Objective(s): Quince seed mucilage (QSM) serves as a new source of hydrocolloid which extracted from outer pericarp of Cydonia oblonga seeds upon wetting. It has been traditionally used for the treatment of diseases such as pharyngeal disorder, common cold, colic ulcer, and diarrhea. The aim of the present study was to evaluate the physico-mechanical and antimicrobial properties of quince seed mucilage supplemented with titanium dioxide (TiO2) and Silicon dioxide (SiO2) nanoparticles. Methods: The antimicrobial property of designated QSM against Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157: H7 was determined using agar disk diffusion and broth micro-dilution assays. Thickness, tensile strength (TS), puncture force (PF), puncture deformation (PD), swelling index (SI), and color of active QSMs were evaluated using analytical instruments. Results: The films containing TiO2 and SiO2 nanoparticles exhibited good antimicrobial effects against S. aureus, B. subtilis, B. cereus, L. monocytogenes, S. typhimurium, and E. coli O157: H7 ranged 0. 82-6. 88 mm and-2. 78--0. 28 log differences in population (DP) regarding agar disk diffusion and broth microdilution assays, respectively. The presented values, including TS, PF, and PD of QSM films, were in the ranges of 22. 45-35. 81 MPa, 10. 42-15. 49 N, and 15. 53-18. 45 mm, respectively. Conclusions: Application of TiO2 and SiO2 nanoparticles greatly improved the antimicrobial and physico-mechanical properties of the prepared films.

Background and Objectives: Heavy metals such as cadmium causing numerous adverse effects on the aqueous solutions. So the presence of heavy metals in surface water and ground water has become a major inorganic contamination problem. There are several method to remove the heavy metals from aqueous solutions that adsorption is one of the best method. The aim of this study was to evaluate the efficiency of Silicon dioxide nanoparticles modified by 2-aminopyridin and EDTA as adsorbent for the removal of Cd2+ ions from aqueous solutions. Materials and Methods: Silicon dioxide nanoparticles with toluene put in ultrasonic bath. Then mixture of 2-aminopyridin and EDTA with ratio of 1: 1 added to primary solution. After 24 hours reflux on oil bath and 10 minutes centrifuging, sample rinsed by chloroform, ethanol and deionized water. In the end, the product prepared after drying at 100 oC for 24 hours. Experiments were conducted to study the effect of solution pH, temperature, contact time, absorbent amount and initial metal concentration. Experiment conducted in bath system with three replicate. The test solutions of various concentrations were prepared from the stock solution. The solution pH was adjust using 0. 1 M HNO3 and 0. 1 M NaOH at the beginning of the experiment and not controlled afterwards. Solution containing adsorbate and adsorbent was taken in 250 mL capacity conical flask and agitated at 120 rpm in a shaker at predetermined time intervals. Samples putted on the centrifuge with 4000 rpm for 5 minutes. Lead ions were determined spectrophotometrically by atomic absorption spectrophotometer. Finally for determination of adsorption mechanism, adsorption isotherm models and kinetic models were studied. Results was analyzed by Excel software. Results: The Results showed that, the highest uptake and optimum conditions was observed in pH=4, contact time 35 minutes and temperature 25 oC. The Analysis of Langmuir isotherm (R2=0. 93) and Freundlich isotherm (R2=0. 94) show that, experimental data were fitting match by both isotherm but it is more fitting match with Freundlich isotherm. Kinetic studies showed that, kinetic of adsorption according to pseudo second order equation (R2=0. 99). Conclusion: Base on the results it can conclude that, modified Silicon dioxide nanoparticles could be used as a best adsorbent for the removal of heavy metals from aqueous solutions especially for the industrial wastewaters because of the cost, easy to use, renewable, suitable and environmental friendly. Comparing with other similar studies these were found to be the excellent adsorbents and can be successfully used by Industries for heavy metal removal.

The X-ray fluorescence spectrometry and the MA. BM. 006 reference spectrophotometric methods were used to determine the content of SiO2 (%) in bauxites from different deposits. The treatment of samples prior to the analysis involved the following steps: annealing, melting using the borax method, and the formation of beads. Certified reference bauxite samples were used for the calibration curve. The calibration curve was produced with the correlation coefficient of r =0. 9999 and the standard error of S = 0. 0246. The average residual value between the content of SiO2 determined using the XRF method, and the reference method was 0. 045, with a standard deviation of 0. 068. The XRF method was statistically verified by the F-and t-tests (using the standard sample and the reference method). The values obtained in the tests show that the XRF method yields accurate results and that there are no standard errors.

