Materials Used. For silver nanoparticle synthesis, silver acetate (AgAc-166.91g/mol) was procured from Sigma Aldrich and oleylamine from. Thiol terminated polystyrene (PS-SH) Mn-1100, Mw-1230, PDI-1.12 was procured from Polymer Source Inc. Canada. The polymer for micelles Polystyrene-b-4vinylpyridine (PS-b-4VP) Mn(PS)=18,500; Mn(P4VP)=40,500; PDI-1.10 was procured from Polymer Source Inc. Canada. The Si sol precursor tetra ethyl orthosilicate (TEOS) was procured from Sigma Aldrich. Sodium borohydride and p-nitrophenol was procured from Sigma Aldrich (99.9%) and Across Organics (95%) respectively. Organic solvents including Toluene and Methanol were procured from Acros Organics and Chloroform from Fischer chemicals and Ethanol from VWR PROLABO was of analytical grade and used as received. Millipore water (18.2 ohm cm at 25 degree C, cleaned with Pure Lab Plus ® ultra purification system) was used as solvent throughout the experiment and used as received. Synthesis of Polystyrene Capped Silver Nanoparticles. Silver nanoparticles were synthesised using a simple method described by Hiramatsu [Hir01]. For the …show more content…
10mg of PS-SH was dissolved in chloroform in 1:1 proportion with the nanoparticles and added to silver nanoparticle/chloroform dispersion drop by drop under stirring. 5ml more chloroform was added to the AgNP/PS mixture and was stirred for 24hours. Thereafter Ag/PS mixture was reprecipitated in 10ml of Methanol and centrifuged at 13500 RPM for 10 minutes. To remove the rest of OlAm and excess of PS-SH, repeated (6-8 times) centrifugation/redispersion steps were performed by adding chloroform as a solvent (ca. 5 ml) and methanol as flocculating agent (ca. 10 ml for each step). Final product was collected and dried under argon to give a fine metallic powder of ca. 11mg
"Silver Chloride (AgCl) - Properties and Applications." Silver Chloride (AgCl) - Properties and Applications. The A to Z of Materials, 2013. Web. 18 Feb 2014. <http://www.azom.com/article.aspx?Articl
We got 0.583g as our theoretical yield of silver nitrate, but due to our clumsiness, we scoped out about 0.593 g of silver nitrate. Compared the amount of silver nitrate that we have and the amount that we needed, Silver nitrate ( AgNo3) is our excess reactant and copper is our limiting reactant, which we will using it to find out our theoretical yield of how much silver that we should have make. There is one thing I wanted to mention that we use distilled water instead of tap water because in tap water, it contain other compound such as mineral, or Calcium, etc. Therefore, we do not want any of those to be reacted with our solution and silver, we want to produce pure silver. Next step is we placed the copper metal inside the silver nitrate solution, the color started to change into light aqua blue.
Synthesis of OA-Ag NPs: For the preparation of OA-stabilized Ag NPs [39], silver trifluoroacetate (0.4 g), OA (3.5 mL), and isoamyl ether (30 mL) were mixed in a 250 mL three-neck flask under argon. The mixture was heated at 160 °C for 30 min then cooled to room temperature by removing the heat source. The purification process was performed four times using excess polar solvent (ethanol) and centrifugation. The precipitated OA-Ag NPs were dispersed in
The surface of MBNs can be modified with the monomer as follows, first 1 mL of aqueous MBNs solution and 3 mL of 30 mg monomer in THF were mixed, and the reaction mixture was reacted at room temperature for overnight under constant stirring. We extracted the upper layer solution of the reaction mixture and extracted compound named as TF-MBNs. The same method was used for the surface Modification of MBNs with polymer (PTF-MBNs). A schematic representation of Surface modification of hybrid multi–block nanorods with thiol-terminated monomer (TF-MBNs) and polymer (PTF-MBNs) was shown in Scheme
CdSe/CdS core/shell nanocrystals were prepared by organometallic method [26] using Cadmium oxide (CdO 98.9%) was provided by Fluka. Sulfur powder (S 99.5%), Selenium powder (Se 99%), Trioctylphosphine oxide (TOPO 97%), Trioctylphosphine (TOP 90%) Hexadecylamine (HDA 97%) were purchased from Aldrich. Stearic acid 98%, Acetone 98%, Oleic acid (OA) 98%, Methanol 99%, Toluene 99% were from united chemical Lab. All chemicals and solvents had been used as received while not more purification. In the experiment, OA was used as the ligand of and TOP was used as the ligand of the Se precursor.
