scholarly journals Controlled size and high stability SiO2@ZnO QD’s with high green emission obtained by a simple colloidal route

2019 ◽  
Author(s):  
Rene Perez Cuapio ◽  
Jose Alberto A G Alvarado Garcia ◽  
Mauricio Pacio Castillo ◽  
Antonio Arce Plaza ◽  
Carlos Bueno Avendaño ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Green Emission ◽  
Morphological Characterization ◽  
The Core ◽  
Ft Ir ◽  
Uv Lamp ◽  
Size And Morphology ◽  
The Stability ◽  
Average Size

In this work the synthesis of visible ZnO quantum dots (QDs) functionalized/stabilized with oleic acid and core-shelled with SiO2 is presented. A colloidal route was followed to synthesize ZnO QDs with 5 nm average size. Several characterizations were done to identify and assure the core, the stabilization, grain size and QDs emission characteristics. Techniques like FT-IR, XRD, TEM, SEM, UV-Vis, PL and an UV lamp were used to test composition, structural, morphological and emission of the as obtained quantum dots. After the structural and morphological characterization of the particles, they were functionalized with (3-aminopropyl) trimethoxysilane (APTMS).  It was observed that the size and morphology are unchanged but the stability depends directly on the APTMS oversaturation which is due to the formation of a thick SiO2 layer. From the PL characterization results it was noticed that the strong green emission is related to the APTMS content and directly related to the shell formation, this emission decreases as the core-shell thickness increases.

scholarly journals Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 303
Author(s):  
Rokayya Sami ◽  
Schahrazad Soltane ◽  
Mahmoud Helal
Keyword(s):  
Ph Value ◽  
Silica Nanoparticle ◽  
Morphological Characterization ◽  
Aerobic Bacteria ◽  
Nano Materials ◽  
Elongation At Break ◽  
Stable Suspension ◽  
Average Size ◽  
Material Ductility

In the current work, the characterization of novel chitosan/silica nanoparticle/nisin films with the addition of nisin as an antimicrobial technique for blueberry preservation during storage is investigated. Chitosan/Silica Nanoparticle/N (CH-SN-N) films presented a stable suspension as the surface loads (45.9 mV) and the distribution was considered broad (0.62). The result shows that the pH value was increased gradually with the addition of nisin to 4.12, while the turbidity was the highest at 0.39. The content of the insoluble matter and contact angle were the highest for the Chitosan/Silica Nanoparticle (CH-SN) film at 5.68%. The use of nano-materials in chitosan films decreased the material ductility, reduced the tensile strength and elongation-at-break of the membrane. The coated blueberries with Chitosan/Silica Nanoparticle/N films reported the lowest microbial contamination counts at 2.82 log CFU/g followed by Chitosan/Silica Nanoparticle at 3.73 and 3.58 log CFU/g for the aerobic bacteria, molds, and yeasts population, respectively. It was observed that (CH) film extracted 94 regions with an average size of 449.10, at the same time (CH-SN) film extracted 169 regions with an average size of 130.53. The (CH-SN-N) film presented the best result at 5.19%. It could be observed that the size of the total region of the fruit for the (CH) case was the smallest (1663 pixels), which implied that the fruit lost moisture content. As a conclusion, (CH-SN-N) film is recommended for blueberry preservation to prolong the shelf-life during storage.

scholarly journals Síntese, caracterização e estabilidade de nanopartículas de magnetita

2021 ◽  
Vol 3 (4) ◽  
pp. 2738-2749
Author(s):  
Monise Cristina Ribeiro Casanova Coltro ◽  
Warde Antonieta da Fonseca-Zang ◽  
Joachim Werner Zang ◽  
Danilo César Silva e Sousa
Keyword(s):  
New Technology ◽  
X Ray Diffraction ◽  
Synthesis Of Nanoparticles ◽  
Research Areas ◽  
Magnetite Fe3o4 ◽  
Mineral Substance ◽  
Abundant Element ◽  
The Stability ◽  
Average Size

