Article
Engineering, Electrical & Electronic
R. A. Ejbarah, J. M. Jassim, S. M. Hamidi
Summary: This study investigated the impact of dye concentration, cell thickness, and polymers on the characteristics of random lasers, revealing significant effects on parameters such as emission spectrum, FWHM, and lasing threshold. By optimizing these parameters, improvements in the random laser properties were achieved, showing promise for potential applications in medical devices and biosensors.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Optics
Mandana Sadat Hosseini, Elnaz Yazdani, Batool Sajad, Fariba Mehradnia
Summary: The study reveals that the coupling of random lasing and stimulated Raman scattering enables tunable random lasers, offering possibilities for manufacturing optical devices in the future. This coupling effect also aids in enhancing the efficiency and applications of Raman spectroscopy.
JOURNAL OF LUMINESCENCE
(2021)
Article
Biochemistry & Molecular Biology
Magdalena Laskowska, Agnieszka Karczmarska, Mateusz Schabikowski, Michal Adamek, Alexey Maximenko, Katarzyna Pawlik, Oliwia Kowalska, Zbigniew Olejniczak, Lukasz Laskowski
Summary: The effects of synthesis conditions on the size and structure of synthetic opals were investigated using the Stober process. The internal hierarchical structure of the resulting silica particles was confirmed, and the study showed no dependence on the concentration of reagents and the size of the particles. This research is significant for the synthesis and application of synthetic opals.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Chemistry, Multidisciplinary
Clemence Cheignon, Ali A. Kassir, Lohona K. Soro, Loic J. Charbonniere
Summary: This article reviews the application of lanthanide complexes in spectroscopy. By utilizing the antenna effect brought by organic ligands, the low brightness caused by forbidden Ln electronic transitions can be overcome. Furthermore, the design progress of nano-objects with multiple lanthanide ions and their spectroscopic properties are discussed.
Article
Pharmacology & Pharmacy
Pedro Martins da Silva Filho, Pedro Higor Rocha Mariano, Alexandre Lopes Andrade, Jessica Barros Arrais Cruz Lopes, Aryane de Azevedo Pinheiro, Mayara Itala Geronimo de Azevedo, Suelen Carneiro de Medeiros, Mayron Alves de Vasconcelos, Said Goncalvez da Cruz Fonseca, Thalles Barbosa Grangeiro, Luiz Gonzaga de Franca, Eduardo Henrique Silva Sousa, Edson Holanda Teixeira, Elisane Longhinotti
Summary: New antibiotic agents are urgently needed worldwide to combat the increasing tolerance and resistance of pathogenic fungi and bacteria to current antimicrobials. The study found that minor quantities of cetyltrimethylammonium bromide (CTAB) on silica nanoparticles exhibit antimicrobial activity against Methicillin-resistant Staphylococcus aureus strain and reference strains of Candida. The results also showed low cytotoxicity in human fibroblasts and potential application in the treatment and/or prevention of infections caused by drug-resistant Staphylococcus and Candida species.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Materials Science, Multidisciplinary
Abdullah M. Alswieleh
Summary: A polymer brush derived from poly(2-(tert-butylamino)ethyl methacrylate)-coated mesoporous silica nanoparticles (PTBAEMA-SO3H@MSNPs) was successfully fabricated in this study. The structure and morphology of PTBAEMA-SO3H@ MSNPs were analyzed using various techniques, including transmission electron microscopy and Fourier-transform infrared spectroscopy. The optimal conditions for the removal of rhodamine B (Rh B) and crystal violet (CV) were determined, and the adsorption equilibrium was fitted with different isotherm models. The study found that PTBAEMA-SO3H@MSNPs are highly effective in removing Rh B and CV from water samples.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Physics, Multidisciplinary
R. A. Ejbarah, J. M. Jassim, H. Yazdanfar, S. M. Hamidi
Summary: A new type of random lasing media based on silver nano-hexagonal scattering centers was demonstrated to reduce the threshold for dye-based random lasers. By synthesizing nano hexagonal silver scatterer points and dissolving them in polymer and Rhodamine B dye media in different concentrations and sizes, it was found that the threshold power and linewidths of emission peaks decreased with an increase in the size and concentrations of nano-hexagonal points.
