COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Zilu Li,Kefei Zhao,Yue Wang,Zirui Zheng,Chenhui Zhang,Yuxia Gao,Fengpei Du
Impact and spread of droplet on superhydrophobic surface are ubiquitous in inkjet printing , pesticide spraying, paint coating, and other fields. However, due to the extremely water-repellent properties of superhydrophobic surface, droplets frequently splash or roll off, causing great waste and serious environmental problems. Thus, searching for an effective strategy to regulate the droplet splash and spread on superhydrophobic surfaces is of remarkable significance. To address the above issues, herein, we demonstrate the controllable regulation on superhydrophobic lotus leaf surface by tuning the double-chain length of surfactants . The outcomes indicate different regularities for droplet splash in a short time (~10 ms) and spread in a relatively long period (~100 s). It can be concluded that dynamic surface tension of surfactant, diffusion rate of surfactant from the bulk to the interface, and assembly disaggregation rate dominate the impact process, whereas the adsorption kinetic and effectiveness of surfactant along with the spreading driving force determine the wetting transition. Surfactant owning suitable hydrophilic and hydrophobic ratio, fast diffusion rate, and unstable assembly could inhibit droplet splash and improve spreading pronouncedly, thereby enhancing the droplet deposition on superhydrophobic surfaces. This study makes original contribution to screen suitable surfactants from the structural aspects, especially double-chain length, which has not been treated in much detail to date. Our work not only creates a big impetus in illuminating the mechanism of surfactant molecular structure on droplet deposition processes but also greatly expands the applications of surfactant in many fields.
研究领域:
胶体与界面化学
·
农业化学
·
材料科学
·
流体力学
·
环境科学
·
应用物理
·
纳米科技
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2021
·
IF 3.995
Jianhua Zhou,Hong Li,Yannan Li,Xiang Li
Cellulose nanocrystals (CNCs) were modified using an amphiphilic triblock copolymer [poly(2-(dimethylamino) ethyl methacrylate)- b -poly(glycidyl methacrylate)- b -poly(2,2,3,4,4,4-hexafluorobutyl acrylate) (PDMAEMA- b -PGMA- b -PHFBA)] bearing epoxy functionalities located in middle segment of PGMA, which were used to react with the hydroxyl groups on the surface of the CNCs. The triblock copolymer was synthesized via a reversible addition fragmentation chain transfer (RAFT) polymerization reaction between 2-(dimethylamino) ethyl methacrylate, glycidyl methacrylate and 2,2,3,4,4,4-hexafluorobutyl acrylate, and characterized using 1 H-NMR spectroscopy and size exclusion chromatography (SEC). The successful modification of the CNCs was demonstrated by means of FT-IR, TGA , TEM , XRD and XPS . In addition, the surface properties of the modified CNCs were studied using water contact angle and surface tension studies. When compared with the pristine CNCs, the modified CNCs exhibited a higher contact angle and lower surface tension. Good dispersion of the modified CNCs was observed in different polar solvents, such as water, THF, DMF , CHCl 3 and toluene. The modified CNCs exhibited pH responsive properties, which were measured using dynamic light scattering (DLS). In addition, the stability of Pickering emulsions stabilized by PDMAEMA- g -CNC- g -PHFBA decreased with time or increasing pH. The droplet size increased gradually upon increasing the pH. This work provides a method to design sophisticated CNC-based materials, which benefit from both the intrinsic properties of the CNCs and the new characteristics conferred by the multifunctional grafted chains.
研究领域:
高分子化学
·
纳米材料科学
·
胶体与界面化学
·
生物基功能材料
·
智能响应材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Pan Zhang,Lemeng Wang,Chunjie Lu,Mengying Li,Shujun Yu,Dong Fu
The surface tensions of 2‑diethylaminoethanol (DEAE)‑ N ‑(2‑aminoethyl)ethanolamine (AEEA), DEAE‑ N ‑methyl‑1,3‑propane‑diamine (MAPA) and DEAE‑1,4‑butanediamine (BDA) aqueous solutions have been measured by using the BZY-1 surface tension meter. The mass fractions of DEAE and AEEA/MAPA/BDA respectively ranged from 0.300 to 0.500 and 0.050 to 0.150. The temperature ranged from 303.2 K to 323.2 K. A thermodynamic equation was proposed to model the surface tension and the calculated results agreed well with the experiments. The effects of temperature and mass fraction of amines on the surface tension were demonstrated on the basis of experiments and calculations. The surface thermodynamics including surface enthalpy and surface entropy of blended amine aqueous solutions were also determined, and their temperature and mass fraction dependences were analyzed.
研究领域:
物理化学
·
溶液化学
·
热力学
·
表面科学
·
化工材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2013
·
IF 2.108
Pei Zhang,Hui Wang,Xia Liu,Xuefeng Shi,Jian Zhang,Guang Yang,Keji Sun,Jinben Wang
The dynamic surface tension and dilational viscoelasticity properties of amphiphilic polyamidoamine (PAMAM) dendrimers were investigated to probe the hydrophobic chain effect on the interfacial properties and the demulsification behaviors. The values of dynamic parameters n and t * representing diffusion speed of the molecules obtained according to the Rosen equation decreased with the increasing of bulk concentration. Taking the hydrophobic effect into consideration, the t * values decreased and n values increased with the increase of alkyl chain length, suggesting easier adsorption and faster diffusion for longer hydrophobic chain which was opposite to the tendency of traditional surfactants. Further dilational viscoelasticity studies demonstrated that the properties referring to adsorption and exchange-diffusion were probably affected by the aggregates conformation at the interface. Subsequently, from the demulsification experiments a conclusion can be drawn that the amphiphilic dendrimers with branched dendritic structure possesses superior properties of breaking W/O crude oil emulsions, showing a certain correlation to the dilational viscoelasticity properties.
研究领域:
胶体与界面化学
·
石油化学
·
高分子科学
·
流变学
·
表面活性剂化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）