Nanopartículas de ferro são muito utilizadas em diversas áreas de pesquisa. O elemento químico ferro (Fe), sendo o quarto elemento mais abundante na crosta terrestre, e a substância mineral magnetita, com propriedade magnética, apresentam aplicações nas áreas industrial, ambiental, biomédica e de novas tecnologias. Este trabalho apresenta processo de síntese de nanopartículas partindo-se de sais precursores, bem como a caracterização dos produtos e as rotas para estabilizá-los. Os sais químicos precursores utilizados foram o cloreto férrico (FeCl3) e o sulfato ferroso (FeSO4) na proporção de 2:1, sob agitação por ultrassom e pH ácido. Para formação do precipitado de nanopartículas usou-se solução aquosa de hidróxido de sódio (NaOH) de pH 12. A difratometria de raio-X, mostra a presença de magnetita (Fe3O4) indicada pelos picos característicos de difração em graus 2Ө = 18° (largo), 31° (fino), 36° (bem definido), 43,4°, 45°, 53,6°, 57,7°, 63,3°. A microscopia eletrônica de transmissão mostra a morfologia dos produtos da síntese. Fatores que influenciam a estabilidade das partículas são agitação, o ajuste de pH, condições de secagem. O tamanho médio das nanopartículas de magnetitas é de aproximadamente 15 nm.   Iron nanoparticles are widely used in several research areas. The chemical element iron (Fe), being the fourth most abundant element in the earth's crust, and the mineral substance magnetite, with magnetic properties, have applications in industrial, environmental, biomedical, and new technology areas. This work presents the process of synthesis of nanoparticles starting from precursor salts, as well as the characterization of the products and the routes to stabilize them. The precursor chemical salts were ferric chloride (FeCl3) and ferrous sulfate (FeSO4) in a 2:1 ratio, under ultrasound agitation and acidic pH. For the nanoparticles growth was applied aqueous solution of sodium hydroxide (NaOH) at pH 12. X-ray diffraction shows the presence of magnetite (Fe3O4) indicated by characteristic diffraction peaks in degrees 2Ө = 18° (wide), 31° (fine), 36° (well defined), 43.4°, 45°, 53.6°, 57.7°, 63.3°. Scanning electron microscopy shows the morphology of the synthesis products. Factors that influence the stability of the particles are agitation, the pH adjustment, and the conditions of drying. The average size of the magnetite nanoparticles is approximately 15 nm.

Study on the Synthesis and Characterization of PANi/Nano-CeO2 Composites

2007 ◽  
Vol 124-126 ◽  
pp. 287-290 ◽  
Author(s):  
Fei Liu ◽  
Yong Jun He ◽  
Jeung Soo Huh
Keyword(s):  
In Situ Polymerization ◽  
Solid Phase ◽  
Polymerization Reaction ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Average Size

The nano-CeO2 was synthesized by two-step solid-phase reaction. The image of TEM showed that nano-CeO2 with an average size of about 70 nm. The series of polyaniline/nano-CeO2 composites with different PANi: CeO2 ratios were prepared by in-situ polymerization in the presence of hydrochloric acid (HCl) as dopant by adding nano-CeO2 into the polymerization reaction mixture of aniline. The composites obtained were characterized by FT-IR and UV-vis spectroscopy analysis. The FT-IR spectra of nanocomposites indicate different blue-shifts, attributed to C–N stretching mode for benzenoid unit. The UV-vis spectra of nanocomposites display einstein-shifts compared with PANi at 620nm. The conductivity properties of the composites are also changed compare to the pure PANi. These results suggest that the interactions between the polymer matrix and nanoparticles take place in polyaniline/nano- CeO2 composites.

scholarly journals Identification and Characterization of Citrus Chlorotic Spot Virus, a New Dichorhavirus Associated with Citrus Leprosis-Like Symptoms

Plant Disease ◽  
2018 ◽  
Vol 102 (8) ◽  
pp. 1588-1598 ◽  
Author(s):  
C. Chabi-Jesus ◽  
P. L. Ramos-González ◽  
A. D. Tassi ◽  
O. Guerra-Peraza ◽  
E. W. Kitajima ◽  
...  
Keyword(s):  
Virus Strain ◽  
Viral Vectors ◽  
Morphological Characterization ◽  
Spot Virus ◽  
Chlorotic Spot ◽  
Bipartite Genome ◽  
Citrus Leprosis ◽  
Average Size ◽  
Parenchymal Cells

