scholarly journals COMPOSITES BASED ON CALCIUM PHOSPHATES AND COPPER NANOPARTICLES

2021 ◽  
pp. 320-328
Author(s):  
Ольга Николаевна Мусская ◽  
Валентина Константиновна Крутько ◽  
Анатолий Иосифович Кулак ◽  
Евгений Николаевич Крутько
Keyword(s):  
Polyethylene Glycol ◽  
Crystal Lattice ◽  
Optical Spectroscopy ◽  
Copper Nanoparticles ◽  
Colloidal Solution ◽  
Copper Ions ◽  
Calcium Phosphates ◽  
Molar Ratio ◽  
Mechanical Mixing ◽  
Polymer Stabilizers

Боргидридным методом с использованием полимерных стабилизаторов (полиэтиленгликоля, поливинилпирролидона) синтезированы наночастицы меди. Методом оптической спектроскопии установлено, что наибольшей стабильностью (до 1,5 месяца) обладают наночастицы меди, полученные при мольном соотношении Cu /полимер 1:3 - 6. Показано, что в отсутствии полимера либо при его небольшом содержании (мольное соотношение Cu /полимер 1:1) происходит агрегирование образующихся наночастиц и выпадение осадка, содержащего медь и ее оксиды (CuO, CuO). Механическим смешиванием аморфизированных фосфатов кальция (в порошковой и гелевой форме) и наночастиц меди (в виде коллоидного раствора) получен порошковый композит, содержащий фазы CaCuH(PO) и CuPOOH . Выявлено, что при совместном осаждении фосфатов кальция и наночастиц меди происходит встраивание ионов меди в кристаллическую решетку фосфатов кальция с образованием смешанных кислых и средних солей. Copper nanoparticles were synthesized by the borohydride method using polymer stabilizers (polyethylene glycol, polyvinylpyrrolidone). It was found by optical spectroscopy that copper nanoparticles obtained at a molar ratio Cu / polymer of 1: (3 - 6) have the highest stability (up to 1.5 months). It was shown that in the absence of polymer or at its low content (molar ratio Cu / polymer 1:1), the resulting nanoparticles aggregate and a precipitate forms containing copper and its oxides (CuO, CuO). By mechanical mixing of amorphized calcium phosphates (in powder and gel form) and copper nanoparticles (in the form of a colloidal solution), a powder composite containing CaCuH(PO) and CuPOOH phases was obtained. It was shown that during the coprecipitation of calcium phosphates and copper nanoparticles, copper ions are incorporated into the crystal lattice of calcium phosphates with the formation of mixed acidic and medium salts.

scholarly journals Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1694
Author(s):  
Noemi Jardón-Maximino ◽  
Gregorio Cadenas-Pliego ◽  
Carlos A. Ávila-Orta ◽  
Víctor Eduardo Comparán-Padilla ◽  
Luis E. Lugo-Uribe ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Crystallization Process ◽  
Copper Ions ◽  
Antimicrobial Property ◽  
Aminobutyric Acid ◽  
New Materials ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
And Staphylococcus Aureus ◽  
Thermal Stability Of

Copper nanoparticles (CuNPs) functionalized with polyethyleneimine (PEI) and 4-aminobutyric acid (GABA) were used to obtain composites with isotactic polypropylene (iPP). The iPP/CuNPs composites were prepared at copper concentrations of 0.25–5.0 wt % by melt mixing, no evidence of oxidation of the CuNP was observed. Furthermore, the release of copper ions from iPP/CuNPs composites in an aqueous medium was studied. The release of cupric ions was higher in the composites with 2.5 and 5.0 wt %. These composites showed excellent antibacterial activity (AA) toward Pseudomona aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The incorporation of CuNP into the iPP polymeric matrix slightly decreased the thermal stability of the composite material but improved the crystallinity and the storage modulus. This evidence suggests that CuNPs could work as nucleating agents in the iPP crystallization process. The iPP/CuNPs composites presented better AA properties compared to similar composites reported previously. This behavior indicates that the new materials have great potential to be used in various applications that can be explored in the future.

