APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Baihui Zhai,Shan Zhu,Qiang Tian,Na Li,Minhao Yan,Mark J. Henderson
The present study concerns the removal of thorium and uranium from aqueous solution, and particularly the effect of clay particle size and morphology on the adsorption of polynuclear actinide complexes by synthetic saponite nanoscale powders. Saponites were synthesized from a reactant mixture containing aluminum nitrate, magnesium nitrate, and either sodium silicate or sodium germanate . The saponite powders were analyzed by TEM , XRD , SAXS , N 2 -adsorption-desorption isotherms and FT-IR. Ge-saponite contained randomly stacked platelets ≈ 100 nm long and 80 nm wide, while Si-saponite showed roughly spherical agglomerates ≈ 60–80 nm in size. Small-angle X-ray scattering measurements indicated a hierarchical pore network among the plates and their agglomerates. Thorium polymers composed of fractal aggregates of branched filaments were characterized by synchrotron radiation-SAXS. The distribution coefficient ( K d mL/g) values for thorium (20 μg/mL) at pH 4 were: Ge-saponite (10 5 ) ≈ Si-saponite (10 5 ) > raw saponite (10 4 ) ≈ raw saponite (washed) (10 4 ). The K d values for uranium (20 μg/mL) at pH 5.5 were: Ge-saponite (10 3 ) ≈ raw saponite (washed) (10 3 ) ≈ Si-saponite (10 3 ) ≈ raw saponite (10 3 ). The difference in uranyl adsorption performance observed between the two nanoparticle forms of saponite was attributed to a larger pore width for Ge-saponite (3.5 nm) compared with Si-saponite (0.8 nm). The results have implications for mineral ore tailings containing thorium(IV) and, by analogy, Pu(IV) in a clay buffer environment within a geological repository for high-level nuclear waste .
研究领域:
环境科学
·
放射化学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Dinghui Chen,Dawei Luo,Weijun Zhen,Ling Zhao
In the work, organic saponite (OSAP) was modified with dioctadecyl dimethyl ammonium chloride and saponite by intercalation reaction. Moreover, functionalized OSAP (FOSAP) was prepared with OSAP, BASF chain extender Joncryl ® ADR 4468 and p -phenylenediamine. The optimum reaction conditions of FOSAP were optimized by orthogonal experiment. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) results demonstrated that saponite had been successfully modified. Moreover, FOSAP/poly (lactic acid) (PLA) nanocomposites were prepared by melting intercalation with PLA and FOSAP. The mechanical properties, rheological behavior and crystallization properties of FOSAP/PLA nanocomposites were investigated. Mechanical properties showed that the impact strength and elongation at break of FOSAP/PLA nanocomposites reached 13.21 KJ/m 2 and 71.47%, respectively, when the amount of FOSAP in PLA was 0.3 wt%. In addition, the Cole-Cole curve showed that FOSAP had strong interfacial compatibility with PLA. Furthermore, the crystallization behaviors of PLA before and after modification during isothermal crystallization at 150 °C were investigated by Rheonaut technology for simultaneous rheology and FTIR, which demonstrated that FOSAP effectively promoted the crystallization of PLA and increased the storage modulus . Avrami equation showed that FOSAP changed the nucleation growing mode and significantly accelerated the crystallization rate of PLA, therefore the comprehensive performance of PLA was improved.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 14
·6539-6545
·
IF 11.301
Jian Zhang,Qing Yin,Jianeng Luo,Jingbin Han,Lirong Zheng,Min Wei
NiFe saponite (NF-SAP) with Na+ pillaring was investigated for the first time, as a new anode material for high-performance lithium-ion batteries (LIBs). In this material, non-metallic element Si and metallic elements Fe and Ni all act as active components (providing capacity) and undergo valence state changes during electrochemical progress. Si changes between Si2+ and Si4+, while Fe and Ni transform between a nearly metallic state and Fex+ and Niy+ (0 < x < 3, 0 < y < 2). In the fully lithiated state, Ni–Ni bonds appear but only Fe–O bonds can be observed in NF-SAP. The NF-SAP/Li half cell delivers a gradually increasing specific capacity in the initial hundreds of cycles (maximum capacity of 815 mA h g−1 at the 350th cycle) and maintains a capacity of 646 mA h g−1 after 1000 cycles at 500 mA g−1. The pre-pillaring effect of Na+ is responsible for the good Li+ storage performance, which leads to the decrease of Li+ transport hindrance and high contribution of pseudocapacitance. Furthermore, a full cell of LiMn2O4/NF-SAP was assembled, which shows an initial specific capacity of 104 mA h g−1 at 100 mA g−1 and maintains a capacity of 68% after 50 cycles, demonstrating the bright application prospects of NF-SAP as a promising anode material. This work shows a new kind of anode for LIBs and provides an in-depth understanding of its energy-storage mechanism. Considering the easy preparation, low cost and environment-friendly characteristics of NF-SAP, this kind of material is applicable to large-scale energy storage.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Jian Zhang,Qing Yin,Yunjia Wu,Shuoxiao Zhang,Kai-Jie Wang,Jingbin Han
