silicate
210752559
Effect of aluminum sulfate on the hydration of Portland cement, tricalcium silicate and tricalcium aluminate
Abstract Alkali free accelerator, mainly composed of aluminum sulfate (AS) is a widely used chemical admixture in the sprayed concrete. Thus, the impact of AS on the cement hydration should be further studied. This research focused on the effect of AS on the hydration reaction of C3S and C3A, illustrated by various measurements, including hydration heat, XRD, TGA, and thermodynamic modeling. Results indicated that AS accelerated the C3S hydration by rapidly generating AFt in induction period, and facilitated the C3A hydration by producing SO4 AFm and OH AFm after a short hinderance. These facilitations were integrated into the promotion on cement hydration. The findings could provide guidance for the development of accelerator.
Xiaohai Liu Baoguo Ma Hongbo Tan Benqing Gu Tong-Yi Zhang Pian Chen Hainan Li Junpeng Mei
218964317
Precipitation of silver nanoparticle within silicate glassy matrix via Nd:YAG laser for biomedical applications
Abstract: Nanosecond Nd:YAG laser technique as a unique method was adopted for the precipitating of silver nanoparticles within a bulk glass material. Soda lime silica glass of nominal composition 75SiO2.15Na2O.10CaO (mol and other samples containing 0.25, 0.50, 1.00 g per batch overweight silver nitrate were successfully synthesized via traditional melt quenching route. Synthesized samples were subjected to Nd:YAG laser irradiation. Upon laser irradiation, a noticeable shift of color was detected inside the regions of the silicate glasses which was due to the development of silver nanoparticles. XRD patterns indicate the decrease in the characteristics of two halos at about 27deg and 44deg with increasing the precipitated AgNPs content inside the silicate glassy matrix. FT IR spectra show minor changes in the fingerprint region attributed to the rearrangement of silver ion within the glassy matrix. The optical absorption spectra confirm the formation of red shift in the band position at 420 nm which have been obtained with increasing the content of silver nanoparticle precipitated in the silicate glasses. The morphological investigation according to HR TEM and FE SEM micrographs confirms silver nanoparticles precipitated in the silicate glasses after laser irradiation. Studied antibacterial activity against pathogenic grams indicates great enhancement with increasing precipitated silver nanoparticles content within the silicate glasses and suggests their suitability for different biomedical applications.
A A Menazea A M Abdelghany
210238897
Influence of sodium silicate powder silica modulus for mechanical and chemical properties of dry mix alkali activated slag mortar
Abstract Sodium silicate powders with different SiO2/Na2O (silica modulus) were characterized by solubility rate, pH, and chemical structure (by 29Si MAS NMR) and compared in the preparation of one part (or dry mix) alkali activated blast furnace slag mortar. The low SiO2/Na2O indicated the beneficial presence of less polymerized silica (Q1 and Q2 Si environments) and thus faster dissolution. Consequently, using sodium silicates with SiO2/Na2O of 0.9, 2.1, and 3.4 resulted 28 d compressive strengths of 103, 80, and 2 MPa, respectively, with increasing setting time and decreasing heat release in isothermal calorimetry. Adjustment of activator SiO2/Na2O from 2.1 or 3.4 to 0.9 by adding NaOH powder resulted increased or decreased mechanical properties of mortar, respectively, depending on the initial silica modulus. These properties were not, however, similar to those obtained with sodium silicate having SiO2/Na2O of 0.9 originally. Depending on the case, the added NaOH can be consumed for dissolving sodium silicate activator, slag, or the forming (C,N) (A) S H gel.
Tero Luukkonen Harisankar Sreenivasan Zahra Abdollahnejad Juho Yliniemi Anu M Kantola Ville-Veikko Telkki Paivo Kinnunen Mirja Illikainen
225229107
SnO reinforced silicate glasses and utilization in gamma radiation shielding applications
The influence of tin (II) oxide (SnO) on the g ray radiation protection characteristics of binary silicate glass samples with the form (100 x)SiO2 xSnO, 40 mol% x 60 mol% was investigated. T.
Yasser Rammah Karem Abdel-Azeem Mahmoud R El-Mallawany F I El-Agawany Gulfem Susoy Huseyin Ozan Tekin
85456577
Biodegradable Biomimic Copper/Manganese Silicate Nanospheres for Chemodynamic/Photodynamic Synergistic Therapy with Simultaneous Glutathione Depletion and Hypoxia Relief.