Local chlorotic spots resembling early lesions characteristic of citrus leprosis (CL) were observed in leaves of two sweet orange (Citrus sinensis L.) trees in Teresina, State of Piauí, Brazil, in early 2017. However, despite the similarities, these spots were generally larger than those of a typical CL and showed rare or no necrosis symptoms. In symptomatic tissues, transmission electron microscopy revealed the presence of viroplasms in the nuclei of the infected parenchymal cells and rod-shaped particles with an average size of approximately 40 × 100 nm, resembling those typically observed during infection by dichorhaviruses. A bipartite genome of the putative novel virus, tentatively named citrus chlorotic spot virus (CiCSV) (RNA1 = 6,518 nucleotides [nt] and RNA2 = 5,987 nt), revealed the highest nucleotide sequence identity values with the dichorhaviruses coffee ringspot virus strain Lavras (73.8%), citrus leprosis virus N strain Ibi1 (58.6%), and orchid fleck virus strain So (56.9%). In addition to citrus, CiCSV was also found in local chlorotic lesions on leaves of the ornamental plant beach hibiscus (Talipariti tiliaceum (L.) Fryxell). Morphological characterization of mites recovered from the infected plants revealed at least two different types of Brevipalpus. One of them corresponds to Brevipalpus yothersi. The other is slightly different from B. yothersi mites but comprises traits that possibly place it as another species. A mix of the two mite types collected on beach hibiscus successfully transmitted CiCSV to arabidopsis plants but additional work is required to verify whether both types of flat mite may act as viral vectors. The current study reveals a newly described dichorhavirus associated with a citrus disease in the northeastern region of Brazil.

scholarly journals Physicochemical Characterization Of The Multiuse Medical Textiles In Surgery And As Packaging Material In Medical Sterilization

2017 ◽  
Vol 17 (3) ◽  
pp. 206-212 ◽  
Author(s):  
Beti Rogina-Car ◽  
Sandra Flincec Grgac ◽  
Drago Katovic
Keyword(s):  
Fourier Transform ◽  
Structural Characteristics ◽  
Physicochemical Characterization ◽  
Morphological Characterization ◽  
Packaging Material ◽  
Medical Textiles ◽  
Ft Ir ◽  
Continuous Use ◽  
Electronic Microscope

AbstractThis work investigates changes in the physicochemical properties of dry multiuse medical textiles used in surgery and as packaging material in sterilization after 0, 1, 10, 20, 30, and 50 washing and sterilization cycles in real hospital conditions of the Clinical-Hospital Centre in Zagreb. Scanning electronic microscope (SEM) was used to perform morphological characterization. Physicochemical characterization and the resulting changes in the medical textiles were monitored using Fourier transform infrared (FT-IR) spectrometer. The change in the mass of the medical textiles as a results of temperature was determined by thermogravimetric (TG) analysis. Furthermore, structural characteristics based on the changes that resulted during the washing and sterilization processes are provided. The conclusion of the conducted research on the changes in the properties of multiuse medical textiles (Cotton/PES, Tencel®, and three-layer PES/PU/PES textile laminate) in real hospital conditions is that the medical textiles do manage to preserve properties after continuous use and it is safe to use them up to 50 washing and sterilization cycles.

Incidence of the core composition on the stability, the ROS production and the toxicity of CdSe quantum dots

2014 ◽  
Vol 268 ◽  
pp. 246-255 ◽  
Author(s):  
Florence-Anaïs Kauffer ◽  
Christophe Merlin ◽  
Lavinia Balan ◽  
Raphaël Schneider
Keyword(s):  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
Ros Production ◽  
The Core ◽  
Core Composition ◽  
The Stability

scholarly journals Design and Characterization of Endostatin-Loaded Nanoparticles for In Vitro Antiangiogenesis in Squamous Cell Carcinoma

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Samson A. Adeyemi ◽  
Yahya E. Choonara ◽  
Pradeep Kumar ◽  
Lisa C. du Toit ◽  
Viness Pillay
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Viability ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Antiangiogenic Effect ◽  
Tumor Ph ◽  
Ft Ir ◽  
Average Size

