one of the promising applications of Nano silica is to promote the hydration of cement blended with fly ash, slag or other pozzolanic materials(21; 7; 22). Some authors concluded that Nano silica can improve concrete workability and strength (23; 24; 25). Also others concluded that when NS (wt.%) is mixed into the cement mortar in the fresh state it has a direct influence on the water amount required in cement mixtures, for that higher amounts of water or chemical admixtures are needed to keep the workability of the mixture (26; 27; 16). 2.2.2. Influence of Nano silica addition on cement pastes, and mortars Hui Li et al.
The pH level was frequently checked with the aid of pH indicator paper for fine coating thickness. Whenever the coating starts a drop of SDS surfactant was plunged into the Ni-P bath exactly on the coating zone. Simultaneously nano Sic was stirred well in the separate beaker using magnetic stirrer for 1 hour. Fine stirred nano Sic was injected on to the Ni-P bath using injector with uniform time interval. After coating of the first layer (nickel phosphorous) for
Results and discussion Reaction mechanism of the sol-gel process Monodisperse silica NPs can be prepared by hydrolysis and condensation of alkoxysilanes in a mixture containing alcohol, water, and catalyst. The chemical reactions describing the hydrolysis and condensation of TEOS and MTES are shown in Fig. 3. As shown in this figure, TEOS can be hydrolyzed and condensed to form SiO2 colloid particles in mixture of Methanol, NH4OH and H2O after being stirred for 1 h at room temperature. Similar to the results reported by Wang et al., the obtained inorganic silica (SiO2) colloid particles have active hydroxyl groups on their surfaces.
This process takes place in a conical or cylindrical cyclone, solutions of drug Nano suspensions produced by HPH are sprayed feed from the up to down, even hot air is applied from the same direction and spherical shape particles are obtained. Polymers, sugars or sugar alcohols like mannitol or sorbitol are water soluble matrix which are used for drug Nano suspension formulation. Atomizer is used for spraying which rotates rapidly and due to the centrifugal effect scattering to the solution takes place. Nitrogen gas or air at constant pressure are applied via outer tube. Spraying can be done by nozzle which leads to very small particles i.e.
In the one-step technique combines the production of nanoparticles and dispersion of nanoparticles in the base fluid into a single step. There are some variations of this technique. In one of the common methods, named direct evaporation one-step method, the Nano fluid is produced by the solidification of the nanoparticles, which are initially gas phase, inside the base fluid. The dispersion characteristics of Nano fluids produced with one-step techniques are better than those produced with two-step technique. The main drawback of one-step techniques is that they are not proper for mass production, which limits their
In this study, the CNT/ramie fiber hybrid multi-scale reinforcement system has been used to investigate the effect of this system on the mechanical and interfacial properties with an epoxy matrix. A simple chemical method is proposed to graft CNT on the surface of ramie fiber. The CNT has been grafted on ramie fiber by means of a silane coupling agent. The composite plates were fabricated using vacuum infusion method. The study aims to explore the CNT grafting mechanism on ramie fiber, and the effect of the hybrid reinforcement on the mechanical and interfacial properties was
A considerable narrow size distribution of nano particles was obtained at 0.001 molL-1 concentration (Fig.5), while ploydispersed nano particles were produced at higher concentration. The lower concentration process indicates diffusion limited growth process of nano particles which results in mono dispersed nano particles at lower precursor concentration. Greater rate of reaction at higher concentration of FeCl3 produced large number of metal ions. Therefore the growth process at higher precursor concentration was surface controlled in which the diffusion of growth species from the bulk to the growth surface was sufficiently rapid due to greater availability of metal ions. The mono nuclear growth mechanism of larger nano particles obtained at higher concentration was also responsible for broadening of size distribution of nano particles at 0.005 molL-1 concentration.
When the particles settle down discard the liquid portion and fill the beaker with distilled water. Again keep the magnet below the beaker and let the particles settle down and discard the liquid portion repeat this procedure till the pH becomes 7. 3. Characterization Result and Discussion 3.1 XRD of Silicon oxide It was found using XRD that the crystalline size was in nanoscale. The size of silicon oxide nanoparticles was found to be 0.04 nm respectively by using Debye-Scherrer formula .
The grafted fiber has improved swelling and thermal properties in comparison to the pristine fiber. The grafted fiber showed good affinity for both the dyes. Better swelling properties, thermal properties and affinity for dyes evinces that the grafted rayon fiber can be useful in waste water treatment applications. Cotton Gamma radiation is used to covalently link polymer chains of [2-(methacryloyloxy) ethyl] trimethylammonium chloride (maetc) to cotton fabric by mutual radiation grafting. Grafting extent increases with the dose and monomer concentration and causes antibacterial efficacy against various bacteria to increases.