نتایج جستجو برای: پوسته fe3o4 sio2
تعداد نتایج: 23409 فیلتر نتایج به سال:
We present a study on the magnetic properties of naked and silica-coated Fe3O4 nanoparticles with sizes between 5 and 110 nm. Their efficiency as heating agents was assessed through specific power absorption (SPA) measurements as a function of particle size and shape. The results show a strong dependence of the SPA with the particle size, with a maximum around 30 nm, as expected for a Néel rela...
fe3o4 magnetic nanoparticles were synthesized by co-precipitation of fe2+ and fe3+ in aqueous naoh. then silica was coated on the obtained nanoparticles and the whole composite was functionalized with chlorosulfonic acid in ch2cl2. the obtained nanocomposite (fe3o4@sio2-so3h) was characterized by ft-ir, vsm and xrd techniques and was used as an efficient catalyst in condensation reaction of ind...
In this paper, we describe the synthesis and characterization of a luminomagnetic microspheres with core-shell structures (denoted as Fe3O4@ SiO2 @SiO2-Tb(PABA)3). The luminomagnetic microspheres were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM),...
<p>Photocatalytic degradation for wastewater treatment is a method that has recently attracted attention. In this research, synthesized composite of Fe3O4/SiO2/NiO with magnetic properties was used the photocatalytic methylene blue dye under UV light. Furthermore, composites were characterized using XRD, FTIR, BET surface area, SEM-EDS, VSM, and UV-DRS. The results showed saturation magne...
The photocatalytic degradation of organic compounds of olive mill wastewater (OMWW) was investigated by using core-shell-shell Fe3O4/SiO2/TiO2 nanoparticles as catalyst. The preparation of nanoparticles was performed by coating onto magnetic nanoparticles a SiO2 layer, using Stober method and TiO2 layer, using sol-gel method. The photo catalyst was characterized by dynamic light scattering (DLS...
در قسمت اول این تحقیق، نانوذرات fe3o4 به روش همرسوبی سنتز شد و به روش میکروامولسیون معکوس سیلیکا دار شد سپس کمپلکس بازشیف آهن(iii) را بر سطح بستر fe3o4@sio2 تثبیت گردید. این نانوکاتالیزور (fe3o4@sio2/fe(iii) schiff base) با تکنیک های ft-ir ,vsm ,tem ,xrd شناسایی شد. xrd نانوکاتالیزور فاز مکعبی خالص را نشان داد. ریخت شناسی کروی با اندازه ذره تقریباً nm60 با تصاویرtem تأیید شد. خاصیت پارامغناطیسی ...
In this work, an electrochemical sensor (GCE/MWCNT/Fe3O4@SiO2) based on a composite of multiwalled carbon nanotubes (MWCNT) and Fe3O4@SiO2 (MMN) nanocomposite glassy electrode (GCE) was developed for the detection tetracycline (TC). The formed promoted increased signal stability sensor, combining its individual characteristics such as high electrical conductivity large surface area. material ch...
objective(s): this paper describes coating of magnetite nanoparticles (mnps) with amorphous silica shells. materials and methods: first, magnetite (fe3o4) nps were synthesized by co-precipitation method and then treated with stabilizer molecule of trisodium citrate to enhance their dispersibility. afterwards, coating with silica was carried out via a sol-gel approach in which the electrostati...
in this research an effective and appropriate method has been developed for one-pot synthesis of new n-phenyl fulleroisoxazoline using fe3o4@sio2 nanoparticles as a green magnetically recyclable catalyst. the prepared catalytic samples were characterized by xrd, sem, ft-ir and vsm. the products have been characterized by physical and spectroscopic data such as ir, 1h nmr, 13c nmr, and ms analyses.
این رساله شامل دو بخش و 5 فصل می باشد. فصل اول به سنتز و تعیین ساختار نانوکاتالیزورهای sba-15-so3h و fe3o4@sio2@sba-15-so3h می پردازد. در فصل دوم و سوم به کاربرد این نانوکاتالیزورها در سنتز ترکیبات آلی پیریدو دی پیریمیدین ها و تترازول های استخلاف شده در موقعیت 5 پرداخته می شود. در فصل چهارم و پنجم از کارایی نوین وموثر کاتالیزور اسیدی، آبگریز و مغناطیسی fe3o4@sio2@me&et-phso3h در واکنش های آزاما...
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