LANGMUIR
·
2015
·
IF 4.457
Jun Yang,Zan Hua,Tao Wang,Bo Wu,Guangming Liu,Guangzhao Zhang
Protein adsorption is an important issue in biorelated fields. We have investigated the protein adsorption on the poly(ionic liquid) (PIL) brushes in the presence of different types of counterions. The protein adsorption is driven by a decrease in osmotic pressure within the brushes with an increase in entropy via the release of counterions. Our study demonstrates that counterion specificity has a significant influence on protein adsorption on the PIL brushes. There have been two different regimes for counterion-specific protein adsorption. When the released counterions cannot bind to the protein surface, the counterion-specific protein adsorption is dominated by the ion-specific counterion condensation within the PIL brushes. If the released counterions can bind to the protein surface, then counterion-specific protein adsorption is dominated by the ion-specific rebinding of released counterions on the protein surface. This work opens up a new opportunity for controlling protein adsorption on polyelectrolyte brushes.
研究领域:
生物物理学
·
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2012
·
IF 3.696
Wenlong Xu,Xiaolin Wang,Zhenhuan Zhong,Aixin Song,Jingcheng Hao
The counterions, including inorganic cations, Na+ and Cs+, and organic cation, (C2H5)4N+, influence the phase behavior and self-assembled structures of the lauric acid (LA) in water. Dissolving LA in NaOH, CsOH, and (C2H5)4NOH (tetraethylammonium hydroxide, TeAOH) solutions, respectively, we observed that the three systems totally exhibited the same phase behavior, from birefringent Lα phase/precipitates (P) → Lα phase → Lα phase/L1 (micelles) → L1. The temperature influence on phase behavior was investigated, and with an increase of temperature, we observed that less phase behavior change occurred in the systems of LA/CsOH/H2O and LA/TeAOH/H2O, while the phase behavior of the LA/NaOH/H2O system exhibited an obvious change. Cryogenic transmission electron microscopy (cryo-TEM) images demonstrated that the different microstructures of Lα phase samples in the three systems existed. For the systems of LA/NaOH/H2O and LA/TeAOH/H2O, uni- and multilamellar vesicles coexist for Lα phase samples, as both the morphology and size of these vesicles are polydisperse. The curvatures of the bilayer membranes of the two systems are considered to vary from positive, zero, and even negative. However, only spherically unilamellar vesicles exist in the system of LA/CsOH/H2O, indicating that the bilayers are more rigid than those in the LA/NaOH/H2O and LA/TeAOH/H2O systems. Through the combination of the Helfrich curvature energy theory and the mass-action model, the effective bending constant K = 0.5 kBT in the LA/CsOH/H2O system was obtained, demonstrating that the unilamellar vesicles are stabilized by thermal fluctuations. A primary discussion for the effect of the nature of counterions on the stability and deformation of the vesicles is presented.
研究领域:
生物物理学
·
胶体与界面化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Yue Li,Li Wei,Wen Zhang,Zhiqiang Dong,Yuping Qiu
Sorption of ionic liquids (ILs) to soil and porous materials as affected by anions was observed, but scarce effort has been focused on addressing the role of counteranions in sorption and the associated underlying mechanisms. In this work, two series of 1-butyl-3-methylimidazolium- (Bmim-) and N -butyl, methyl-benzimidazolium-based (Bmbim-based) ILs coupled with different counteranions were prepared to investigate the effect of anions on IL sorption by soot. The octanol–water partition coefficient ( K ow ) and the ion-pair formation constant at infinite dilution in water ( K IP ° ) of ILs were independently measured to explore the contribution of counteranion-dependent hydrophobicity and ion-pair. A wide range of sorption coefficients ( K d ) of ILs were achieved with values varying from 59.8 to 344.3 L·kg −1 for Bmbim-based ILs and from 253.4 to 489.7 L kg −1 for Bmbim-based ILs. Compared