How low can you go? Polybenzoxazines can display surface free energies which are even lower than that of pure poly(tetrafluoroethylene). The contact angles and surface free energies were monitored ...during the polymerizations (see graph for an example). These materials are cheaper to prepare and easier to process than fluoropolymers.
POSS related polymer nanocomposites Kuo, Shiao-Wei; Chang, Feng-Chih
Progress in polymer science,
12/2011, Letnik:
36, Številka:
12
Journal Article
Recenzirano
This review describes the syntheses of polyhedral oligomeric silsesquioxane (T
8-POSS) compounds, the miscibility of POSS derivatives and polymers, the preparation of both multifunctional and ...monofunctional monomers and polymers containing POSS including styryl-POSS, methacrylate-POSS, norbornyl–POSS, vinyl-POSS, epoxy–POSS, phenolic–POSS, benzoxazine–POSS, amine-POSS, and hydroxyl-POSS. The thermal, dynamic mechanical, electrical, and surface properties of POSS-related polymeric nanocomposites prepared from both monofunctional and multifunctional POSS monomers are discussed. In addition, we describe the applications of several high-performance POSS nanocomposites in such systems as light emitting diodes, liquid crystals, photo-resist materials, low-dielectric constant materials, self-assembled block copolymers, and nanoparticles.
Abstract
Effective water use is currently a critical global challenge needed to prevent water shortages and has attracted significant research attention. The realization of solar-driven water ...evaporation by using effective converters has attracted considerable attention in recent years owing to its potential for seawater desalination and wastewater treatment. Consequently, this paper proposes a simple two-step method to prepare low-cost and self-floating photothermal converters from waste coffee grounds. First, the coffee grounds were carbonized at 1,000 °C to develop broadband absorption, and the carbonized coffee grounds were modified using hydrophobic silane to enhance the water-floatation property of the grounds. The prepared hydrophobic carbonized coffee grounds exhibited good performance for desalination and water purification under sunlight irradiation. The self-floatation ability, low cost, well solar evaporation performance, and easy preparation contribute to the promising potential of using hydrophobic carbonized coffee grounds infuture steps toward eco-friendly desalination procedures.
In this study, two different types of hybrid porous organic polymers (POPs), polyhedral oligomeric silsesquioxane tetraphenylpyrazine (POSS-TPP) and tetraphenylethene (POSS-TPE), were successfully ...synthesized through the Friedel−Crafts polymerization of tetraphenylpyrazine (TPP) and tetraphenylethene (TPE), respectively, with octavinylsilsesquioxane (OVS) as node building blocks, in the presence of anhydrous FeCl3 as a catalyst and 1,2-dichloroethane at 60 °C. Based on N2 adsorption and thermogravimetric analyses, the resulting hybrid porous materials displayed high surface areas (270 m2/g for POSS-TPP and 741 m2/g for POSS-TPE) and outstanding thermal stabilities. Furthermore, as-prepared POSS-TPP exhibited a high carbon dioxide capacity (1.63 mmol/g at 298 K and 2.88 mmol/g at 273 K) with an excellent high adsorption capacity for iodine, reaching up to 363 mg/g, compared with the POSS-TPE (309 mg/g).
Since early diagnosis of sepsis may assist clinicians in initiating timely, effective, and prognosis-improving antibiotic therapy, we developed an integrated microfluidic chip (IMC) for rapid ...isolation of both Gram-positive and Gram-negative bacteria from blood. The device comprised a membrane-based filtration module (90 min operating time), a bacteria-capturing module using a micro-mixer containing magnetic beads coated with "flexible neck" regions of mannose-binding lectin proteins for bacteria capture (20 min), and a miniature polymerase chain reaction (PCR) module for bacteria identification (90 min
via
TaqMan® probe technology). The filter separated all white blood cells and 99.5% of red blood cells from bacteria, which were captured at rates approaching 85%. The PCR assay's limit of detection was 5 colony-forming units (CFU) per reaction, and the entire process was completed in only 4 h. Since this is far less than that for culture-based approaches, this IMC may serve as a promising device for detection of sepsis.
Isolation and identification of bacteria from human blood were automated on an integrated microfluidic system for sepsis-inducing bacteria.