Article
Chemistry, Physical
Menglu Li, Nianmin Hong, Jian Jiang, Wenxin Fu
Summary: This study investigated the preparation mechanism of monodispersed hollow silica nanoparticles (HSNs) using a template strategy. It was found that only positively charged polystyrene (PS) templates could induce the deposition of hydrolyzed silicon source and promote the growth of SiO2 shells through the condensation of silanol groups. This research provides detailed insights into the formation process and mechanism of HSNs.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Inorganic & Nuclear
Pavlo Sivolapov, Oleksiy Myronyuk, Denys Baklan
Summary: Stober synthesis is the most commonly used technique to control the size of SiO2 nanoparticles. In this paper, a series of Stober syntheses in media with different thermodynamic parameters were carried out, and the obtained nanoparticles were characterized using electron microscopy. The results showed that the variation of solvent in Stober synthesis is an effective tool for controlling the particle size of silica. The addition of nonpolar liquids resulted in smaller particles, while an increase in the dispersion and polar parameters of the solvent led to an increase in the size of the resulting SiO2 nanoparticles.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Hiresh Moradi, Peyman Atashi, Omid Amelirad, Jae-Kyu Yang, Yoon-Young Chang, Telma Kamranifard
Summary: This study synthesized monodispersed silica nanoparticles directly from TEOS using the sol-gel process and the Stober method. By optimizing the process with a central composite design, the smallest particle size and lowest TEOS concentration were achieved. The results showed that the predicted optimization was consistent with experimental procedures and the model was significant at a 95% confidence level.
ADVANCES IN NANO RESEARCH
(2022)
Article
Physics, Multidisciplinary
Shen Yan-Li, Shi Bing-Rong, Lu Hao, Zhang Shuai-Yi, Wang Xia
Summary: The graphene and nanoparticles composites show unique optical and electrical properties, making them widely used in information sensing, photoelectric conversion, and medical diagnosis. This study focuses on the preparation of Au/graphene structures and investigates their random laser properties. The results demonstrate that the addition of graphene reduces the laser threshold and enhances the surface plasmon resonance effect, contributing to the improved performance of optoelectronic devices.
ACTA PHYSICA SINICA
(2022)
Article
Nanoscience & Nanotechnology
Lech Sznitko, Tarek Chtouki, Bouchta Sahraoui, Jaroslaw Mysliwiec
Summary: This article investigates the effect of excitation wavelength on random laser emission in a dye-doped polymeric system. Changing the pumping wavelength can switch the emission between lasing bands and control their relative intensity. The random lasing phenomenon influences the resulting bichromatic emission and randomly selects the dominating lasing band.
Article
Chemistry, Multidisciplinary
Yan Zhang, Chenglin Yi, Wenhao Dong, Di Zheng, Yiqun Yang, Wei Li, Xiaozheng Duan, Dong Yang, Zhihong Nie
Summary: This study presents a general strategy for the scalable synthesis of highly monodisperse silica-based nanoparticles (SNPs) with sub-50 nm diameter. By utilizing copolymers as templates, ultrasmall single-chain nanoparticles are formed and used as seeds for the production of uniform SNPs. The composition and architecture of the copolymers play a crucial role in the formation of the seeds and the uniform deposition of silica. The study also demonstrates the ability to produce asymmetric Janus-like and dumbbell-like SNPs by tailoring the copolymer architecture.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Ceramics
Nadja Klippel, Gregor Jung, Guido Kickelbick
Summary: This study investigated the incorporation mechanisms of fluorescent dyes in silica nanoparticles and found that covalent bonding is necessary for fluorescence stability. The use of protective layers can reduce dye leaching.
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Christian Sogaard, Krzysztof Kolman, Max Christensson, Ayse Birsen Otyakmaz, Zareen Abbas
Summary: Understanding the interaction of ions with charged silica nanoparticles is crucial for producing gels and determining long term stability. In mixtures, monovalent ions generally follow the Hofmeister series, but divalent ions do not. At pH < 9, mixtures of divalent and monovalent salts follow the normal Hofmeister series, while at pH > 9 a reversal is observed.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Engineering, Biomedical
Laura M. S. dos Santos, Jonathas M. de Oliveira, Elaine C. O. da Silva, Vitor M. L. Fonseca, Juliane P. Silva, Emiliano Barreto, Noelio Oliveira Dantas, Anielle C. A. Silva, Alcenisio J. Jesus-Silva, Cleber R. Mendonca, Eduardo J. S. Fonseca
Summary: Microgrooved surfaces created by femtosecond laser writing technique were investigated for their mechanical and morphological effects on osteoblast cells. Circular microgrooves were found to enhance osteoblast alignment and stiffness, while the incorporation of TiO2 nanocrystals further improved the effects of circular microgrooves.