with other anions, bis(trifluoromethanesulphonyl)imide ([Tf 2 N] – ) and hexafluorophosphate ([PF 6 ] − ) exhibit tighter association with IL cations in aqueous solution due to their larger K ow and higher K IP ° . Positive linear relationships between log K IP ° and K d and between log K ow and K d evidenced that the counteranion-dependent sorption of ILs relies on the association strengths of IL cations and counteranions, which further influence the hydrophobicity/hydrophilicity of ion pairs. Compared with that of strongly coordinating anions (such as [CH 3 SO 3 ] − , [CF 3 COO] − , [BF 4 ] − , [CF 3 SO 3 ] − , and [Cl] − ), the addition of weakly coordinating anions (such as [Tf 2 N] – and [PF 6 ] – ) in solution contributes to markedly large sorption enhancement of ILs. Consequently, the contribution of different counteranions on IL sorption is essentially based on the formation of ion pair with different K IP ° and K ow in aqueous solution.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 6
·2049
·
IF 3.748
Xiaojian Zhou,Xiaozhen Zhang,Chunhai Zou,Renhua Chen,Lanlan Cheng,Botao Han,Huafeng Liu
Rutile TiO2pigments codoped with chromophore ion Cr3+and various charge-balancing ions (i.e., counterions species of Sb, Nb, W and Mo) were prepared by a solid-phase reaction method. The effects of the counterions and calcination temperatures on the phase structure, color-rendering and spectroscopic properties, microstructure, and stability of the synthesized pigments were investigated in detail. The results showed that the introduction of 5–10% counterions improved the solubility of Cr3+in the TiO2lattice to form the single-phase rutile pigments calcined at 1100 °C for 2 h. The 10% Cr-doped pigment showed a dark brown color. Depending on the content and type of counterions, the color of the codoped pigments was tailored from yellow to reddish or yellowish-orange to black with different brightness and hue. The influence mechanism of counterions was ascribed to the lattice distortion and variation in the charge balance condition. It was found that the addition of Sb, Nb, or Mo resulted in a remarkable improvement in the NIR reflectance of pigments. The grain growth was inhibited with the codoping of Cr/Sb and Cr/Nb to achieve the nano-sized pigments. In addition, the prepared pigments exhibited good acid and alkali corrosion resistance as well as excellent stability and coloring performance in transparent ceramic glazes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Tao Wang,Ran Kou,Jian Zhang,Renwei Zhu,Hongtao Cai,Guangming Liu
In this work, a negatively charged poly(3-sulfopropyl methacrylate potassium) (PSPMA) brush has been employed as a model system to demonstrate the tuning of the light response of strong polyelectrolyte brushes (SPBs) with counterions. The substitution of K+ counterions by azobenzene-containing counterions (Azo-N+) renders the PSPMA brush light-responsive in aqueous solutions. Nevertheless, the strength of the light response of the PSPMA brush is weak due to the inefficient disassembly of the micelle-like aggregates in the brush upon irradiation with ultraviolet light. Counterion mixtures of Azo-N+ and K+ are employed to realize a strong light response of the PSPMA brush by incorporating a reasonable amount of Azo-N+ counterions into the brush. The strength of the light response of the PSPMA brush can be tuned by the mole ratio of Azo-N+ to K+. Furthermore, properties including the hydration and conformation of the PSPMA brush can be reversibly switched via alternating ultraviolet and visible light irradiation. This work opens up the opportunities available for the use of counterions to tune the light response of SPBs.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Qikai Li,Qing Zhou,Wangping Xu,Long Wen,Jun Li,Biao Deng,Jiajia Zhang,Hu Xu,Weishu Liu
