powers. Additionally, higher excitation intensity was also found to result in unexpectedly slower cooling of the nanoparticles, attributed to heating of the solvent near the nanoparticle surface.
Article
Engineering, Environmental
Tim Platte, Nicolas Finck, Frank Heberling, Robert Polly, Tim Pruessmann, Kathy Dardenne, Horst Geckeis
Summary: Research shows that green rust chloride (GR-Cl) can retain iodide at low ionic strengths and pH levels between 7.5 and 8.5. The sorption of iodide by GR-Cl is influenced by ion exchange and the transformation of GR-Cl/I phases to magnetite. The presence of sulfate anions inhibits the uptake of iodide.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Ki-Hong Kim, Won-Beom Lee, Tae-Hwan Kim, Seok-Won Son
Summary: Potential-controlled nitriding is an effective technique for improving the surface hardness and toughness of steel molds and dies. This study investigated the effect of nitriding potential on the microstructure and fracture toughness of nitrided AISI D2 steels. It was found that as the nitriding potential increased, the compound layer grew, resulting in an increase in surface hardness and fracture toughness. However, at higher nitriding potential, the presence of increased porosity in the compound layers led to a decrease in both surface hardness and fracture toughness. Additionally, the fracture toughness was influenced by the location of initial cracks and the characteristics of the diffusion and compound layers.
Article
Chemistry, Multidisciplinary
Shuo Feng, Rajesh Kumar Singh, Yucheng Fu, Zhuo Li, Yulong Wang, Jie Bao, Zhijie Xu, Guosheng Li, Cassidy Anderson, Lili Shi, Yuehe Lin, Peter G. Khalifah, Wei Wang, Jun Liu, Jie Xiao, Dongping Lu
Summary: In this study, a simple strategy was demonstrated for constructing low-tortuosity through-pores in both vertical and planar directions of electrodes by casting large particles into single-particle-layer electrodes. Through multi-scale characterizations and simulations, correlations between material/electrode structures, electrolyte permeability, polysulfide migration, and sulfur reactions were elucidated. The high-loading and dense sulfur cathode fabricated by this method delivers a high specific capacity at a very low electrolyte/sulfur ratio.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Rahmandhika Firdauzha Hary Hernandha, Bharath Umesh, Purna Chandra Rath, Le Thi Thu Trang, Ju-Chao Wei, Yu-Chun Chuang, Ju Li, Jeng-Kuei Chang
Summary: The lithiation/delithiation properties of alpha-Si3N4 and beta-Si3N4 are compared and the carbon coating effects are examined. Then, beta-Si3N4 at various fractions is used as the secondary phase in a Si anode to modify the electrode properties. The incorporated beta-Si3N4 decreases the crystal size of Si and introduces a new N-Si-O species at the beta-Si3N4/Si interface.
Article
Engineering, Environmental
Evert J. Elzinga
Summary: The study found that Ni(II) is incorporated into the lattice of green rust sulfate through recrystallization and exchange reactions, forming secondary Ni(II)/Fe(II)-Fe(III)-LDH phases with higher stability. Further research is needed to investigate the mechanisms involved and assess the sorptive reactivity of green rust with other trace metal species.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Polymer Science
Meri J. Lundahl, Daisuke Sawada, Markus Merila, Michael Hummel
Summary: The graphitization of biobased carbon fiber (CF) can be improved by including graphitic additives as structural templates in the precursor. The addition of graphene oxide (GO) thickened the solution and increased its elastic nature, while carbon nanotube (CNT) only moderately increased the elasticity. Both GO and CNT additives allowed for the spinning of continuous precursor fibers, although GO slightly disrupted cellulose alignment in the fiber. GO also induced structural order development and decreased the intensity and ratio of Raman peaks related to disorder and sp2-hybridized carbon.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Engineering, Chemical
Chitra Sivakumar, Jarvis A. Stobbs, Kaiyang Tu, Chithra Karunakaran, Jitendra Paliwal
Summary: This study investigates the molecular changes in roller-milled green lentil flours caused by mill settings and blending of fractions. The use of advanced techniques such as synchrotron X-rays, FTIR spectroscopy, and laser diffraction provides a deeper understanding of the particle size, crystallinity, and starch/protein quality differences between flour blends and streams. The development of a principal component analysis model allows for the classification of samples based on their carbohydrate and protein profiles. This research is crucial for the food industry to utilize pulse flours in the creation of nutritionally dense foods.
Article
Nanoscience & Nanotechnology
Zhengyu Yan, Amor Abdelkader, Sarah Day, Chiu Tang, Cinzia Casiraghi, Wajira Mirihanage
Summary: In this study, in situ synchrotron x-ray powder diffraction experiments were conducted on bulk h-BN up to 1273 K, revealing a potential thermal assisted exfoliation mechanism at high temperatures.
