RSC Advances
·
2017
·Vol. 7
·期 12
·7052-7059
·
IF 3.108
Ai Hongru,Li Xiangqin,Shi Shuyan,Zhang Ying,Liu Tianqing
The Wenzel roughness factor r is one of the most important parameters to characterize a super-hydrophobic surface. In this study, in order to prove the feasibility of using laser scanning confocal microscopy (LSCM) to measure the roughness factor r, the detected r values by LSCM on texture-regular surfaces were compared with those calculated firstly, and then the r values measured by LSCM for texture-irregular rough surfaces were compared with those measured by AFM. The results show that the r values of texture-regular surfaces measured by LSCM are close to those calculated, and the LSCM measured r values of texture-irregular surfaces with small roughness are consistent with those measured by AFM. Moreover, the r values of texture-irregular surfaces with large roughness can only be measured by LSCM, the detected r values of three such super-hydrophobic surfaces are 2.13 ± 0.01, 2.12 ± 0.01 and 2.13 ± 0.02, respectively. In addition, it is proved that the r measured by LSCM as a line length ratio is equal to the original definition of roughness factor as the ratio of actual area of solid surface to the horizontal projected area. Consequently, it is reliable to measure the r value of a texture-irregular surface with large roughness in micro or submicro scale by LSCM.
研究领域:
材料科学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2022
·
IF 5.907
Yingya Wang,Lingyu Ran,Lingya Ma,Runliang Zhu,Jingming Wei,Hongmei Liu,Yunfei Xi,Jianxi Zhu,Hongping He
The variable structural characteristics of montmorillonite (Mnt) in salt solutions depend not only on the quantity and distribution of the Mnt layer charge, but also on the specificity of counterions, including their radius, valence, concentration, and hydratability. In order to determine the nanoscale chemomechanical processes in a clay mineral–water–salt system, in situ X-ray diffraction (XRD) and atomic force microscopy (AFM) methods were used to investigate the structural variations of Mnt caused by different counterion species ( e.g. , Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , and Sr 2+ ) at different concentrations (0.2–3.0 M). With an increasing concentration of counterions, separation of water molecules from the interlayer space of more weakly hydrated cations (Cs + , Rb + , and K + ) is faster than for the more strongly hydrated cations (Li + , Na + , Mg 2+ , Ca 2+ , and Sr 2+ ), water molecules are lost more slowly from the hydration shell, which remains stable even at high counterion concentrations . The sequential ion exchange in a monolayer Mnt observed by in situ AFM is consistent with the d (001) results from the real-time XRD analysis . Moreover, various defects on Mnt surfaces were visible in the high-resolution AFM images, which restrict the spatial arrangement of adsorbed cations. The water molecule partitioning between the interlayers in Mnt is controlled by the specificity of the counterions, and the cations can spontaneously form ordered structures on the surface of Mnt. These nonclassical interfacial phenomena occurred in the electric double layer (EDL) is controlled by the hydration of counterions, the surface structure and the charge distribution of Mnt.
研究领域:
矿物学
·
材料科学
·
界面化学
✓ 已验证
DOI
高影响因子
Nano Research
·
2020
·Vol. 13
·期 2
·412-418
·
IF 8.183
Yang Kai,Jia Langlang,Liu Xinhua,Wang Zijian,Wang Yan,Li Yiwei,Chen Haibiao,Wu Billy,Yang Luyi,Pan Feng
Graphite as a positive electrode material of dual ion batteries (DIBs) has attracted tremendous attentions for its advantages including low lost, high working voltage and high energy density. However, very few literatures regarding to the real-time observation of anion intercalation behavior and surface evolution of graphite in DIBs have been reported. Herein, we use in situ atomic force microscope (AFM) to directly observe the intercalation/de-intercalation processes of PF 6 − in graphite in real time. First, by measuring the change in the distance between graphene layers during intercalation, we found that PF 6 − intercalates in one of every three graphite layers and the intercalation speed is measured to be 2 µm·min −1 . Second, graphite will wrinkle and suffer structural damages at high voltages, along with severe electrolyte decomposition on the surface. These findings provide useful information for further optimizing the capacity and the stability of graphite anode in DIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Lin Cao,Jiaqi Li,Yukun Song,Shuang Cong,Haitao Wang,Mingqian Tan
Foodborne nanoparticles have attracted considerable interest due to their distinctive fluorescence and physicochemical properties. The discovery of vinegar carbon dots (VCDs) has drawn our attention to study their effect on human plasma protein. Herein, spectral, constructional, morphological, and enzymatic activity assessments were carried out to investigate the interaction of VCDs with human hemoglobin (HHb). The intrinsic fluorescence of HHb was quenched significantly by the VCDs through a static quenching process. Furthermore, binding constants and important thermodynamic parameters were calculated, the negative enthalpy and entropy changes were accompanied by a negative Gibbs energy, which proposed the binding between VCDs with HHb was spontaneous. Moreover, negative enthalpy and entropy change corroborated the involvement of van der Waals force and hydrogen bonds in the binding process. Results from FTIR, atomic force microscopy and circular dichroism revealed change of HHB after binding with VCDs although their essential morphological features were unaffected. The esterase activity of HHb decreased after VCDs treatment in a dose-dependent manner, which further confirmed the effect of VCDs on HHb. The results offered detailed information about the interaction between VCDs and HHb.