Poly(3,4-ethylene dioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) thermoelectric thin films have attracted significant interest due to their solution-processable manufacturing. However, molecular-level tuning or doping is still a challenge to synergistically boost their thermoelectric performance and mechanically stretchable capabilities. In this work, we report a counterion exchange between ionic liquid bis(x-fluorosulfonyl) amide lithium (Li:nFSI, n = 1, 3, 5) with different sizes of anions and a PEDOT:PSS-induced bipolaron network, which significantly boosted the thermoelectric power factor from 0.8 to 157 μW m K–2 at 235 °C and the maximum tensile strain from 3% to over 30%. The π–π* stacking of the PEDOT polymer chains was fine-tuned by the hydrophobic anions of nFSI–, providing a technical route for constructing a bipolaron network and inducing the transition from hopping transport to band-like transport. Furthermore, we found that the stretchable capabilities, that is, εmax, were connected to the gelation time of the PEDOT:PSS-Li:nFSI aqueous solution. Thus, more fluorine-containing groups resulted in longer gelation times and higher εmax values, which significantly improved the processability of the solution-derived films.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Yanxing Zheng,Jiwei Wang,Xinqiao Tang,Lei Zhang,Fanbao Meng
Viologen-based ionic liquid crystals (VILCs) bearing viologen cations and various counter anions (Br − 1 , CsO − , PF 6 − 1 , CF 3 COO − , TsO − , and BF 4 − 1 ) were prepared using cholesterol, bromobutanoyl chloride, bipyridine and different anionic salts. The chemical structures and the SmC ⁎ phase were identified, and the effect of different anions on both liquid crystalline behavior and ferroelectric property was investigated. Melting temperatures of these VILCs with different anions were similar, but SmC*-isotropic phase transition temperatures were elevated in sequence of TsO − , CsO − , CF3COO − , PF6 − , Br − and BF4 − . They showed different polarization values changed from −9.1 to 9 nC/cm 2 as the electric field changed from −10 V to 10 V. The ferroelectric parameters ± E c , ± P r , and ± P s changed a little due to the different counter anions. The VILC with BF 4 − anion showed the optimal ferroelectric properties in these VILCs series. Unlike conventional ferroelectric liquid crystals, the VILCs displayed asymmetry in the hysteresis loops due to formation of double electrical layers in the ordered SmC ⁎ phase.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Zhaoqi Ye,Yang Zhao,Hongbin Zhang,Zhangping Shi,He Li,Xue Yang,Lei Wang,Lingtao Kong,Chunna Zhang,Zhizheng Sheng,Yahong Zhang,Yi Tang
Hypothesis It is a Holy Grail to realize the goal-oriented synthesis of zeotype crystals via direct thermodynamic/kinetic control of crystallization in the simplest inorganic system. Especially, the most commonly used counter cations (i.e., Na + and K + ) are in turn believed to play merely the role of balancing charges and stabilizing frameworks, which make the simple ion-based morphology/porosity control remain big challenges. Experiments We re-examined the role of Na + and K + to fine-tune the classical/nonclassical crystallization process in a seed-induced system with the simplest composition (Si/Al sources, inorganic alkali, and H 2 O), and proposed an “ion switch” strategy. By analyzing the multiple growth curves, tracking the precursor evolution, and observing epitaxial crystallization behavior , a distinctive “ion switch”-worked nonclassical mechanism was uncovered. Findings By the “ion switch” strategy, ZSM-5 mesocrystals were fine-regulated with diverse architecture from single crystal to nanocrystallite assembly and intracrystal mesopore-enriched crystal. Such simple ions-controlled crystallization was achieved through microstructure heterogeneity of zeolitic building-blocks triggered by different counterions and their corresponding assembly behavior from oriented attachment to random deposition. Furthermore, this protocol can be extended to a wider H 2 O/SiO 2 range, mixed Na + /K + systems, and other alkali metal ions from Li + to Cs + , and ZSM-5 mesocrystals with extended morphologies can be obtained.
