COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Guifang Wang,Jiangqi Wei,Guangchuan Liang,Yanli Chen,Shaojian Ma,Jinliang Zhu,Haiyan Liu
Montmorillonite (Mt) is widely used in various fields due to its abundant resources and excellent adsorption performance, while the hydration and adsorption properties of raw or functionalized Mt are affected by its intrinsic property, layer charge density (LCD). Herein, a series of reduced-charge montmorillonites (RC-Mt) with high, medium, and low layer charges were prepared by the method of lithiation and microwaving Ca-Mt. Meanwhile, the effects of artificially regulated layer charge density on Mt’s structure, hydration properties, and the removal ability of aqueous anions by the poly (diallyl dimethylammonium chloride) functionalized Mt (PDDA-Mt) were also investigated. Results showed that the LCD of Mt decreased with the increasing microwave time or power. In addition, the physicochemical properties of RC-Mt which included cation exchange capacity (CEC), colloidal index, and swelling properties decreased as the LCD decreased. Furthermore, the adsorption capacity of Mt for NO 3 - was significantly improved following the PDDA functionalization. The kinetic modeling suggests that the Pseudo-first-order model better characterized the adsorption of Ca-Mt and Li-Mt than the Pseudo-second-order model. On the other hand, the good fit of the Pseudo-second-order model implied that the adsorption process of nitrate on RC-Mt and PDDA-Mt is mainly driven by chemisorption control. The adsorption thermodynamics indicated that the adsorption process was spontaneous. Furthermore, the FTIR and XPS results suggested that in addition to diffusion and electrostatic interactions, the adsorption mechanism of PDDA-Mt was mainly attributed to the ion exchange between chloride and nitrate on the quaternary ammonium group of PDDA.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Petroleum Science
·
2023
·
IF 5.6
Fan Ding,Xin Jin,Tao Shen,Shan-Shan Mao,Qing Zhao,Mang-Lai Gao
Wettability is an important surface property that deserves to further explore the factors on its alteration. Series of bis -N-heterocyclic quaternary ammonium salts with different spacer length and N-heterocyclic headgroups (morpholinium (BMMB, BMMD and BMMH), piperidinium (BPMH) and piperazinium (BMPMH)) have been synthesized and employed for altering the wettability of vermiculite and its derivates (Vts) treated by Li + -saturated heating method. The results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG-DTG), scanning electron microscopy (SEM) and N 2 adsorption/desorption isotherms indicate that all of the bis -N-heterocyclic quaternary ammonium salts have been successfully inserted into the vermiculite layers, leading to the organic monolayer. The results of capillary rise tests combined with Lipophilic to Hydrophilic Ratio ( LHR ) values unveil the wettability alteration of the organo-Vts. As the layer charge decreases, the hydrophilicity of the organo-Vts gradually increases, which is probably caused by the decline in binding sites. As the result of the change in spacer length of modifier, the wetting properties of morpholinium-based organo-Vts change in order of BMMD-Vts > BMMH-Vts > BMMB-Vts, and difference in N-heterocyclic headgroups leads to the sequence of wettability: BMPMH-Vts > BPMH-Vts > BMMH-Vts. Layer charge of Vt, spacer length and the type of the N-heterocyclic headgroup of modifier have the synergistic effect on the regulation of the wettability.
研究领域:
材料科学
·
表面化学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Qiuzhi He,Runliang Zhu,Qingze Chen,Yanping Zhu,Yixuan Yang,Jing Du,Jianxi Zhu,Hongping He
Layer charge is a critical factor determining the structural characteristics and physicochemical properties of clay minerals, and fixing small cations (e.g., Li + ) into the tetrahedral/octahedral sheets of clay minerals is a feasible way for reducing their layer charges. However, conventional methods for preparing reduced-charge clay minerals are usually quite complex and time-consuming. Herein, a facile one-pot treatment method for preparing reduced-charge clay minerals was successfully developed using molten salts . In particular, montmorillonite (Mt) was mixed with mono LiNO 3 or LiNO 3 -NaNO 3 mixture, which was then heated above the melting points of salts. The obtained results showed that the cation exchange capacity (CEC) of Mt decreased evidently after being treated with molten LiNO 3 , and the CEC value was reversely related to the heating time. The X-ray diffraction results demonstrated that Mt layers collapsed upon treatment with molten LiNO 3 . On the other hand, the partial replacement of LiNO 3 by NaNO 3 could restrict the collapse of Mt layers, as the larger ionic radius of Na + (than Li + ) helped in maintaining the interlayer spaces of Mt during the process of charge reduction. As indicated by the Fourier transform infrared spectroscopy, the structural OH stretching vibration shifted to a higher wavenumber (from 3623 to 3632 cm −1 ) after the molten LiNO 3 treatment, which suggested that some Li + ions migrated into the hexagonal cavities in the tetrahedral sheets of Mt, and the new band at 3670 cm −1 indicated that some Li + ions even further migrated into the octahedral vacancies of Mt. The locations of fixed Li + ions were further confirmed by the X-ray photoelectron spectroscopy characterization. Due to the migration of Li + ions into the layers of Mt, the Li1s peak shifted to lower binding energy. The above results showed that the molten salt treatment might be a cost-effective and environmentally friendly approach for synthesizing reduced-charge clay minerals, and using mixed molten salts can help in maintaining the interlayer structure.