The aim of this study is to effectively enhance antitumor activities of endostatin by preparing polymeric nanocarriers. NMR and FT-IR spectra confirmed the successful grafting of the CHT-g-PEI and CHT-g-PEI-PEG-NH2 conjugates. SEM micrographs confirmed the shape of endostatin-loaded nanoparticles to be spherical while both TEM and zeta size results showed nanoparticle’s average size to be 100.6 nm having a positively charged surface with zeta potential of 7.95 mV. The concentrations of CHT and TPP as well as the changing pH conditions account for the increased swelling pattern of endostatin-loaded nanoparticles and influenced endostatin release in vitro. PEI increased the overall amine protonation while PEG aggravated endostatin encapsulation and release. Nanoparticles swell and release endostatin at acidic tumor pH of 6.8 compared to physiological pH of 7.4. The native CHT-g-PEI-PEG-NH2 conjugate showed high cytocompatibility above 80% cell viability across tested formulations. Endostatin-loaded nanoparticles showed a significant reduction in cell viability across tested formulations, with 5.32% cell death at 125 μg/mL and 13.36% at 250 μg/mL following 24 hours’ incubation period. Interestingly, more than a fourfold (61.68%) increment in cytotoxicity was observed at nanoparticle concentration of 1000 μg/mL. It was concluded that CHT-g-PEI-PEG-NH2 is an effective cargo for endostatin delivery with antiangiogenic effect in squamous cell carcinoma.

Synthesis and Characterization of Hollow Silica via PMMA as Template

2006 ◽  
Vol 11-12 ◽  
pp. 551-554 ◽  
Author(s):  
Ji Rui Song ◽  
Li Xiong Wen ◽  
Jian Feng Chen ◽  
Hao Min Ding
Keyword(s):  
Shell Structures ◽  
Hollow Silica ◽  
Uniform Coating ◽  
The Core ◽  
Hollow Silica Spheres ◽  
Promising Agent ◽  
New Material ◽  
Ft Ir ◽  
Hydrolysis Of

Submicrosized porous hollow silica spheres with a diameter of 350 nm and a shell thickness of approximately 10 nm were synthesized by a hydrothermal method using PMMA hollow particles as template. Through the hydrolysis of TEOS, a continuous and uniform coating of SiO2 was deposited over the surface of PMMA cores to form the core-shell structures. After calcining to remove the template, a pure hollow silica structure with holes in the shells was obtained. The as-prepared hollow products were characterized with TEM, SEM, EDS, BET and FT-IR. Its large surface area and hollow morphology will make this new material a promising agent for the applications of catalysts, controlled drug delivery and etc.

The Study and Characterization of a Novel Structure of 1,3,5-Benzenetricarboxylic Acid

2013 ◽  
Vol 830 ◽  
pp. 202-206
Author(s):  
Hai Yan Tan ◽  
Cheng Liu ◽  
Jin Ping Wu
Keyword(s):  
Relevant Information ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Novel Structure ◽  
Ft Ir ◽  
Benzenetricarboxylic Acid ◽  
The Stability ◽  
Lamella Structure

A novel ten-interpenetrating structure of 1,3,5-benzenetricarboxylic acid was grown under solvothemal condition after heated it 16 hours. It was characterized by FT-IR, HNMR, X-ray diffraction, HRTEM. HRTEM obtain the relevant information of structural morphologies. The result of HRTEM showsed this material owned special lamella structure. X-ray diffraction showed the crystal of the new structure is of monoclinic system, space groupP1 with a=26.5039(17), b=16.4121(17),c=26.550(2)Å,α=90.00, β=91.533(2), γ=90.00, V=11544.4(17)Å3, Z=8, Dc=1.451g/cm3,μ=0.126mm-1,F(000)=5184, R=0.0891 and w (R)=0.1819 for 11318 observed reflection with I>2(I),hydrogen bond contributed to the stability of the structure. The fluorescence spectra indicated that the title compound had two stronger emission peak at 346nm and 400nm. Keywords:1, 3, 5-benzenetricarboxylic acid; novel structure; ten-interpenetrating

scholarly journals Preparation and characterization of highly blue emitting fluorescent carbon nano-dots using Pongammia pinnata fresh leaves

2021 ◽  
Author(s):  
Govindaraju K ◽  
K. Vijai Anand ◽  
S. Muthamilselvan ◽  
M. Kannan ◽  
M. Elanchezhiyan
Keyword(s):  
Electron Microscopy ◽  
Water Soluble ◽  
Hydrothermal Technique ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Average Size ◽  
Soluble Carbon ◽  
Ft Ir Spectroscopy

Abstract In this study, a simple environmental benign approach have been adopted for the preparation of highly luminescent (blue emitting) water soluble carbon nano-dots using Pongammia pinnata (Pp) leaves via hydrothermal technique. The prepared Pp-carbon nano- dots were characterized using UV-vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The Pp-carbon nano-dots are spherical in shape with an average size of 32 nm.

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