A kind of layered Li 2 MSiO 4 material, Fe saponite with Na + pillaring (Na + -FSAP) was developed as a low-cost and environment-friendly lithium-ion storage material. The Na + -FSAP follows the insertion/deinsertion working mechanism accompanied by valence change of Fe from Fe 1.86+ to Fe 2.71+ (average value) after stabilization, and displays a specific capacity of 125 mAh g −1 at 50 mA g −1 with retention ratio of 80.8% after 75 cycles. The Na + -pillaring effect and abundant structural water in the gallery urge Li + migrate rapidly, resulting in a large Li + diffusion coefficient within a range of 10 −6.5 –10 −7.5 cm 2 s −1 . Thus, the Na + -FSAP provides a model material to design electrode materials with rapid lithium-ion migration and has great potential to take place of polyanionic-type Li 2 MSiO 4 (M = Mn, Fe, Co) cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2018
·
IF 3.641
Qi Tao,Manyou Chen,Hongping He,Sridhar Komarneni
Mixed metal oxides (MMO) were transformed to phyllosilicate in the presence of silicate anions under hydrothermal conditions. The product was shown to be saponite with a trioctahedral layer structure by characterization with XRD , FTIR , 27 Al and 29 Si MAS NMR, HRTEM and TG-DTG. The formation of saponite was through a rehydration-dissolution-precipitation pathway, involving the critical steps such as the reconstruction of MMO to hydrotalcite (Ht), exsolution of Al 3+ from Ht, condensation of metasilicate anions with Ht, and finally crystallization of saponite. Isomorphous substitution of Al 3+ for Si 4+ in silicate oligomers is the key for the above conversion, which generated the negative charge necessary for the condensation between the silicate oligomers and Ht surface and the formation of 2:1 saponite TOT layers. High pH value (over 14.0) favored the condensation of silicate oligomers and led to crystallization of saponite. Thus, we report a novel method for the crystallization of saponite.
研究领域:
矿物学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymer-Plastics Technology and Materials
·
2022
·
IF 2.439
Hao Li,Yikelamu Jilili,Weijun Zhen,Ling Zhao
Saponite (SA)-mercaptopropyl polyhedral oligomeric silsesquioxane (POSS-SH) grafted poly (L-lactic acid) (SA-POSS-PLLA) was synthesized by thiol-ene click chemistry. SA-POSS-PLLA was characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. When 0.3 wt% SA-POSS-PLLA was used as a modifier in poly (lactic acid) (PLA), the impact strength and elongation at break of PLA/SA-POSS-PLLA nanocomposites were increased by 1.73 times and 4.25 times compared with pure PLA, respectively. The differential scanning calorimeter analysis showed that the crystallinity of PLA/SA-POSS-PLLA nanocomposites was increased from 7.74% to 30.32%. The addition of SA-POSS-PLLA increased the crystallization rate of PLA and significantly reduced the grain size of PLA, which also was proved by polarization optical microscopy analysis. Rheonaut technology for simultaneous rheometry and FTIR demonstrated that the reason why the addition of SA-POSS-PLLA nanoparticles accelerated the crystallization rate of PLA was that SA-POSS-PLLA nanoparticles promoted the adjustment of C-O-C structure and -CH3 group in the main molecular chain of PLA.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESOURCES RESEARCH
·
2020
·Vol. 56
·期 11
·e2019WR027037
·
IF 4.309
Tao Wu,Yuankai Yang,Zhifen Wang,Qiang Shen,Yanhua Tong,Moran Wang
Accurate understanding of diffusion of anionic radionuclides in different clays is significant to predict long-term performance of high-level radioactive waste (HLW) repositories. The importance of electrical double layer (EDL) on anionic tracer diffusion in different clays has been studied by both through-diffusion experiments and pore-scale simulations in this work. The through-diffusion experiments measured the effective diffusion coefficient and the accessible porosity of Re (VII) in compacted montmorillonite, Na-bentonite, and illite/smectite mixed layer (I/S) at different salinities. The results showed that the accessible porosity and the effective diffusion coefficient of Re (VII) in montmorillonite and Na-bentonite were similar but lower than those in I/S under the same conditions. For mechanism analysis and predictions, a pore-scale modeling was implemented to simulate the diffusion of anions in compacted clays. In the simulations, the characteristics (porosity, density, and total surface area) of microstructures of montmorillonite and I/S were used to regenerate three-dimensional pore structures numerically by a Quartet Structure Generation Set method. The Re (VII) diffusion was then simulated by directly solving coupled Poisson-Nernst-Planck equations via the lattice Boltzmann method. The diminished effect of EDL was therefore calculated and compared with Donnan and multiporosity models. As EDLs overlap in compacted clays, the Donnan model overestimates the influence of EDL on Re (VII) diffusion, while the multiporosity model underestimates it. The pore-scale modeling, which captures the structure of overlapping EDLs automatically, can simulate the diffusion of anionic radionuclides in compacted clays without any fitting parameters. Key Points A method to link through-diffusion experiments and a pore-scale modeling Prediction of Re (VII) diffusion in montmorillonite, Na-bentonite, and illite/smectite mixed layer Effect of the electrical double layer on Re (VII) diffusion in illite/smectite mixed layer decreases compared with that in montmorillonite