Efficient monitoring of dosimetric behaviour for copper nanoparticles through studying its optical properties

2019 ◽  
Vol 107 (6) ◽  
pp. 523-529 ◽  
Author(s):  
Mohamad Bekhit ◽  
Asmaa Sobhy ◽  
Zakaria I. Ali ◽  
Sameh M. Gafar
Keyword(s):  
Copper Nanoparticles ◽  
Metal Ion ◽  
Copper Ions ◽  
Dose Range ◽  
Ion Concentration ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
High Dose ◽  
Γ Irradiation ◽  
Γ Radiation

Abstract A novel high-dose dosimeter based on γ radiation reduction of copper ions and formation of copper metal inside polymer matrix were investigated. γ radiation induced synthesis of copper nanoparticles (CuNPs) in poly vinyl alcohol films were studied by UV-Visible Spectrophotometer, X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The optical absorption spectra showed that the Cu/PVA nanocomposite films have surface plasmon resonance (SPR) of copper nanoparticles which depending on irradiation doses. Upon γ irradiation these films turns its color from faint blue to deep reddish brown depending on metal ion concentration. The XRD pattern and FTIR spectrum confirm the formation of the CuNPs. The response of Cu/PVA nanocomposite dosimeters depends on both the irradiation doses and concentration of copper precursor. The dose range for these films was from 50 to 650 kGy, revealing its important applications for high dose dosimetry. Cu/PVA nanocomposites films exhibit good post-irradiation stability in dark and light.

scholarly journals Preparation of Carbon Aerogel Electrode for Electrosorption of Copper Ions in Aqueous Solution

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1864 ◽  
Author(s):  
Ziling Cao ◽  
Chen Zhang ◽  
Zhuoxin Yang ◽  
Qing Qin ◽  
Zhihua Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Copper Ions ◽  
Sol Gel ◽  
Copper Ion ◽  
Carbon Aerogel ◽  
Double Layers ◽  
Molar Ratio ◽  
Adsorption Effect ◽  
Control Variate

Carbon aerogel (CA) has a rich porous structure, in which micropores and mesopores provide a huge specific surface area to form electric double layers. This property can be applied to the application of capacitive deionization (CDI). The adsorption effect of CA electrode on Cu2+ in an aqueous solution was explored for solving heavy metal water pollution. The CAs were synthesized by a sol-gel process using an atmospheric drying method. The structure of CAs was characterized by scanning in an electron microscope (SEM) and nitrogen adsorption/desorption techniques. The adsorption system was built using Cu2+ solution as the simulation of heavy metal pollution solution. The control variate method was used to investigate the effect of the anion species in copper solution, the molar ratio of resorcinol to catalyst (R/C) of CA, and the applied voltage and concentration of copper ion on the adsorption results.

scholarly journals ESR and Optical Studies on the Interaction between Cu(II) and Pepsin

1978 ◽  
Vol 33 (5-6) ◽  
pp. 321-325 ◽  
Author(s):  
L. Sportelli ◽  
H. Neubacher ◽  
W. Lohmann
Keyword(s):  
Aqueous Solution ◽  
Electron Spin Resonance ◽  
Reaction Time ◽  
Conformational Change ◽  
Optical Spectroscopy ◽  
Electron Spin ◽  
Molar Ratio ◽  
Optical Studies ◽  
Spin Resonance

Abstract The interaction of Cu (II) with the protein pepsin has been investigated by means of electron spin resonance (ESR) and optical spectroscopy. Depending on the molar ratio of Cu(II) and pepsin in aqueous solution two different complexes are formed. A third complex can be detected after a reaction time of several days, attributed to a complex with a conformationally changed pepsin. The presence of inhibitors 1,2-epoxy-3-phenoxypropane (EPP) or diazoacetyl-ethylester (DAE) seems to hinder the conformational change. The structure of the three complexes is discussed.

scholarly journals Effects of pH and Ca/P molar ratio on the quantity and crystalline structure of calcium phosphates obtained from aqueous solutions

2009 ◽  
Vol 89 (3-4) ◽  
pp. 301-316 ◽  
Author(s):  
Omar Mekmene ◽  
Sophie Quillard ◽  
Thierry Rouillon ◽  
Jean-Michel Bouler ◽  
Michel Piot ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Crystalline Structure ◽  
Calcium Phosphates ◽  
Molar Ratio ◽  
Effects Of Ph

scholarly journals Synthesis of Nanocrystalline Cellulose Stabilized Copper Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Aminu Musa ◽  
Mansor B. Ahmad ◽  
Mohd Zobir Hussein ◽  
Saiman Mohd Izham ◽  
Kamyar Shameli ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Copper Nanoparticles ◽  
Metal Ion ◽  
Copper Ions ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Nanocrystalline Cellulose ◽  
Average Particle ◽  
Face Centered Cubic ◽  
X Ray

A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC) using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC) was investigated by UV-visible spectroscopy (UV-vis), where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD) analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM), which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS) also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

Characterization of Nano-Biphasic Calcium Phosphates Synthesized under Microwave Curing