The integration of reactive oxygen species (ROS) involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) holds great promise for enhanced anticancer effects. Herein, we report biodegradable cancer cell membrane coated mesoporous copper/manganese silicate nanospheres (mCMSNs) with homotypic targeting ability to the cancer cell lines and enhanced ROS generation through singlet oxygen (1O2) production and glutathione (GSH) activated Fenton reaction, showing excellent CDT/PDT synergistic therapeutic effects. We demonstrate that mCMSNs are able to relieve the tumor hypoxia microenvironment by catalytic decomposition of endogenous H2O2 to O2 and further react with O2 to produce toxic 1O2 with a 635 nm laser irradiation. GSH triggered mCMSNs biodegradation can simultaneously generate Fenton like Cu+ and Mn2+ ions and deplete GSH for efficient hydroxyl radical *OH) production. The specific recognition and homotypic targeting ability to the cancer cells were also revealed. Notably, relieving hypoxia and GSH depletion disrupts the tumor microenvironment (TME) and cellular antioxidant defense system, achieving exceptional cancer targeting therapeutic effects in vitro and in vivo. The cancer cells growth was significantly inhibited. Moreover, the released Mn2+ can also act as an advanced contrast agent for cancer magnetic resonance imaging (MRI) Thus, together with photosensitizers, Fenton agent provider and MRI contrast effects along with the modulating of the TME allow mCMSNs to realize MRI monitored enhanced CDT/PDT synergistic therapy. It provides a paradigm to rationally design TME responsive and ROS involved therapeutic strategies based on a single polymetallic silicate nanomaterial with enhanced anticancer effects.
ACS nano
Conghui Liu Dongdong Wang Shuyuan Zhang Yaru Cheng Fan Yang Yi Xing Tailin Xu Haifeng Dong Xueji Zhang
212752194
Outcome of Root Canal Treatments Using a New Calcium Silicate Root Canal Sealer: A Non Randomized Clinical Trial
Background: The aim of this study was to compare the success rate of root canal treatments undertaken using a calcium silicate root canal sealer in combination with a single cone with non calcium silicate cement and warm vertical condensation. Methods: 150 necrotic or pulpitic teeth were treated. (REC: 08/H0804/79) Following standardized root canal chemo debridement. The canals were obturated using warm vertical condensation of gutta percha and epoxy based sealer (AH plus) or a calcium silicate sealer (BioRootTM RCS) with a single cone technique. Follow up assessment was conducted at 12 months using Cone Beam Computed Tomography (CBCT) Results: At 1 year recall, 104 teeth were assessed (51 AH plus, 53 BioRootTM RCS) The success rate using loose criteria for the CBCT images and PA radiographs was respectively 80% and 89% in the AH plus/warm vertical condensation group, 84% and 90% in the BioRootTM RCS/single cone group. There was no statistically significant difference between the two groups (Fisher exact test p value 0.6099 for the CBCT images) Conclusion: Within the limitations of this non randomized trial, a calcium silicate cement in combination with single cone resulted in a similar proportion of successful cases compared to warm vertical condensation and epoxy based sealer.
Journal of clinical medicine
Angelo Zavattini Alan Knight Federico Foschi Francesco Mannocci
224946857
Fibrillar calcium silicate hydrate seeds from hydrated tricalcium silicate lower cement demand
Abstract Debates remain on the influencing factor and long term performance of C S H seeded paste. In this study, phase pure seeds were prepared from diluted Ca3SiO5 hydration. The seed structures were determined using synchrotron based X ray diffraction, X ray absorption spectroscopy, and transmission electron microscopy. Nano foils and similar Ca and O environments were present in seeds of different Ca/Si; nanofibers were present in high Ca seeds only which showed lower silicate polymerization. Calorimetry and setting results showed a greater hydration acceleration with high Ca seeds; seed shape dominated the acceleration. 0.5 wt% high Ca seeds increased 1 and 28 days paste strength by 300% and 20% respectively. Life cycle assessment showed negligible
Cement and Concrete Research
Jiaqi Li Wenxin Zhang Ke Xu Paulo J M Monteiro
52306070
In situ grown manganese silicate from biomass derived heteroatom doped porous carbon for supercapacitors with high performance.