Silicon dioxide (SiO2) in nanoscale had been detected as waste product in river water for the past two decades and it is recently proven to have adverse effects toward human and animal health, the ecosystem and water treatment system. The removal of SiO2 nanoparticles (NPs) from water still remains a challenge due to its small size and unknown interactions within the water body. In this study, dynamic light scattering (DLS) technique was applied to characterize SiO2 in terms of surface charge and particle size as a function of pH within the range of 2 to 11 to analyze the aggregation behavior and significance of the intermolacular interactions in deionized (DI) water and tap water. DLS analysis identified both pH values of the point of zero charge (pHPZC) of SiO2 NPs in DI water and tap water at pH 3. 2 and pH 2. 8 respectively. The initial pH was discovered at 7. 1 in tap water with a mean particle size of 346 nm and an average surface charge value of-27 mV compared to initial pH of DI water which was 5. 4 with mean particle size of 295 nm and an average surface charge value of-33 mV. It was found that both in DI water and tap water, SiO2 NPs aggregated and increased in particle size but reduced in surface charge when pH slowly decreased towards their respective pHPZC from the initial pH by adding 0. 25M of hydrochloric acid. The mean particle size at pHPZC in DI water is measured at 1750 nm larger compared to the mean particle size in tap water indicating that the presence of other ions in tap water suppressed the aggregation process. In conclusion, results suggests that pH does influence the surface charge of SiO2 NPs and affect the stability behavior and its interaction processes in aqueous suspensions.

Objective(s): Due to nanocomposites antimicrobial properties, one of the most extensive usages of nano-products is in packing industry. Thus, the production of packages with nanotechnology can effectively prevent against a variety of microorganisms.In this study, the Silicon dioxide nanoparticles the poly (lactic acid) PLA films on antimicrobial and permeability was investigated.Methods: In order to measure the effect of antibacterial nano-covers, the direct contact of 1%, 3% and 5% Silicon dioxide nanoparticles was used. Furthermore, the sample was contaminated with standard strains of gram-negative (Escherichia coli–code of 1399 (ATCC 25992)) and bacteria gram-positive (Staphylococcus aureus–code of 1431 (ATCC 25923)) provided. Diameters of inhibition zones were measured after 24 h incubation of plates at 37 °C, by using Digital Caliper. Also, the water vapor permeability was investigated according to ASTM E96 and oxygen standards according to ASTM D 3985 standard from film surface.Results: Comparison the mean diameter of the inhibition zone of Escherichia coli, PLA containing 3% Silicon dioxide with PLA film containing 5% silica showed no significant difference between the two groups (P>0.05) as well as, the average diameter of Staphylococcusaureus (P>0.05). The results showed that the permeability compared to water vapor and oxygen vapor in pure PLA films with PLA containing 1%, 3% and 5% Silicon dioxide showed a significant difference (P<0.05).Conclusion: PLA /nanocomposite SiO2 films have been identified as the most efficient cover in reducing the microbial load and have been useful as active antimicrobial nanopackaging.

The main objectives of this study were to evaluate the biodegradation behaviour of experimental particleboard bonded with modified 30 % of PVOH, 70 % of Oil palm starch and 3 % of nano Silicon dioxide (SiO2). Boric acid at 2 % was also added as a cross-linker to PVOH in modified oil palm starch to enhance decay resistant for the samples. All the particleboards were evaluated by soil burial, borer and fungal strains tests. The samples were then compared with particleboard bonded with native oil palm starch and commercial urea formaldehyde (UF). The results indicated that particleboards bonded with modified PVOH/Oil palm starch were more resistant than particleboard bonded with their native starch and thus can be used as a potential binder for green particleboard in future. The SiO2 also showed a significant effect towards modified oil palm starch as compared to their native oil palm starch and commercial binder.

In this study، nanocomposite PES based membranes were prepared by using sulfonated Silicon dioxide (SiO2-SO3H) nanoparticles through phase inversion method. PVP and N-N-dimethylacetamide were used as pore former and solvent respectively. The effect of nanoparticles’ concentration on the separation performance of prepared membranes was studied. The structures of membranes were investigated by scanning electron microscopy (SEM) and scanning optical microscopy (SOM). Obtained results showed modified membranes had significant improvements in flux and rejection with increasing sulfonated Silicon dioxide nanoparticles. Also، the tensile strength increased in the range of 15 to 25% for prepared membranes containing naniparticles. Results showed that nanocomposite membrane containing 0. 1 wt. % SiO2-SO3H nanoparticles has an increase in the flux of 200% compared to the unmodified membrane and salt rejection of 75%. Also، the flux decreased the ratio of the optimum sample was 7. 14 that showed better antifouling properties with decreasing of 75% relative to the PES one.