scholarly journals Miniaturized catalysis: monolithic, highly porous, large surface area capillary flow reactors constructed in situ from polyhedral oligomeric silsesquioxanes (POSS)

2015 ◽  
Vol 5 (8) ◽  
pp. 3917-3921 ◽  
Author(s):  
P. Scholder ◽  
I. Nischang

A single-step molding process utilizing free-radical cross-linking reaction of vinyl POSS in microliter-sized dimensions leads to hierarchically-structured, mechanically robust, porous hybrid structures tailored for catalytic applications.

2021 ◽  
Vol 10 (2) ◽  
pp. 319
Author(s):  
Hee Cheol Yang ◽  
Won Jong Rhee

Because cancers are heterogeneous, it is evident that multiplexed detection is required to achieve disease diagnosis with high accuracy and specificity. Extracellular vesicles (EVs) have been a subject of great interest as sources of novel biomarkers for cancer liquid biopsy. However, EVs are nano-sized particles that are difficult to handle; thus, it is necessary to develop a method that enables efficient and straightforward EV biomarker detection. In the present study, we developed a method for single step in situ detection of EV surface proteins and inner miRNAs simultaneously using a flow cytometer. CD63 antibody and molecular beacon-21 were investigated for multiplexed biomarker detection in normal and cancer EVs. A phospholipid-polymer-phospholipid conjugate was introduced to induce clustering of the EVs analyzed using nanoparticle tracking analysis, which enhanced the detection signals. As a result, the method could detect and distinguish cancer cell-derived EVs using a flow cytometer. Thus, single step in situ detection of multiple EV biomarkers using a flow cytometer can be applied as a simple, labor- and time-saving, non-invasive liquid biopsy for the diagnosis of various diseases, including cancer.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1985
Author(s):  
Irina Plesco ◽  
Vladimir Ciobanu ◽  
Tudor Braniste ◽  
Veaceslav Ursaki ◽  
Florian Rasch ◽  
...  

A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yunqian He ◽  
Yuelin Wang ◽  
Tie Li

AbstractThe heat conduction and infrared absorption properties of the dielectric film have a great influence on the thermopile performance. Thinning the dielectric film, reducing its contact area with the silicon substrate, or adding high-absorptivity nanomaterials has been proven to be effective in improving thermopiles. However, these methods may result in a decrease in the structural mechanical strength and increases in the fabrication complexity and cost. In this work, a new performance-enhancement strategy for thermopiles by simultaneously controlling the heat conduction and infrared absorption with a TExtured DIelectric (TEDI) film is developed and presented. The TEDI film is formed in situ by a simple hard-molding process that is compatible with the fabrication of traditional thermopiles. Compared to the control FLat DIelectric (FLDI) film, the intrinsic thermal conductance of the TEDI film can be reduced by ~18–30%, while the infrared absorption can be increased by ~7–13%. Correspondingly, the responsivity and detectivity of the fabricated TEDI film-based thermopile can be significantly enhanced by ~38–64%. An optimized TEDI film-based thermopile has achieved a responsivity of 156.89 V·W−1 and a detectivity of 2.16 × 108 cm·Hz1/2·W−1, while the response time constant can remain <12 ms. These results exhibit the great potential of using this strategy to develop high-performance thermopiles and enhance other sensors with heat transfer and/or infrared absorption mechanisms.


InfoMat ◽  
2021 ◽  
Author(s):  
Ramin Rojaee ◽  
Samuel Plunkett ◽  
Md Golam Rasul ◽  
Meng Cheng ◽  
Vahid Jabbari ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lixia Li ◽  
Meng Wang ◽  
Xiandong Wu ◽  
Wenping Yi ◽  
Qiang Xiao

AbstractNanocomposite modification has attracted much attention in improving properties of bio-based polymer coating material for coated fertilizer. Herein two comparable polyhedral oligomeric silsesquioxanes (POSS), with eight poly(ethylene glycol) (PEG) and octaphenyl groups attached to the cage, respectively, were successfully incorporated into thin castor oil-based polyurethane coatings via in-situ polymerization on the urea surface. The nanostructure coatings are environmentally friendly, easy to prepare, and property-tunable. The results show that the vertex group of POSS had a pronounced influence on dispersion level and interaction between polyurethane and POSS that well-tuned the release pattern and period of coated urea, even at the coating rate as low as of 2 wt%. The liquid POSS with long and flexible PEG groups had better compatibility and dispersibility in polyurethane matrix than the solid POSS with rigid octaphenyl groups, as evidenced by SEM/EDS. The unique properties were resulted from the different extents of physical crosslinkings. This modification of bio-based polyurethane coating with POSS provided an alternative method of regulating and controlling the properties of coated fertilizer.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1764
Author(s):  
Lison Rocher ◽  
Andrew S. Ylitalo ◽  
Tiziana Di Luccio ◽  
Riccardo Miscioscia ◽  
Giovanni De Filippo ◽  
...  

In situ synchrotron X-ray scattering was used to reveal the transient microstructure of poly(L-lactide) (PLLA)/tungsten disulfide inorganic nanotubes (WS2NTs) nanocomposites. This microstructure is formed during the blow molding process (“tube expansion”) of an extruded polymer tube, an important step in the manufacturing of PLLA-based bioresorbable vascular scaffolds (BVS). A fundamental understanding of how such a microstructure develops during processing is relevant to two unmet needs in PLLA-based BVS: increasing strength to enable thinner devices and improving radiopacity to enable imaging during implantation. Here, we focus on how the flow generated during tube expansion affects the orientation of the WS2NTs and the formation of polymer crystals by comparing neat PLLA and nanocomposite tubes under different expansion conditions. Surprisingly, the WS2NTs remain oriented along the extrusion direction despite significant strain in the transverse direction while the PLLA crystals (c-axis) form along the circumferential direction of the tube. Although WS2NTs promote the nucleation of PLLA crystals in nanocomposite tubes, crystallization proceeds with largely the same orientation as in neat PLLA tubes. We suggest that the reason for the unusual independence of the orientations of the nanotubes and polymer crystals stems from the favorable interaction between PLLA and WS2NTs. This favorable interaction leads WS2NTs to disperse well in PLLA and strongly orient along the axis of the PLLA tube during extrusion. As a consequence, the nanotubes are aligned orthogonally to the circumferential stretching direction, which appears to decouple the orientations of PLLA crystals and WS2NTs.


2012 ◽  
Vol 12 (9) ◽  
pp. 1220-1231 ◽  
Author(s):  
Adrian Sulistio ◽  
Anton Blencowe ◽  
Jiapei Wang ◽  
Gary Bryant ◽  
Xiaoqing Zhang ◽  
...  
Keyword(s):  

2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.


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