2008 ◽  
Vol 3 ◽  
pp. 67-87 ◽  
Author(s):  
Wafa I. Abdel-Fattah ◽  
Fikry M. Reicha ◽  
Tarek A. Elkhooly
Keyword(s):  
Ph Value ◽  
Calcium Phosphates ◽  
Chemical Precipitation ◽  
Calcium Deficiency ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Curing ◽  
Tcp Phase ◽  
Diffraction Patterns

Two biphasic BCP ceramic samples were synthesized by chemical precipitation and microwave curing of calcium deficient hydroxyapatite CDHA under the same pH value and temperature but varied in their initial Ca/P molar ratio. Precipitates were characterization after thermogravimetric analysis, fourier transform infrared spectroscopy, X-ray diffraction, atomic absorption spectroscopy and TEM. Hydroxyapatite (HA) contents were measured for the two biphasic calcium phosphate (BCP) ceramics by sintering the calcium-deficient apatites (CDHA). The results reveal two condensation mechanisms of HPO42- affecting the Ca/P molar ratio after calcination. The X-ray diffraction patterns of BCP powders show the in situ formation of -TCP in the BCP powder. The amount of -TCP phase increases as the initial Ca/P molar ratio decreases due to more calcium deficiency in CDHA structure. The influence of HPO42- incorporation on increasing -TCP phase content after calcination is evaluated. TEM micrographs proved the effect of microwave curing during the preparation process on reducing of particle size to nanoscale range and the destruction of CDHA to finer HA and -TCP particles upon calcination.

Biosynthesis of Copper Nanoparticles Using Aqueous Extracts of Aloe vera and Geranium and Bioleaching Solutions

2017 ◽  
Vol 262 ◽  
pp. 193-196 ◽  
Author(s):  
Agnieszka Pawlowska ◽  
Zygmunt Sadowski
Keyword(s):  
Copper Nanoparticles ◽  
Room Temperature ◽  
Copper Ions ◽  
Aloe Vera ◽  
Distilled Water ◽  
Aqueous Extracts ◽  
Nanoparticles Synthesis ◽  
Leaching Solution ◽  
Chemolithotrophic Bacteria ◽  
Cut Leaves

Present work deals with synthesis of copper nanoparticles at the room temperature, using two aqueous extracts prepared from green and dry leaves of Aloe vera and Geranium (Pelargonium graveolens). Finely cut leaves were placed in the flask with the distilled water. The mixture was boiled for 15 min at the temperature of 60°C. After boiling, the mixture was centrifuged and pure extract was used for copper nanoparticles synthesis. The source of copper ions was leaching solution obtained from the bioleaching of copper shale (Kupferschiefier) using chemolithotrophic bacteria such as Acidithiobacillusfrerooxidans. The bioleaching procedure was performed in the column reactor.

Influence of the Chemical Molar Ratio on the Copper Nanoparticles: Controlled-Surfactants, -Reducing Agents, and -Precursors

2016 ◽  
Vol 37 (5) ◽  
pp. 700-704
Author(s):  
Chang-Wan Kim ◽  
Hakyung Jeong ◽  
Youngwook Noh ◽  
Dongjin Lee ◽  
Chongmu Lee ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Reducing Agents ◽  
Molar Ratio

A Study on the Preparation of PEG/FeOx Ferrofluids

2005 ◽  
Vol 475-479 ◽  
pp. 2271-2274 ◽  
Author(s):  
Shuchun Hu ◽  
Zuo Wan Zhou
Keyword(s):  
Polyethylene Glycol ◽  
Physical Adsorption ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Stirring Rate ◽  
Oxidation Reduction ◽  
Oxidation Reduction Reaction ◽  
Inorganic Components

As FeOx particles were prepared by oxidation-reduction reaction, the surfactant of polyethylene glycol (ab. PEG) was used to cover the FeOx particles, thus the PEG/FeOx ferrofluids were obtained. The morphology, structure and composition of the ferrofluids were investigated. The results show that the product is spheric in the shape, and the diameter of the product is obviously influenced by PEG content and slightly influenced by the stirring rate. When the content of PEG increases in the range of 50～350g/L, the diameter of the product decreases. However, when the content of PEG is in the range of 350～750g/L, the diameter increases with the increasing of PEG content. When the stirring rate is between 50 and 150r/min, the diameter of the product slightly decreases as the stirring rate increases. Moreover, the results demonstrate that the products are mainly constituted of PEG and FeOx, and the value of x in the formula of FeOx can be adjusted by controlling the molar ratio of H2O2 to Fe2+. Further analysis indicates that the organic and inorganic components of the PEG/FeOx ferrofluids are combined by both physical adsorption and coordinate combination.

Sign in / Sign up

Export Citation Format

Share Document