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A
(2023)
Article
Optics
Luiz M. M. Barreto, Davinson M. da Silva, Antonio D. Santos, Koiti Araki, Cid B. de Araujo, Luciana R. P. Kassab
Summary: Multilayer graphene (MLG) thin films were produced by depositing them on a cobalt buffer-layer prepared at 500 degrees C and subsequently thermal annealing. The annealing process allowed the transformation of amorphous carbon to graphene through diffusion and nucleation. The thicknesses of the cobalt and MLG thin films were measured as 55 and 54 nm, respectively, by atomic force microscopy. Raman spectroscopy confirmed the presence of MLG based on the intensity ratio of the 2D and G bands (I2D/IG), which was found to be 0.4 for the annealed graphene thin film. Additional analysis using transmission electron microscopy supported the Raman results. Moreover, the MLG films exhibited significant nonlinear absorption behavior at 980 nm and can be utilized as optical limiters.
Article
Optics
Josivanir G. Camara, Davinson M. Da Silva, Luciana R. P. Kassab, Cid B. De Araujo
Summary: Random lasing is observed in neodymium doped alumina lead-germanate glass powder for the first time. The samples were fabricated using a conventional melt-quenching technique and confirmed to have an amorphous structure. Excitation of the sample at 808 nm resulted in random laser emission at 1060 nm, with an excitation energy fluence threshold of 0.3 mJ/mm2. The use of large quantities of neodymium oxide in the glass did not hinder the laser emission process, despite luminescence concentration quenching.
Article
Nanoscience & Nanotechnology
Jessica E. Q. . Bautista, Cecilia L. A. . V. Campos, Manoel L. da Silva-Neto, Cid B. de Araujo, Ali M. Jawaid, Robert Busch, Richard A. Vaia, Anderson S. L. Gomes
Summary: Experimental studies were conducted on spatial self-phase modulation (SSPM) in liquid suspensions of various materials using different light polarization and excitation lasers. The changes in refractive index and ring formation were explained as thermal effects. The measured thermal nonlinear coefficients were independent of the optical excitation regime. The use of circularly polarized light provided complementary results to linearly polarized light.
Article
Chemistry, Multidisciplinary
Leandra P. Santos, Diana Lermen, Rafael Galiza Yoshimura, Bruno Leuzinger da Silva, Andre Galembeck, Thiago A. L. Burgo, Fernando Galembeck
Summary: Hygroelectric cells can simultaneously deliver hydrogen, hydrogen peroxide, and electric current from liquid water or vapor at room temperature. Water dehydrogenation is a non-spontaneous reaction under standard conditions but can occur in an open, non-electroneutral system, supporting the experimental results. This research provides a new example of chemical reactivity modification in charged interfaces and has the potential to predict unexpected new chemical reactions through experimental methods and thermodynamic analysis. Hygroelectric cells, built from common materials using scalable processes, may eventually become a source of energy and valuable chemicals.
Article
Chemistry, Physical
Maxwell A. M. Nogueira, Albert S. Reyna, Helivaldo D. S. Souza, Bruno F. Lira, Petronio F. de Athayde-Filho, Cid B. B. de Araujo
Summary: We synthesized a mesoionic compound and investigated its nonlinear optical response in terms of refractive and absorptive properties in different temporal and spectral regimes. Z-scan technique was used with two pulsed light sources: a mode-locked and Q-switched Nd-YAG laser at 532 nm and a Ti: Sapphire laser system at 800 nm. The compound's nonlinear refraction, two- and three-photon absorption, and excited state absorption were observed and characterized based on a three-energy-level model, allowing the determination of the parameters that describe the nonlinear response.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Materials Science, Multidisciplinary
Luz Patricia Naranjo-Riano, Nathalia T. C. Oliveria, Camilo E. Echeverry, Luciana R. P. Kassab, Cid B. de Araujo
Summary: We synthesized and characterized PbO-Bi2O3-Ga2O3 glass-ceramics containing PbO and Bi2O3 crystallites, free Pb2+ and Bi3+ ions, and Ag-NPs. The samples were prepared using the melt-quenching method followed by heat treatment. Various techniques were used for characterization, including transmission electron microscopy, X-ray diffraction, linear optical absorption, and photoluminescence (PL). Excitation at 330 nm resulted in a large PL intensity due to Pb2+ and Bi3+. Additionally, the PL intensity was enhanced by about 1000% in samples containing Ag-NPs compared to those without Ag-NPs. This behavior is reported for the first time in heavy-metal oxide glass-ceramics, highlighting the potential for photonic applications.
Article
Optics
Andre C. A. Siqueira, Guillermo Palacios, Albert S. Reyna, Boris A. Malomed, Edilson L. Falcao-Filho, Cid B. de Araujo
Summary: We present the results of a numerical analysis comparing the efficiency of the multiple temporal compression (MTC) method with conventional methods using photonic crystal fibers (PCFs) and fused silica waveguides (FSWs) for generating multiple solitons. The analysis shows that the MTC method is more efficient in controlling soliton fission, resulting in a larger number of high-powered fundamental solitons that remain stable over long distances. The high efficiency of the MTC method is particularly evident in multiple soliton collisions and the Newton's-cradle phenomenology.
