Bài giảng Hóa đại cương - Chương 2: Liên kết hóa học và cấu tạo phân tửCấu hình e hóa trị 3s của Na: Miền hóa trị chỉ có IN e nên nó chỉ mới được điền đầy một nửa. Một nửa miền còn lại tự do và đóng vai trò miền dẫn. Khi kích thích nhẹ, ví dụ tác dụng lên kim loại một điện trường, các e hóa trị dễ dàng chuyển lên những orbital còn tự do theo hướng của điện trường, thể hiện tính dẫn điện.
89 trang | Chia sẻ: yendt2356 | Ngày: 28/11/2020 | Lượt xem: 930 | Lượt tải: 0
Synthesis of nanosilica from rice husk and optimization of the removal of crystal violet dye from aqueous solution - Nguyen Van Hung4. CONCLUSIONS This paper reports our first results on the synthesis of nanosilica from rice husk. The nanosilica is an effective adsorbent for the removal of CV dye from aqueous solutions and theSynthesis of nanosilica from rice husk and optimization of the removal of crystal violet dye best removal yields were investigated with contact time...
8 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 637 | Lượt tải: 0
A study of red-Emitting phosphor of K2SiF6:Mn4+ for warm white leds - Nguyen Le Anh4. CONCLUSION In summary, we have reported the first of out attempt to creation of the Mn4+-doped K2SiF6 phosphor by one step co-precipitation process. Concequently, pure phase of cubic K2SiF6 is achieved. K2SiF6 doped 5 % content of Mn4+ shows the strong emission in red light spectrum corresponding to the 609, 614, 631, 635 and 647 nm emission...
6 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 651 | Lượt tải: 0
Magnetic resonance imaging (MRI) application of Fe3O4 based ferrofluid synthesized by thermal decomposition using poly (maleic anhydride -Alt-1- Octadecene) (pmao) - Le The Tam4. CONCLUSION In this work, high-quality magnetic fluid was synthesized by thermal decomposition with using poly (maleic anhydride -alt-1-octadecene) (PMAO) as phase transfer ligand. The additional organic coating layer has improved the stability of magnetic particles in aqueous solutions. The average diameter of the coated particles was 16.1 ±...
9 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 724 | Lượt tải: 0
Preparation of magnetic hydrogel by in-Situ coprecipitation process - Ngoc Uyen Nguyen Thai4. CONCLUSIONS We synthesized magnetic hydrogel by the in-situ co-precipitation method. Two in-situ coprecipitations were performed. The process that involved the initial formation of calcium alginate hydrogel before incorporation with iron ion and co-precipitation to afford in-situ magnetic nanoparticles in alginate hydrogel showed the most eff...
7 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 636 | Lượt tải: 0
Study of the effects of gympsum, pozzolanic additive mixtures and their fineness on the strength of PCB50 fico cement - Hoang Canh Nguyen4. CONCLUSION Pozzolanic additive has reduced the compresive strength of cement when mixed separately. However, when pozzolanic additive is mixed with gypsum additive, this additive mixture has increased the compresive strength of the cement at the late time (at the age of 28 days, the compresive strength of sample TP22 was 55.4 MPa; sample P22...
7 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 586 | Lượt tải: 0
Magnetic adsorbents based on the composite of expanded graphite and NiFe2O4 for removal of heavy oils - Pham Van Thinh4. CONCLUSIONS In brief, this study presents the fabrication, characterization of the magnetic NiFe2O4 decorated EG and its excellent performance in adsorptive sequestration of diesel oil (DO) and crude oil (CO) from aqueous solution. The maximum adsorption capacity for DO and CO was found to be about 30.2 g DO and 25.8 g CO per 1 g of adsorben...
7 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 666 | Lượt tải: 0
Graphene quantum dots as a reducing reagent and stabilizer for green synthesis of silver nanoparticles: Towards a hydrogen peroxide and glucose sensor - Tran Vinh Hoang4. CONCLUSIONS In summary, AgNPs have been successfully prepared by using GQDs as reducing agent and stabilizer. AgNPs/GQDs hybrid exhibits good performance for colorimetric detection of H2O2 and glucose. The simple fabrication procedure, effective discrimination ability, and low detection limit suggest that the proposed strategy may hold pract...
6 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 647 | Lượt tải: 0
Chitosan-Templated lightweight spinel CoAl2O4 Nanofibril aerogels - Chau The Lieu Trang4. CONCLUSION We have shown for the first time the liquid templating of lightweight CoAl2O4 nanostructured aerogels by chitosan fibrils. A new phenomenon of swelling chitosan nanofibrils in Al3+-contained water was exploited to obtain a neutral aluminum-chitosan aqueous solutions. Our interesting finding is that the lyophilization of the cobalt...
11 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 607 | Lượt tải: 0
Tailoring the structure and morphology of WO3 nanostructures by hydrothermal method - Luu Thi Lan Anh4. CONCLUSIONS We have successfully synthesized WO3 nanostructures with three different morphologies: nanoplate, nanoparticle and nanorod by hydrothermal and acid precipitation methods without using any structure-directing agent. The crystal of WO3 nanostructures transformed from orthorhombic, monoclinic to hexagonal corresponding with the chan...
8 trang | Chia sẻ: thucuc2301 | Ngày: 28/11/2020 | Lượt xem: 684 | Lượt tải: 0
