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Surface oxidation, as one of fundamental chemical reactions in metals, greatly affects their properties. Herein, we develop a new quaternary GaInSnZn liquid metal with the melting temperature of 9.7 °C, which is the lowest among all reported Ga-based liquid metals. With high-resolution transmission electron microscopy, we directly observed the oxide layer formed on the surface of the liquid metal. The initially formed oxide layer is revealed to be amorphous and very sensitive to electron beam. Prolonged irradiation results in its structural change from amorphous to crystalline phases. The present finding refreshes the basic understanding of surface oxidization of liquid metals and opens up the possibility of tuning surface structures and morphologies by using electron beam irradiation.

Plasma protein‐induced aggregation of nanoparticles (NPs) is a crucial issue in many applications, such as drug delivery. Although great efforts have been made to investigate the protein adsorption kinetics or protein‐induced NPs coalescence in bulk solutions, limited evidence has been uncovered for interfacial circumstances. Diet, disease, medicine, or senility could thoroughly change interfacial physicochemical properties of the inner lining of blood vessels. Implants including stents and artificial heart valves also have varied and evolutionary interfaces. Hence, there is an urgent need to understand the mechanism behind the non‐specific protein adsorption and NP‐protein aggregation in such interfacial cases. Here, we use evanescent light scattering to observe polystyrene NPs‒fibrinogen aggregation at substrates with varying surface properties. A density‐fluctuation correlation function is utilized to reveal the relaxation dynamics of the aggregates. Both time‐resolved and spatial‐correlated evidence shows that the aging process of such soft materials is out‐of‐equilibrium, where the dynamics faster and slower than exponential can coexist in one single relaxation process. Besides, corona formation, inner stress, and interconnection together determine the microstructure, local adhesion, and structural relaxation of the aggregates, which can further correspond to the protein‐to‐NP ratio as well as the surface chemistry of NPs and substrates. [ABSTRACT FROM AUTHOR]

Herein, pH and light dual-stimuli responsive wormlike micelles (WLMs) were prepared with (4-butylphenyl)-2-(4-trimethylammoniumhexyloxyphen-yl) diazene (C4AzoC6N) and sodium oleate (NaOA). The viscoelasticity of the system was tested by steady state and dynamic rheology. In the alkaline condition, the binary system is a viscoelastic gel-like liquid with a viscosity of up to 230 Pa·s as the presence of the carboxylate group in NaOA, which promotes the formation of WLMs. After the pH of the solution was changed from alkaline to acidic, NaOA was gradually converted into oleic acid, which precipitated out of the system and the viscoelastic system was turned into a cloudy, low-viscosity flowing liquid. On the other hand, the viscosity of the solution could be repeatedly and reversibly switched more than three times without any deterioration upon light trigger due to the cis-trans isomerization of C4AzoC6N. Compared with other surfactants, NaOA is one of cheap and commercially available compounds, which avoids complex organic synthesis or purification processes. Furthermore, the WLMs can be precisely controlled by pH and UV light dual-stimuli, which will have a wide range of applications in large-scale processes, such as in functional materials and fluid drag reducers. [ABSTRACT FROM AUTHOR]

The preparation of monodisperse Pickering emulsions currently can only be achieved using microfluidics or membrane emulsification, limiting its widespread applications in many fields. Here, by simply introducing naturally occurring pollen grains during mechanical emulsification, it becomes extremely feasible to fabricate uniform Pickering emulsions. The process of shearing and turbulence leads to a constant reduction in the size of the droplets of the dispersed phase. The robust exine of the pollen grains in the continuous phase enables them to retain their structural integrity during emulsification, resulting in the formation of a single pollen‐in‐water‐in‐oil structure. Meanwhile, the intrinsic monodispersity of the pollen grains allows for the resulting emulsions to be similarly uniform, and they can be easily collected through centrifugation. As a result, this novel methodology achieves the effective formulation of monodisperse Pickering emulsions in an unprecedented way. Furthermore, the utilization of sporopollenin exine capsules (SECs) as a replacement for pollen, in conjunction with sol–gel interfacial engineering, enables the attainment of "yolk‐shell" dual‐shell microcapsules. This approach not only effectively addresses the issue of cargo leakage in SECs but also imparts exceptional uniformity and stability to the microcapsules. [ABSTRACT FROM AUTHOR]

Stimulus-responsive wormlike micelles (WLMs) have attracted much attention in the past decade. In this work, dual-stimuli (pH and redox reaction) responsive WLMs were prepared with sodium 2,2′-dithiodibenzoate (DTSA) and cetyltrimethylammonium bromide (CTAB). The WLMs can be reversibly switched on and off by an alternating redox reaction originating from the cleavage and reformation of the disulfide bonds in DTSA. Moreover, the WLMs can also respond to pH stimulus. The corresponding responsive behaviors of WLMs were revealed using rheometer, cryogenic transmission electron microscopy, and 1H NMR analyses. The multi-stimuli responsive behavior makes the current system a good candidate for smart control of the sol-gel transition. [ABSTRACT FROM AUTHOR]

Recently, smart wormlike micelles (WLMs) that respond reversibly to external environmental stimuli and display tunable rheological properties have attracted considerable interest. However, the surfactants used in the smart WLMs are always commercially unavailable, and specialized organic synthesis is needed. Here, CO2/N2 and light dual stimuli-responsive WLMs can be prepared by CTAB, cinnamic acid (CA), and cetyl dimethylamine (CDA), which are all commercially available compounds. The zero-shear viscosity (η0) of the ternary system (CTAB-CA-CDA-CO2) reaches a maximum value of 530 Pa·s. Furthermore, the system produced a fast response to the dual stimuli of CO2 and UV light, showing a circulatory gel/sol transition, which reflected changes in the self-assembly from entangled worms to spheres or rod-like micelles. The smart WLMs using cheap and commercially available compounds not only avoid complex organic synthesis or purification, but also allow precise control of the WLMs with dual responsiveness, which have a wide range of applications in large scale processes. [ABSTRACT FROM AUTHOR]