OPTICS COMMUNICATIONS
(2023)
Review
Chemistry, Multidisciplinary
Anderson S. L. Gomes, Cecilia L. A. V. Campos, Cid B. de Araujo, Melissa Maldonado, Manoel L. da Silva-Neto, Ali M. Jawaid, Robert Busch, Richard A. Vaia
Summary: In this article, we review our work on the nonlinear optical response of a series of 2D-LTMDs nanomaterials using six different NLO techniques. We studied the nonlinear response of various materials and measured the nonlinear refraction index and absorption coefficient. Theoretical support was also provided to explain the origin of the nonlinear responses.
Article
Optics
Guillermo Palacios, Andre C. A. Siqueira, Cid B. de Araujo, Anderson S. L. Gomes, Ernesto P. Raposo
Summary: In this study, the phenomenon of replica symmetry breaking (RSB) was investigated in random lasers (RLs) through Monte Carlo simulations. The study revealed that photonic random walkers diffuse and get randomly scattered in the active medium, interacting with both the population of excited atoms and each other. When the interactions among photonic walkers are not included, a replica-symmetric distribution for the Parisi overlap parameter (P(q)) at q = 0 is found for any excitation energy. The study also examined the statistical correlations of intensity fluctuations in different modes of the same spectrum, finding consistency with experimental results in RL materials.
Article
Nanoscience & Nanotechnology
Jessica E. Q. Bautista, Cecilia L. A. V. Campos, Manoel L. da Silva-Neto, Cid B. de Araujo, Ali M. Jawaid, Robert Busch, Richard A. Vaia, Anderson S. L. Gomes
Summary: We experimentally studied spatial self-phase modulation (SSPM) in liquid suspensions of various 2D materials. The intensity-dependent changes in refractive index responsible for SSPM are shown to be due to thermal effects. The measured thermal nonlinear coefficients for different suspensions are independent of the excitation regime. The use of circularly polarized light complements the results obtained with linearly polarized light.
Article
Chemistry, Physical
Manoel L. Silva-Neto, Renato Barbosa-Silva, Georges Boudebs, Cid B. de Araujo
Summary: This study determined the first hyperpolarizability of graphene quantum dots (GQDs) suspended in water using the hyper-Rayleigh scattering (HRS) technique. The results suggest that these GQDs may have potential applications in biological microscopy imaging.
Article
Materials Science, Multidisciplinary
Renato Barbosa-Silva, Mario S. S. Oliveira, Rudson C. Ferreira, Vinicius Manzoni, Eduardo H. L. Falcao, Cid B. de Araujo
Summary: Measurements and theoretical modeling of the second-order optical nonlinearity of two 1,3,4-oxadiazole derivatives, Oxa-4-Py and DiOxaBn-2-Tio, were reported. The dynamic and static first hyperpolarizability values were measured using the hyper-Rayleigh scattering technique and a density functional method. The results showed that the first hyperpolarizability of DiOxaBn-2-Tio is approximately 30% larger than that of Oxa-4-Py.
Article
Optics
Andre C. A. Siqueira, Edilson L. Falcao-Filho, Boris A. Malomed, Cid B. de Araujo
Summary: Theoretical consideration and numerical simulation of femtosecond pulse propagation in a one-dimensional composite medium reveals the generation of bright soliton trains. The paper discusses the controllable production of ultrashort temporal solitons and addresses the role of intrapulse Raman scattering and collisions between solitons with different central wavelengths.
Article
Chemistry, Analytical
Felix Mayr, Robert Zimmerleiter, Patricia M. A. Farias, Mateusz Bednorz, Yolanda Salinas, Andre Galembek, Olavo D. F. Cardozo, Dominik Wielend, Dyego Oliveira, Raquel Milani, Tania M. Brito-Silva, Markus Brandstetter, Eduardo Padron-Hernandez, Peter Burgholzer, Andreas Stingl, Markus C. Scharber, Niyazi Serdar Sariciftci
Summary: Surface-enhanced Raman scattering (SERS) is a sensitive and fast technique for chemical trace analysis. This study presents a robust, reproducible, flexible, and cost-effective SERS substrate for sensitive detection in the near-infrared (NIR) range. The substrate can withstand high laser power while maintaining a linear signal response, enabling high signal enhancement potential.
ANALYTICAL SCIENCE ADVANCES
(2023)