Article
Chemistry, Physical
Seungyong Shin, Sungjun Yang, Seong-hun Lee, Tae Joo Shin, Sangmoon Park
Summary: In this study, a barium yttrium orthogermanate luminescent host was synthesized and its application in Ce3+-doped phosphor-converted light-emitting diodes (pc-LEDs) under blue excitation was investigated. The structure of the host compound was determined, and the specific origin of the green-yellow luminescence was identified through various characterization techniques. The optical properties of the compound were evaluated, and the valence states of the alkali metal ions in the phosphors were determined.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Biochemistry & Molecular Biology
Danielle C. Teles-Ferreira, Cristian Manzoni, Lara Martinez-Fernandez, Giulio Cerullo, Ana Maria de Paula, Rocio Borrego-Varillas
Summary: Understanding the primary steps following UV photoexcitation in sulphur-substituted DNA bases is crucial for developing new phototherapeutic drugs. This study successfully tracks the ultrafast decay mechanisms in 6-thioguanine and provides experimental evidence of fast internal conversion and electron trapping in the triplet manifold.
Article
Chemistry, Multidisciplinary
Andrea Schirato, Giulia Crotti, Mychel Goncalves Silva, Danielle Cristina Teles-Ferreira, Cristian Manzoni, Remo Proietti Zaccaria, Paolo Laporta, Ana Maria de Paula, Giulio Cerullo, Giuseppe Della Valle
Summary: The transient optical response of plasmonic nanostructures is important for studying light harvesting, photocatalytic processes, nonlinear nanophotonics, and all-optical modulation. However, under a nonperturbative excitation regime, the correspondence between the temporal evolution of the dynamic optical signal and the photoexcited hot electrons is not valid.
Article
Chemistry, Multidisciplinary
Vishal Kumar Jaiswal, Piotr Kabacinski, Barbara E. Nogueira de Faria, Marziogiuseppe Gentile, Ana Maria de Paula, Rocio Borrego-Varillas, Artur Nenov, Irene Conti, Giulio Cerullo, Marco Garavelli
Summary: By combining UV transient absorption spectroscopy with sub-30-fs temporal resolution and CASPT2/MM calculations, this study provides a complete description of the primary photoinduced processes in solvated tryptophan. The role of the solvent in the relaxation dynamics of tryptophan is clarified, and evidence of vibrational coherence is presented.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Biochemical Research Methods
Egleidson F. A. Gomes, Eduardo Paulino Junior, Mario F. R. de Lima, Luana A. Reis, Giovanna Paranhos, Marcelo Mamede, Francis G. J. Longford, Jeremy G. Frey, Ana Maria de Paula
Summary: Prostate carcinoma, the second most common cancer among men worldwide, is often slow-growing and indolent. Prognosis relies heavily on the Gleason system, but new treatment and monitoring strategies require a more precise diagnosis. This study used multiphoton imaging to analyze prostate tumor samples from 120 patients, resulting in quantitative parameters that can indicate specific tumor aggressiveness signatures. The automated image analysis distinguished between non-neoplastic tissue and carcinoma areas with an accuracy of 89% +/- 3%, but only achieved 46% +/- 6% accuracy in differentiating between Gleason groups. However, the inclusion of stromal parameters improved the accuracy to 65% +/- 5%, highlighting the importance of considering these parameters for a more accurate diagnosis.
JOURNAL OF BIOPHOTONICS
(2023)
Review
Optics
Christiano J. S. De Matos, Enrique G. Rosa, Juan D. Zapata, David Steinberg, Melissa Maldonado, E. A. Thoroh De Souza, Ana M. De Paula, Leandro M. Malard, Anderson S. L. Gomes
Summary: This paper reviews the work carried out in the field of nonlinear optics in two-dimensional and ultrathin lamellar materials, with a special focus on contributions authored and co-authored by researchers affiliated with Latin American institutions. It is shown that important and impactful contributions have emerged from Latin America, which has a consolidated and active optics community. Nonlinear optical refraction, nonlinear optical absorption, and nonlinear frequency conversion in materials such as graphene, transition metal dichalcogenides, and black phosphorus are among the reviewed themes.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Andreij C. Gadelha, Joyce C. C. Santos, Cassiano Rabelo, Thiago L. Vasconcelos, Rafael S. Alencar, Vitor Monken, Hudson L. S. Miranda, Luiz A. Cury, Ygor M. Jaques, Raphael M. Tromer, Douglas S. Galvao, Luiz G. Cancado, Bernardo R. A. Neves, Ado Jorio
Summary: Hybrid organic/inorganic Van der Waals heterostructures have great potential applications in nanotechnology and industry. The interfacial effects in these heterostructures can modulate the final properties and open up possibilities for innovative device design and operation. This study investigates a hybrid organic/inorganic heterostructure of coronene and few-layers MoS2, and reveals localized enhancement of MoS2 optical properties at the edges and defects due to the assembling of coronene molecules in MoS2. The results provide insights for engineering molecules in two-dimensional nanomaterials and controlling optical phenomena.