研究领域:
矿物学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jia-Shuai Chen,Jing Wang,Ji-Hong Zhang,Zhi-Yuan Guo,Pan-Pan Zhang,Xiao-Fu Guo,Jie Liu,Zhi-Yong Ji
Achieving separation of lithium and magnesium with similar radii is crucial for the current lithium extraction technology from salt lakes, which usually possess a high lithium-to-magnesium ratio. Herein, we proposed the facile sequential interfacial polymerization (SIP) approach to construct electronanofiltration membranes (ENFMs) with a bilayer charged structure consisting of a high positively charged surface and a negatively charged sublayer. The trimesoyl chloride (TMC) concentration was adjusted to enhance the −COOH content and negative charge of the polyamide sublayer to promote Li+ migration, and then the quaternized polyethylenimine was introduced to the membrane surface by the SIP process to increase the positive charge density on the surface of the ENFMs, which would block the migration of Mg2+ and enhance the Li+/Mg2+ selectivity of the ENFMs. The optimal quaternary-modified ENFMs achieved outstanding selectivity for Li+/Mg2+ (49.85) and high Li+ flux (4.10 × 10–8 mol cm–2 s–1) at a current density of 10 mA cm–2. Moreover, in simulated brines with low lithium concentration and high Mg2+/Li+ ratio, the optimal ENFMs also displayed elevated Li+/Mg2+ selectivity (>45), highlighting the substantial promise of the membranes for practical applications.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Lele Zhong,Sixian Hu,Xiaojun Yang,Min Yang,Tingting Zhang,Licai Chen,Yunliang Zhao,Shaoxian Song
Montmorillonite (MMT), having special property of hydration expansion, can be easily exfoliated into two-dimensional (2D) nanosheets , which are the promising blocks for making multifunctional nanocomposites . In this work, the exfoliation performances of MMTs from different region including Inner Mongolia (IM), Zhejiang (ZJ) and Liaoning (LN) were investigated from the perspective of layer charge density. All the MMTs were prepared as Na-MMTs first to avoid the effect of the interlaminar ion. Atomic force microscope (AFM) measurements indicated that the exfoliation performance increased as: IM-MMT < ZJ-MMT < LN-MMT. Alkyl ammonium ion exchanged method was applied to study the layer charge density of the MMTs. It was found that the exfoliation performance decreased with the layer charge density of MMT increased. The characterizations of zeta potential , swelling index and BET specific surface area were used to reveal the effects of layer charge density on the exfoliation performance of MMT. The results showed that with increasing the layer charge density, MMT was with more negative zeta potential, thus leading to the stronger binding forces between the layers. The swelling index of LN-MMT was the highest who had the lowest layer charge density, demonstrated by the largest specific surface area and pore diameter after hydration swelling, which explained the best exfoliation behavior of LN-MMT. This study correlates the exfoliation performances with the layer charge density of MMT, and it will provide a guidance to prepare much thinner and larger MMT nanosheets.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Xiongrui Jiang,Lingjie Zhang,Yanhui Miao,Licai Chen,Jiaoyan Liu,Tingting Zhang,Shuai Cheng,Yuhan Song,Yunliang Zhao
Stacking two-dimensional (2D) nanosheets into lamellar membranes holds great promise in the selective separation of Li + and Mg 2+ from salt-lake brines, but revealing the intrinsic effect of nanosheet properties on the ion transport remains a great challenge. The primary reasons are inevitable emerging defects and changes in surface functional groups during nanosheet preparation. Here, we successfully demonstrated the intrinsic dependence of ion separation on the size and layer charge density of 2D building blocks using defect-free and inherently permanent charged clay nanosheets. The smaller-sized nanosheets readily assembled into lamellar membranes with narrower nanochannel dimension, which facilitated the steric hindrance effect to improve the Li + /Mg 2+ selectivity. Experiments and calculations demonstrated the layer charge density-dependent ion separation as well, for which a novel mechanism of intrinsic selective separation driven from the energy barrier difference of ions transport was proposed. Based on the “internal” regulation of the intrinsic nanosheet properties, MMT membranes realized stable and efficient Li + /Mg 2+ separation under extreme conditions, multi-cycle and long-term experiments, with an optimal S Li/Mg of 38.9, superior to most of the reported state-of-the-art membranes. This work reveals the intrinsic interplay of nanosheet properties tuning the ion transport and separation, which will inspire the design and development of advanced 2D lamellar membranes, particularly for sustainable and environmental energy exploitation.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AMERICAN MINERALOGIST
·
2023
·Vol. 108
·期 7
·1357-1367
·
IF 3.1
Qi Tao,Chaogang Xing,Seungyeol Lee,Long Yang,Qingjin Zeng,Shangying Li,Tianqi Zhang,Guanglie Lv,Hongping He,Sridhar Komarneni
An aluminum-free zinc-bearing smectite (Zn-smectite) was synthesized under hydrothermal conditions, together with its magnesium substituted products. Its layer charge calculated by cation exchange capacity (CEC) is 117.4 mmol/100 g. Powder X-ray diffraction (XRD) revealed turbostratic stacking and showed that the d 06l value of the Zn-smectite was >1.525 Å, indicating that it is trioctahedral. Its d 001 value increased from ca.12.8 Å to ca. 16.0 Å after ethylene glycol (EG) saturation. The Zn-smectite did not irreversibly collapse after heating the Li + -saturated sample to 300 °C, suggesting that its layer charge was generated from octahedral-site vacancies (defects). The Zn-smectite resembles zincsilitelike minerals with interlayer Na + and Zn 2+ . The intralayer structure of zincsilite was confirmed by pair distribution function (PDF) analysis, and the whole crystal structure was built and optimized by DFT calculation in the CASTEP module of the Materials Studio software. Synthetic zincsilite is triclinic, space group P 1, and its optimized unit-cell parameters are: a = 5.294 Å, b = 9.162 Å, c = 12.800 Å, α = 90.788°, β = 98.345°, and γ = 90.399°.
研究领域:
矿物学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）