RESUMO
In this study, we proposed a method for fabricating Janus sheets using biological "microflowers" as a sacrificial template. The microflower-templated Janus sheets (MF-JNSs) were employed as a foam stabilizer in foam separation of the whey soybean protein (WSP). The MF-JNSs took inorganic hybrid microflowers (BSA@Cu3 (PO4)2-MF) as template, followed by the sequential attachment of protamine and silica to the surface of the BSA@Cu3(PO4)2-MF. Subsequently, the template was removed using ethylenediaminetetraacetic acid after the silicon dioxide was modified by 3-(methacryloyloxy) propyl trimethoxysilane. Upon template dissolution, the modified silica layer, lacking support from the core, fractured to form the MF-JNSs. This method omitted the step of treating the hollow ball by external force and obtained Janus sheets in one step, indicating that it was simple and feasible. The morphology, structure, and composition of the MF-JNSs were analyzed by SEM, TEM, AFM, XRD, and FT-IR. The MF-JNSs were found to delay the breakage time of the Pickering emulsion, demonstrating their emulsion stabilizing capability. Importantly, they significantly enhanced the foam half-life and foam height of soybean whey wastewater (SWW). Moreover, the recovery percentage and enrichment ratio of WSP, separated from SWW by foam separation, were improved to 81 ± 0.28 and 1.20 ± 0.05%, respectively.
RESUMO
The current study presents a scalable approach for the preparation of temperature-responsive PEG/SiO2/PNIPAM-PEA Janus particles and, for the first time, investigates their potential applications in stabilizing foam and defoaming by adjusting the temperature. The method utilizes a (W1 + O)/W2 emulsion system, which incorporates appropriate surfactants to stabilize the emulsion and prevent rapid dissolution of the hydrophilic triblock polymer PEG-b-PTEPM-b-PNIPAM in water. The PEG/SiO2/PNIPAM-PEA Janus particles with temperature-responsive characteristics were synthesized in a single step that combined the sol-gel reaction and photoinduced free radical polymerization. The contact angle of the hydrophilic PEG/SiO2/PNIPAM surface was measured to be 54.7 ± 0.1°, while the contact angle of the hydrophobic PEA surface was found to be 122.4 ± 0.1°. By incorporating PEG/SiO2/PNIPAM-PEA Janus particles at a temperature of 25 °C, the foam's half-life is significantly prolonged from 42 s to nearly 30 min. However, with an increase in temperature to 50 °C, the foam's half-life rapidly diminished to only 44 s. This innovative application effectively enhances foam stabilization at low temperatures and facilitates the rapid dissipation of foam at high temperatures.
RESUMO
This study examined the long-term effects of the Wenchuan earthquake among adult survivors. Specifically, it explored the role of perceived social support (PSS) in the relationship between rumination and posttraumatic growth (PTG) and posttraumatic stress disorder (PTSD) symptoms. Data were collected from March to July 2020 using a youth survivor sample (n = 476) of the 2008 Wenchuan earthquake. Participants were divided into three groups depending on their age when the quake occurred: 6-11 years (n = 227), 12-15 years (n = 83), 16-19 years (n = 166). The results indicated that long-term PTG and PTSD symptom levels varied by age group. Both intrusive and deliberate ruminations had a significant effect on PTG as well as PTSD symptoms. PSS played a mediating role between rumination and PTG, and the mediation mechanisms varied by age group (developmental stages). Moderated analyses revealed that PSS from significant others significantly buffered the indirect effect of rumination on PTSD symptoms. Our findings demonstrated the universal nature of traumatic events encountered during childhood and adolescence development and underscore the importance of examining the developmental context of PTG in investigations on traumatic experiences and their consequences.