研究领域:
材料科学
·
结晶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2019
·
IF 3.683
Hongtao Cai,Ran Kou,Guangming Liu
In this work, poly(sodium styrene sulfonate) brushes have been employed as a precursor to prepare thermosensitive strong polyelectrolyte brushes (SPBs) through a counterion exchange strategy. The substitution of hydrophilic Na+ counterions by hydrophobic tetraalkylphosphonium counterions leads to a thermoresponsivity of the SPBs. The thermosensitive properties including hydration, stiffness, and surface water wettability of the SPBs can be modulated by the type of the tetraalkylphosphonium counterions. Nevertheless, the wet thickness of the SPBs with tetraalkylphosphonium counterions does not exhibit an obvious temperature dependency due to the high steric barrier in the crowded environment of SPBs generated by the large tetraalkylphosphonium counterions. The mixtures of small Na+ counterions and large tetraalkylphosphonium counterions are employed to realize the thermosensitive wet thickness without sacrificing other thermoresponsive properties of the SPBs because the mixed counterions can bring both a certain hydrophobicity and some free space to the brushes. This work opens up the opportunities available for the use of counterions to tune the thermosensitivity of SPBs.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2013
·
IF 4.425
Wanzhen Li,Bin Su
Herein we report the nontrivial effect of counterion size on the electrochemical charging of gold nanoparticle (or called MPC) monolayer films in aqueous electrolyte solutions. The electrochemical charging response was observed with relatively small counterions (e.g., BF 4 − , ClO 4 − and PF 6 − ) but not large ones like bis(trifluoromethylsulfonyl)amide (Tf 2 N − ), tetrakis(pentafluorophenyl)borate (TB − ) or bis(triphenylphosphoranylidene) (BA + ). This effect was explained by the proximity of counterions to the MPC surface, which determines whether the electronic charges on MPCs can be effectively compensated by formation of ion pairs . Only small counterions are permitted to approach the MPC surface by permeating the alkanethiolate layer to achieve a sufficient charge compensation. In contrast, big ions are sterically excluded and thus disfavor the electrochemical charging. This finding helps in further understanding the ion-coupled electrochemical charging mechanism of nanoparticle films.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 6
·1558-1567
·
IF 4.4
Cheng Li,Jing-Wang Cui,Jun-Hao Zhou,Yanqing Xu,Jian-Ke Sun
Aggregation-induced deactivation has long been a challenge in the field of photocatalysis based on molecular porphyrin derivative-based photocatalysts. The development of polyhedral porphyrin cage-based heterogeneous catalysts has shown promise in addressing this issue by preventing intermolecular face-to-face packing. However, this shift towards heterogeneous catalysis comes at the cost of catalytic activity. Herein, we report the design and synthesis of an ionic porphyrin cage, TPPCage·8I, characterized with a high charge density within the skeleton. This strategy effectively circumvents spontaneous aggregation by harnessing the electrostatic repulsion that naturally occurs between adjacent cage hosts. Furthermore, the strategic incorporation of hydrophilic iodine counteranions surrounding the cage not only modulates their solubility, making them uniformly dispersed in the solvent, but also imparts an additional heavy-atom effect. These modifications lead to substantial enhancement in photophysical properties, resulting in extraordinary catalytic activity in the photocatalytic oxidation coupling reaction of benzylamines, with a remarkable conversion rate exceeding 99% and a record turnover frequency (TOF) of 1980.0 h−1, coupled with excellent stability. In addition, the current homogeneous photocatalyst offers ease of recycling through a straightforward exchange process with a robust hydrophobic anion (sodium dodecyl sulfate, SDS).
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 23
·12367-12376
·
IF 7.443
Ying Tang,Beibei Tang,Peiyi Wu
In this work, we report a novel method to prepare a positively charged nanofiltration (NF) membrane by rapid counter-ion exchange of a poly(ionic liquid) (PIL) in aqueous solution, which transforms from being hydrophilic to hydrophobic. A thin PIL layer is deposited on the supporting membrane via a phase separation process induced by an ion exchange reaction along with a self-inhibiting effect, and a series of positively charged NF membranes are obtained. The membrane formation process is mainly dominated by the concentration of the hydrophilic PIL and its counter-ions. In brief, the density of the top layer is predominated both by the PIL and its aqueous counter-ion, and the thickness of the surface layer is mainly determined by the aqueous counter-ion. A streaming potential measurement confirmed that the resultant membrane is positively charged when the pH range is below 11. The pure water flux (PWF) was up to 45.3 L m−2 h−1 under the operating pressure of 0.6 MPa. The rejection to MgCl2 of the membrane reached 84% and decreased in the order of MgCl2, NaCl, MgSO4, and Na2SO4. It also shows a high rejection of about 90% to heavy metallic salts such as CuCl2, NiCl2 and CoCl2. The method based on the hydrophilic–hydrophobic transformation of the PIL provides an alternative way to prepare a charged membrane with high performance.
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
危险品化学品经营许可证（带存储）