Supercapacitor performance is reported for manganese silicate hybridized carbon materials (MnSi C) that is derived from natural bamboo leaves. The in situ generated manganese silicate is in good distribution by a simple hydrothermal treatment without the addition of another controlling agent. We also study the performance of MnSi C as a single electrode and a cathode for fabrication of asymmetric supercapacitor device with a Ni(OH)2 anode. Remarkably, the single electrode MnSi C 3 delivered a capacity of 162.2 F g 1 at a current density of 0.5 A g 1. The cyclic performance of single electrode MnSi C 3 maintains high capacitance retention of 85% after 10,000 cycles of charge discharge. By assembled MnSi C 3 with Ni(OH)2, the asymmetric supercapacitor device shows a capacity of 438.5 mF cm 2 at a scan rate of 4 mA cm 2. The device exhibits an optimal electrochemical performance with an energy density of 3 mWh cm 3 (24.6 Wh kg 1) and power density of 130.4 mW cm 3 (604.8 W kg 1) A reasonable mechanism of in situ generated manganese silicate on the surface of carbon is proposed based on the experimental data and existed theories. This MnSi C nanocomposite proves to be a promising electrode material for high energy supercapacitor.
Journal of colloid and interface science
Qiushi Wang Yifu Zhang Hanmei Jiang Changgong Meng
197297934
Cobalt nickel silicate hydroxide on amorphous carbon derived from bamboo leaves for hybrid supercapacitors
Abstract 3D hierarchical cobalt nickel silicate hydroxide/C (CoxNi3 xSi2O5(OH)4, denoted as CoNiSi) composites are derived from bamboo leaves and explored as electrode materials for supercapacitor. The CoNiSi architectures with hierarchical petal like shapes are in situ generated on 3D amorphous carbon derived from bamboo leaves using the biomass inherent SiO2 species as the silicon source. The CoNiSi/C electrode shows a 3D hierarchical porous structure, high specific surface area and remarkable electrochemical performance with 226 F g 1 at 0.5 A g 1 in the voltage window of 0.8 0.6 V, which is superior to the specific capacitances of SiO2/C, CoSi/C, NiSi/C and even the reported values of silicates based materials. It also achieves excellent cycling performance with 99% after 10,000 cycles. Moreover, a high performance solid state hybrid supercapacitor (HSC) device is fabricated by CoNiSi/C and Ni(OH)2. This HSC device achieves an outstanding electrochemical performance with the capacitance up to 254 mF cm 2 (64 F g 1) at 2 mA cm 2, and the energy density up to 0.793 Wh m 2 (20.0 Wh kg 1) at 3.75 W m 2 (94.5 W kg 1) which are higher than a majority of former SCs based on silicates. Besides, the HSC device shows good cycle stability with 82% after 10,000 cycles and can light the red LED lasting for more than 2 min. These features demonstrate that the 3D CoNiSi/C architectures can be considered as a promising and efficient material for SCs with high performance.
Chemical Engineering Journal
Yifu Zhang Chen Wang Hanmei Jiang Qiushi Wang Jiqi Zheng Changgong Meng
104414715
Designed mesoporous hollow sphere architecture metal (Mn, Co, Ni) silicate: A potential electrode material for flexible all solid state asymmetric supercapacitor
Abstract The high performance of a supercapacitor device relies largely on the nanoarchitectures scrupulous designed and electrode material used. In this work, by utilizing Stober method prepared SiO2 sphere as a template, porous hollow spherical nanostructured metal silicates (MnSi, CoSi and NiSi) were synthesized by a hydrothermal method. When MnSi, CoSi and NiSi were used as effective positive materials for asymmetric supercapacitor, they exhibited a battery type redox behavior and a relatively high charge storage property (517.0, 452.8, 66.7 F g 1 at 0.5 A g 1) in an aqueous alkaline electrolyte. The excellent electrochemical performance is mainly based on the large surface area of metal silicates, and the porous hollow spherical structure facilitates fast electrolyte ions and electrons transportation. More importantly from the practical applications, three high capacity performance, flexible asymmetric solid state supercapacitor devices were assembled by employing metal silicates as an effective positive electrode and activated carbon as negative material in PVA KOH gel electrolyte. The MnSi//AC, CoSi//AC and NiSi//AC device showed an areal capacitance of 1048.3, 375.5 and 120.9 F cm 2, corresponding to a high energy density of 4.6, 2.6 and 0.93 mWh cm 3, respectively. The detailed formation mechanism and electrochemical mechanism of metal silicate is performed experimentally and theoretically. The results reveal that MnSi, CoSi and NiSi have a potential application in energy storage.
Chemical Engineering Journal
Qiushi Wang Yifu Zhang Hanmei Jiang Xiaojuan Li Yan Ling Cheng Changgong Meng