2-methyle pentane 99.9%, acetone, hydrochloric acid and 1-propanol 99.9% were bought from Fisher Scientific Company. Bi2O3 99%, SnCl2 99%, Na2S 99.5% , Na2SO4 99.9%, methylene blue 99.9%, and sodium lauryl sulphate 99.9% were purchased from Aldrich-Sigma. The composition of nanoemulsion was 41.67% water, 41.67% oil phase (2-methyle pentane and 1-propanol) and 16.66% surfactant. Bi3+ and Sn2+ ions were dissolved in water phase. Similarly, in separated nanoemulsion, S-2 ions were dissolved in water. All components of the nanoemulsion were blended to form a single optically isotropic mixture under stirring at room temperature of 20 oC. Nanoemulsion of Bi3+ and Sn2+ ions was added to nanoemulsion of S-2 ions and stirred for 2 hours to form
The antibacterial activities of silver and silver nanoparticles are having various important applications in biomedical field especially in topical ointments to prevent open wound and burns infection.(Duran etal 2005).The antibacterial properties of silve rnanoparticles are also extensively used for wound dressings for diabetic wounds and traumatic injuries and also to prevent bacterial colonization in prostheses and to reduce infections in surgically implanted catheters. AgNPs are also used
Scheme – 9: Shimizu et al. studied benzylation of arenes catalyzed by Ag(I) oxide, Ag(I) ion, bulk silver metal, and silica supported silver nanoparticles. Ag powder, silver oxide, Ag(I) ion and silica alone are not active towards benzylation of anisole. However, the catalytic activity of SiO2 supported silver catalysts was increased with the silver loading up to 5 wt% and decreased with further increase in the loading. Catalyst with 5 wt% Ag loading on SiO2 showed benzylated product yield about 82%. The catalyst is recoverable and reusable.25
Gold(III) chloride solution and sodium citrate solution were freshly prepared with deionized water and filtered through a syringe filter (0.22 µm). Deionized water (45 mL) was added into three-neck flask incubated in the heating mantle with a stirring bar followed by the addition of HAuCl4 solution (5 mL, 10 mM). After the solution was boiling, the sodium citrate solution (5 mL, 38.8 mM) was added quickly. The color of the mixture gradually changed from black to wine red in the first two minutes, indicating the formation of gold nanoparticles. The AuNPs solution was kept boiling for another 10 minutes with a stirring speed of 700 rpm. After cooling down the solution to room temperature, the AuNP solution was filtered through a syringe filter (0.22µm). The concentration of AuNPs was determined by UV-Vis spectrometer (Cary100,
The conclusion of the paper restated the benefits of the usage of gold nanoparticles, citing its flexibility of usage, and reviewed the discoveries of the experiments. It was discovered that benign cells need more than twice as much light intensity to be killed than malignant cells. Finally, it discusses how the procedure would need to be altered to be used in vivo. Since a wavelength between 650 and 900 nm would be required to penetrate even a few centimeters of tissue, the next step in research is altering the pure gold nanoparticles in order to maximize absorption. The
It has an attractive shiny appearance, although it discolours easily. Silver (Ag), chemical element, a white shiny metal valued for its attractive beauty and electrical conductivity. Silver is period 5 of the periodic table, between copper and gold, and its physical and chemical properties are halfway between those two metals. It is used for jewellery, mirrors, coins and silver tableware, where appearance is important. Mirrors are almost always if not always made with silver, as researchers have proved that it is the best reflector of visible light. As a result of the continually growing demand for the precious white metal is a big indicator for the future price to increase dramatically. One of many developing fields is silver nanoparticles of technology, that is producing demand for silver that is still not yet fully priced into our current market. Silver is the most important valuable metal after gold and in fact silver has no equal. Which brings us to our next topic, when it comes to conducting electricity and/or heat, silver is the only way to go. As we previously stated before, it is the best and most efficient reflector of light. Silver is widely considered as the primary choice for growing range of technologies, due to its characteristics such as its antimicrobial properties (antimicrobial is an agent that kills microorganisms or stops their growth) (En.wikipedia.org, 2018). The first mass-market use of silver was photography aside from money and jewellery. Technology utilities the conductivity of silver and has made a huge demand in the manufacture of solar energy panels. One of the newest science fields are also creating potentially significant demand for silver along with the technology utilities. A nanoparticle is a submicroscopic size unit, measuring between 1-100 nanometres. Silver nanoparticles have numerous uses in medicine and technology. Silver is one of the most
Emergence of multiple drug resistant pathogens is a major concern for clinician’s worldwide. Limitations in discovery of new antibiotics and development of drug resistant microbes necessitates the search for new antimicrobial agents which can control the spread of drug resistant pathogens. Generally third generation antibiotics control most of the pathogenic microorganisms at low doses but fail to control the multiplication of multiple drug resistant (MDR) strains at those doses and require higher doses, which leads to generation of more MDR strains and is detrimental for the environment also.Green synthesis of nanoparticles coupled with third generation antibiotics can act as an ideal agent for the control of drug resistant pathogens. Present study exploits the synthesis of silver nanoparticles by using lemon grass (Cymbopogon citratus) extract. Lemon grass extract was used to reduce silver nitrate in to nanoparticles with in 18h. SEM and FTIR Characterized nanoparticles were further applied for the control of MDR strain of E. coli growth in combination with gentamicin. It was found that gentamicin alone could not control the multiplication of MDR strain at 12.5, 6.25 and 3.12 µg/ml and lower concentrations as compared to gentamicin coupled with silver nanoparticles at a concentration of 3.125 µg/ml.
Bacteria have long since existed alongside humans, and while some are not harmful, there are many that are. Plants are commonly used natural remedies for diseases, and have been known to retain immense antibacterial properties that can fight bacteria. Silver nanoparticles have been also known to possess antimicrobial properties that aid in the fight against various bacteria. The use of plants as well as silver nanoparticles to fight against bacteria has caused much interest in the nanotechnology and medicine fields, and has been the basis of many studies. The purpose of this paper is to scrutinize the antimicrobial potency of silver nanoparticles, and how they may be utilized to fight against various harmful bacteria.
Repeat the steps again for the measurements of 3 cm3 but use 60mL of NaOH, and for the 5 cm3 the students must use 80 mL of the NaOH.
Ag ions can also interference with DNA replication processes by interact with phosphorus group, which stops bacterial proliferation and decreases the number of cells over time (Wong and Liu, 2010) and (Cao et al., 2010). Moreover, Samberg et al., 2011 proposed that the antibacterial activity of Ag ions is caused by the synergistic effect between the binding of silver ions to the cell wall, their uptake and subsequent accumulation in the cell, and their interference with critical biomolecules within the cell.