研究领域:
地质学
·
环境科学
✓ 已验证
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2024
·
IF 3.2
Qiang Luo,Fei Li,Weijun Zhen,Qing Ge,Yushen Zhou,Chunmei Ma,Pengtao Sun,Jianbo Xu,Buning Chen
To improve the adsorption and reusability of polypropylene (PP) fiber membranes, the organically modified saponite (Sap@P(St-co-MMA)) was prepared by solution polymerization. Furthermore, PP-based nanocomposite fiber membranes with strong oil adsorption, thermal stability, and reusability were prepared via melt-blown technology. The increased specific surface area of PP-based nanocomposite fiber membranes (PP-1.5%) provided more active sites for the oil adsorption. Simultaneous rheology and Fourier transform infrared measurements tests showed that Sap@P(St-co-MMA) enhanced the crystallinity of PP matrix, promoted the regular arrangement of molecules, and improved the intermolecular interaction force, which was beneficial for the oil adsorption. The adsorption of PP-1.5% (1.5 wt% addition of Sap@P(St-co-MMA)) fiber membrane for xylene and kerosene reached a maximum of 15.84 and 22.84 g g −1 , respectively. In the treatment of coal tar wastewater, the removal rate of oil can reach 62.9%, and the removal rate can still reach 51.17% after five cycles of experiments. In summary, PP-1.5% fiber membrane does not produce secondary pollution to the environment, and is a kind of oil removal material with good application prospect. Highlights PP-based nanocomposites fiber membrane with strong oil adsorption was prepared. Organically modified saponite had strong heterogenous nucleation for PP matrix. Sap@P(St-co-MMA) increased the specific surface area of PP-based fiber membrane.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Petroleum Science
·
2025
·
IF 6.1
Li-Yao Dai,Jin-Sheng Sun,Kai-He Lv,Ying-Rui Bai,Bo Liao,Dong-Qing Yang,Chao-Zheng Liu,Mei-Chun Li
Fractures in geological formations, which are commonly encountered during oil and gas exploration, pose significant challenges by facilitating fluid loss and reducing wellbore stability. Polymer gels hold significant promise as lost circulation materials due to their excellent deformability under pressure and self-adaptability. However, conventional gels face certain limitations, such as poor retention of gel-forming suspensions in fractures, low structural strength, and instability at high temperatures. These issues result in low pressure-bearing capacity and, consequently, reduced effectiveness in sealing formation fractures. This study presents the synthesis of a supramolecular polymer gel (SPG) composed of acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), divinylbenzene (DVB), polyvinyl alcohol (PVA), TEMPO-oxidized cellulose nanofibers (CNFs), and laponite via in situ radical polymerization. Due to the synergistic effects of hydrogen bonding and electrostatic interactions, the supramolecular polymer gel-forming suspension exhibits high retention capacity in fractures. The as-synthesized gels demonstrate remarkable temperature resistance and high mechanical strength, attributed to covalent bonding, multiple hydrogen bonding, and electrostatic interactions, along with the high aspect ratio and modulus of CNFs and laponite. This study broadens the application scope of CNFs, laponite, and SPGs, offering a novel approach for the efficient development of unconventional oil and gas resources.
研究领域:
材料科学
·
石油工程
·
高分子化学
·
纳米复合材料
·
油田化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Minmin Chen,Linlin Li,Wei Ji,Wensheng Lu,Xiaochao Tang,Suwei Jiang,Hualin Wang
Petroleum-based food packaging causes substantial environmental damage through waste accumulation and microplastic pollution. Therefore, replacing it with biodegradable polymers to extend the shelf life of food products is highly desirable. In this work, a bilayer functional composite with barrier properties and antimicrobial activity was developed for pork preservation. The outer barrier layer of gelatin/laponite (Ge/La) was fabricated by the casting method, while the inner antimicrobial layer of zein/eugenol (ZN/Eu) was prepared through direct electrospinning on Ge/La. The incorporation of La enhanced the thermal stability, mechanical strength, and moisture barrier of the outer layer, while the encapsulation of Eu endowed the inner layer with excellent antioxidant and antimicrobial activities. Furthermore, the Eu release from ZN/Eu fibers was found to follow Fickian diffusion. The bilayer composite of Ge/La@ZN/Eu can prolong pork shelf life by 1 d at 25 °C, demonstrating its great potential in active food packaging
研究领域:
食品科学
·
高分子科学
·
材料工程
·
食品包装技术
·
可降解材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）