Article
Materials Science, Multidisciplinary
Yuri Bernardes, Lucas A. B. Marcal, Barbara L. T. Rosa, Ailton Garcia Jr, Christoph Deneke, Tobias U. Schulli, Marie-Ingrid Richard, Angelo Malachias
Summary: Investigations on epitaxial nanostructures with size of tens of nanometers have been challenging for high strain sensitivity techniques with restricted spatial resolution, such as x-ray nanoprobe techniques. The diffraction limit imposes limitations on the voxel or pixel sizes obtained in coherent diffraction imaging or ptychographic reconstructions. However, the InGaAs/GaAs Stranski-Krastanov system provides a model to directly analyze and identify epitaxial systems with large lattice mismatch and appreciable interfacial strain by observing the strain-induced footprint along a few microns if the membrane thickness is comparable to the nanostructure size.
PHYSICAL REVIEW MATERIALS
(2023)
Review
Nanoscience & Nanotechnology
Gabriel Gomes, Marcos L. F. Gomes, Saimon F. Covre da Silva, Ailton Garcia Jr, Armando Rastelli, Odilon D. D. Couto Jr, Angelo Malachias, Christoph Deneke
Summary: This review discusses the influence of the inherently asymmetric strain state of rolled-up III-V heterostructure tubes on light emitters. Whispering gallery mode resonators built from rolled-up III-V heterostructures are briefly reviewed. The curvature and its influence on the diameter of the rolled-up micro- and nanotubes are discussed, as well as the possible strain states. Experimental techniques are essential to accurately determine the strain state for the emitters inside the tube wall.
Article
Materials Science, Multidisciplinary
Lucas Polesi, Everton Pereira de Andrade, Angelo Malachias, Luiz Alberto Cury, Gustavo de Almeida Magalha Safar
Summary: In this study, ultrasonic nebulization is investigated as a useful technique for producing ultrathin films of small molecules. The method is applicable to a variety of substrates, especially with low viscosity solvents like water. We examine the quantitative results of the ultrasonic nebulization technique for film growth under mild conditions to fabricate ultrathin films of perylenetetracarboxylate derivatives.
ORGANIC ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Andrea Schirato, Mychel G. Silva, Danielle C. Teles-Ferreira, Cristian Manzoni, Ana Maria de Paula, Giulio Cerullo, Giuseppe Della Valle, Marcel Di Vece
Summary: The photoexcitation of plasmonic nanostructures with ultrashort laser pulses allows for understanding the ultrafast nonlinear optical response and fundamental processes triggered by light absorption. The effects of photoexcitation on plasmonic nanostructures are studied using broadband transient absorption spectroscopy and semiclassical nonlinear simulations. The results provide a comprehensive understanding of the thermo-modulational nonlinearities of plasmonic nanostructures exhibiting resonances close to the interband transition threshold.
ADVANCED PHOTONICS RESEARCH
(2023)
Article
Optics
Weder Junior Elias de Paula, Gustavo de Almeida Magalhaes Safar, Eufranio N. da Silva Jr, Luiz A. Cury
Summary: This study investigates phosphorescent emissions at room temperature from a solid-state self sustained film fabricated using phenazine derivative molecules blended in a solution of poly(methyl methacrylate). The results show that the film exhibits relatively higher gain characteristics for triplet state excitons, enabling waveguided emission. The analysis of the emission spectra indicates a relatively higher contribution of the total integrated area for the phosphorescent part.
JOURNAL OF LUMINESCENCE
(2024)
Article
Chemistry, Physical
Danielle Cristina Teles-Ferreira, Ivo Hm van Stokkum, Irene Conti, Lucia Ganzer, Cristian Manzoni, Marco Garavelli, Giulio Cerullo, Artur Nenov, Rocio Borrego-Varillas, Ana Maria de Paula
Summary: This study investigates the mechanism of thionated nucleobases' ultrafast transition from singlet states to triplet states using transient absorption spectroscopy. Experimental results combined with theoretical simulations suggest that the relaxation to the triplet state is mediated by conical intersections promoted by vibrational coherences through the population of an intermediate singlet state.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