研究领域:
纳米技术
·
生物化学
·
光谱学
·
热力学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 52
·38806-38814
·
IF 3.9
Rui Zhang,Yida Zhang,Zili Li,Xiaobin Xu,Quan Xu
Boston ivy has received much attention from researchers owing to its exceptional climbing abilities. However, many aspects of their adhesion behavior remain unresolved. Our research has discovered a phenomenon of oxidation and discoloration in Boston ivy pads, which leads to a significant decrease in adhesion force. In this study, we conducted a comprehensive investigation into the oxidation discoloration phenomenon. Through XPS analysis, we confirmed that the transition from Fe2+ to Fe3+ in the pad is the primary cause of the oxidation discoloration reaction. Furthermore, by conducting in situ adhesion testing using AFM, we observed a decrease in adhesion during the oxidation of iron ions. The magnitude of adhesion is closely related to the amount of pyrocatechol. Following the oxidation reaction, iron ions chelate with more pyrocatechol, resulting in a decrease in the available pyrocatechol content for adhesion. To validate this mechanism, we designed and prepared a biomimetic composite adhesion surface of a PDMS hydrogel. This composite surface improved oxidation resistance through the hydrogel, demonstrating improved adhesion performance. These findings offer promising prospects for the application of bionic materials in various fields.
研究领域:
植物学
·
材料科学
·
生物力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2017
·
IF 4.536
Yong Xiong,Tiantian Cao,Qian Chen,Zhen Li,Yue Yang,Shengming Xu,Shiling Yuan,Johan Sjöblom,Zhenghe Xu
Molecular dynamics simulation was used to investigate the adsorption of a polyaromatic compound (C5Pe) on silica surfaces from organic solvents. Heptane and toluene were used as oil phase to probe the effect of solvent properties on C5Pe adsorption. The results showed that C5Pe molecules tend to adsorb rapidly on silica surface in heptane and assemble to form long strip shaped aggregates, while in toluene C5Pe prefers to form aggregates which remain mostly in bulk oil phase. The van der Waals interactions were found to provide the largest contribution for driving the adsorption of C5Pe from heptane solutions due to the protonated state of C5Pe molecules. The calculated lower system free energy of C5Pe adsorption from heptane than from toluene corresponded well with the observed stronger adsorption of C5Pe from heptane than from toluene. AFM imaging confirmed the observed trend of C5Pe adsorption on silica from heptane and toluene.
研究领域:
物理化学
·
材料科学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jiayi Wu,Rui Wang,Yuyao Zhang,Baoliang Chen,Xiaoying Zhu
The interaction force of a typical antibiotic molecule during adsorption has never been experimentally determined and fractionated, which hindered the evolution of removal strategies. In this study, sulfamethoxazole (SMX) as a typical antibiotic was stably immobilized onto an atomic force microscopy (AFM) tip without affecting original properties. The SMX modified AFM tip visualized the potential adsorption sites on a graphene oxide (GO) nanosheet for the first time by mapping the SMX adhesion force distribution. Moreover, the interaction force of a single SMX molecule to GO was determined at 38.6 pN which was subsequently fractionated into the hydrophobic (17.9 pN) and π-π (160.0 pN) attractions as well as the electrostatic repulsion (− 139.3 pN) at pH: 5.7. As compared with highly-ordered pyrolytic graphite (HOPG), the introduced oxygen containing groups on GO not only reduced the hydrophobic interaction but also generated an opposite electrostatic repulsion force to SMX. This study experimentally and theoretically revealed the adhesion mechanisms of SMX and potentially other sulfonamide antibiotics in molecular level, which may contribute to the study of antibiotic environmental transportation and the development of next-generation antibiotic remediation protocols.
研究领域:
环境科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2016
·Vol. 32
·期 9
·2318-2326
·
IF 0.844
LIU Shan-Shan,JI Shan,CHEN Qi-Bin,PENG Chang-Jun,LIU Hong-Lai
A supramolecular polymer brush composed of polyvinylpyrrolidone-cholesterol (PVP-Chol) was fabricated based on intermolecular hydrogen bonding between the ketone groups of the PVP moieties and the hydroxyl groups of the cholesterol, both in solution and at the air/water interface. These
confirmations were confirmed by Fourier transform infrared (FT-IR) spectroscopy, surface pressure versus molecular area (π-A) isotherms, and atomic force microscopy (AFM). At surface pressures up to 2.5 mN·m-1, the interfacial film was composed of cholesterol-enriched
regions and PVP-Chol nanofibril domains. Interestingly, oversurface pressures, the structure of the PVP-Chol-enriched domains evolved frominitial irregular shapes, to crescent and heart-shaped zones, and then to circular shapes. This transition indicated the controllability of such domains
during compression of a complex monolayer at relatively low surface pressures. Above 2.5 mN·m-1, the circular PVP-Chol domains disappeared and fibrous aggregates were formed at the air/water interface. The height of the comb-like PVP-Chol nanofibrils could be reversibly varied
between approximately 4.3 and 1.8 nm by adjusting the voltage applied to piezoceramics during the AFM scanning process. These results demonstrate that the reversible structural transformation of the PVP-Chol complex from cylindrical to elliptic cylindrical is induced by the applied force of
the AFM tip up to a value of 1.0 mN·m-1. These data provide important and useful information that improves our understanding of the relationship between the structures and performances of supramolecular polymer brushes, and should extend the range of applications of cholesterol-functionalized
polymers fabricated via a simple mixing strategy.
研究领域:
材料科学
·
表面化学
·
生物材料
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2018
·
IF 3.23
Saizhen Jin,Qing Shi,Qi Li,Leming Ou,Kai Ouyang
The effect of various calcium ionic concentration on the adsorption of carboxymethyl cellulose (CMC) onto talc surface has been investigated using flotation tests, adsorption measurements and tapping mode atomic force microscopy (AFM) imaging. Microflotation tests indicated that the depression of talc depressed by CMC was increasingly enhanced with the increase of Ca 2+ at pH 8.5. And within the pH range of 2–11.5, in the presence of Ca 2+ , the depression of talc by CMC could be facilitated by Ca 2+ stably. Adsorption experiments confirmed that with the increase of Ca 2+ , the adsorbed CMC on talc increased at pH 8.5. AFM imaging revealed the morphology of adsorbed CMC were different in the absence and presence of various Ca 2+ ions concentration. In the absence of Ca 2+ ions, the morphology of adsorbed CMC consisted of randomly distributed salient point domains with a lower area fraction of surface coverage; in the presence of 10 −4 mol/L Ca 2+ ions the morphology mingled with salient point and reticulate adsorption; in the presence of 10 −3 and 10 −2 mol/L Ca 2+ ions the morphology is a reticulate multilayer adsorption with a higher area fraction of surface coverage.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2025
·
IF 4.6
Qiming Zhuo,Decheng Chen,Zenan Wang,Wei Han,Yongming Song,Wenli Liu,Peng Xi
The separation of chalcopyrite and molybdenite in porphyry copper–molybdenum ores is challenging owing to their similar floatabilities, making the use of depressants necessary. Inorganic depressants are commonly employed in the flotation industry to increase the difference in hydrophobicity between chalcopyrite and molybdenite; however, these depressants pose significant environmental risks. Recently, novel organic depressants have attracted considerable interest because of their abundance and low toxicity. This study investigated the use of 2,5-dimercapto-1,3,4-thiadiazole (DMTD), an activator recently employed in copper oxide flotation, as a depressant for the separation of chalcopyrite and molybdenite. Micro–flotation experiments demonstrated that DMTD exhibits a notable selective depression effect, significantly suppressing the flotation of chalcopyrite without adversely affecting the flotation of molybdenite. Furthermore, DMTD maintained its depression effect on chalcopyrite flotation even in the presence of xanthate. Contact angle measurements were used to analyze changes in hydrophobicity, corroborating the micro–flotation results, while SEM-EDS elemental distribution maps further confirmed the selective adsorption of DMTD on the chalcopyrite surface. XPS and AFM analyses were conducted to elucidate the microscale interaction mechanism between DMTD and chalcopyrite. The specific interaction sites on the chalcopyrite surface were identified through changes in elemental binding energies, while the evolution of surface morphology revealed how DMTD interacts with chalcopyrite in the xanthate system.
研究领域:
矿物加工
·
冶金学
·
表面化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2020
·
IF 4.231
Chunhua Wang,Lan Yang,Yujing He,Huining Xiao,Wei Lin
In this work, the vinyl groups were introduced onto gelatin to create methacrylated gelatin nanoparticles (MA-GNP) as crosslinking centers for fabricating macromolecular microsphere composite (MMC) hydrogels. The MA-GNPs with an average size of ~100 nm, measured with dynamic light scattering , were also visualized using AFM . The presence of C C bonds in the nanoparticles was further confirmed with the proton NMR . Then, the MA-GNP was incorporated as a cross-linker to synthesize MMC hydrogels using acrylamide as the monomer . The resulting hydrogels are porous with tunable pore sizes; and exhibit the improved compressive resistance and elasticity. Increasing the dosage of MA-GNP appropriately led to the reduction of the equilibrium swelling ratio but improved thermal stability of the gels. Moreover, the MA-GNP can endow the gels with enhanced biocompatibility. Overall, the novel protein-based nanospheres are of great potential as both nano-crosslinker and reinforcer to create polymer hydrogels with tailored properties.
研究领域:
材料科学
·
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xiang Yan,Caili Dai,Ruoyu Wang,He Liu,Siwei Meng,Xu Jin,Yong Hu,Yining Wu
Countercurrent imbibition of the fracturing fluid is of much significance for enhancing oil production in tight oil reservoirs during the shut-in period after hydraulic fracturing. The addition of enhanced imbibition agents such as surfactants and nanoparticles into the polymer-based fracturing fluid is conducive to oil production. How different types of imbibition agents affect oil recovery and the applicable conditions for different imbibition agents, however, still need to be clarified. In this article, we used low-field nuclear magnetic resonance (NMR) to measure the one-dimensional (1D) oil signal profiles along the imbibition direction during the countercurrent imbibition process and determine the imbibition distance and water saturation of different imbibition agents including polymer, surfactant, nano-silica (NS) and NS-surfactant complexes. Moreover, by measuring oil–water interfacial tension (IFT), and the adhesion forces between alkanes and the hydrophobic surfaces before/after the imbibition agent treatments by atomic force microscope (AFM), the IFT reduction and wettability alteration abilities of these agents were evaluated. After the NS-surfactant complexes treatment, the adhesion force which represents the force required to pull off oil from the rock surface became the lowest (15.81 pN), merely a quarter of that of NS (73.48 pN) and surfactant (70.01 pN), indicating a superior capability of NS-surfactant to improve wettability. The imbibition efficiency of the four systems in terms of imbibition distance and oil recovery was: NS-surfactant complexes: 38.43 mm 13.2 % > nonionic surfactant: 32.15 mm 9.0 % > NS: 25.88 mm 7.6 % > polymer: 17.64 mm 4.9 %. NS-surfactant nanofluid displayed the longest imbibition distance and highest water saturation, thus possessing the highest imbibition oil recovery. Nonionic surfactant with an IFT of 4.19 mN/m could greatly reduce the IFT compared with NS (35.98 mN/m), but the recovery enhancement induced by IFT reduction was not significant. In contrast, the increase in oil recovery by wettability alteration was distinctly higher than that by IFT reduction, as indicated by the recovery difference between NS-surfactant complexes and surfactant. Accordingly, wettability alteration is the primary mechanism to enhance imbibition oil recovery when ultralow IFT cannot be achieved. This research provides guidance on which type of imbibition agent should be selected to improve imbibition efficiency.
研究领域:
石油工程
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）