In this study, we synthesized three hybrid microporous polymers through Heck couplings of octavinylsilsesquioxane (OVS) with 2,5-bis(4-bromophenyl)-1,3,4-oxadiazole (OXD-Br2), tetrabromothiophene ...(Th-Br4), and 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene (TPTh-Br2), obtaining the porous organic–inorganic polymers (POIPs) POSS-OXD, POSS-Th, and POSS-TPTh, respectively. Fourier transform infrared spectroscopy and solid state 13C and 29Si NMR spectroscopy confirmed their chemical structures. Thermogravimetric analysis revealed that, among these three systems, the POSS-Th POIP possessed the highest thermal stability (T5: 586 °C; T10: 785 °C; char yield: 90 wt%), presumably because of a strongly crosslinked network formed between its OVS and Th moieties. Furthermore, the specific capacity of the POSS-TPTh POIP (354 F g−1) at 0.5 A g−1 was higher than those of the POSS-Th (213 F g−1) and POSS-OXD (119 F g−1) POIPs. We attribute the superior electrochemical properties of the POSS-TPTh POIP to its high surface area and the presence of electron-rich phenyl groups within its structure.
In this study we prepared cyanate ester–functionalized double-decker silsesquioxane (DDSQ) nanoparticles through a sequence of hydrosilylation of nadic anhydride (ND) with DDSQ and then treat with ...4-aminophenol to provide DDSQ-ND-OH, and reaction with cyanogen bromide (BrCN) to form DDSQ-ND-OCN (a bis-phenyl cyanate ester DDSQ). After thermal curing of DDSQ-ND-OCN, we obtained mesoporous poly(cyanate ester) (PCE)/DDSQ frameworks that displayed high thermal stabilities and char yields since the inorganic DDSQ nanoparticles were dispersed in the PCE matrix homogeneously, as revealed using electron microscopy. Thermal polymerization at 210 °C provided a PCE/DDSQ framework having a thermal decomposition temperature (516 °C) and char yield (70 wt%); these values increased to 600 °C and 81 wt%, respectively, after thermal treatment at 420 °C. More interestingly, these mesoporous PCE/DDSQ frameworks displayed electrochemical properties better than those of other non-carbonized materials.
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•Mesoporous Poly(cyanate ester)–functionalized DDSQ was synthesized.•These mesoporous PCE/DDSQ frameworks displayed good electrochemical properties.•High thermal stabilities since DDSQ nanoparticles dispersed in PCE matrix homogeneously.•Hexagonally packed cylindrical porous structure collapsed after thermal treatment.
Two-stage exchange arthroplasty remains a popular surgical treatment for patients with chronic periprosthetic joint infection (PJI). Patients who do not receive reimplantation were largely overlooked ...in the current literature. We aimed at investigating the clinical outcomes of these patients.
Our institutional PJI database was retrospectively reviewed to identify 616 patients (237 hips, 379 knees) who were treated with an intended 2-stage exchange. Of them, 111 (18%) did not receive reimplantation within a minimum follow-up of 1 year. Chart review and targeted interviews were performed to elucidate the cause of attrition. Patients were considered to have failed treatment in the absence of reimplantation if they remained medically unfit for reimplantation, underwent a salvage procedure, or died during the study period.
Of the 111 patients without reimplantation, 29 (26.1%) did well with their retained spacer and were unwilling to proceed with reimplantation, 23 (20.7%) underwent salvage procedures, and the remaining 59 (53.2%) were considered medically unfit for reimplantation, with 34 of them dying within 1 year of initial spacer insertion. The overall success rate for 2-stage exchange cohort at 2 years was 65.7% when treatment failure without reimplantation was taken into account. Several factors associated with increased risk of treatment failure without reimplantation were identified using a multivariate regression model.
Almost 1 in 5 patients may never receive the intended reimplantation. Among many reasons for attrition, mortality appears to be a relatively common event. The current definition of treatment success does not take into account the attrition group and thus inflates the relative success of 2-stage exchange arthroplasty.
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•Superhydrophobic cotton-based materials (SCM) were prepared by a simple dipping method.•The SCM was stable under different chemical and physical tests keeping its ...superhydrophobicity.•The compressed SCM showed an outstanding performance for water-in-oil emulsion separation.•The flux is up to 867,500 L m−2h−1 bar−1 and the oil purity of filtrate >99.97% for emulsion separations.
Highly stable emulsified water-in-oil mixtures from industrial processes have severe impact on the environment. As their abundance is increasing worldwide, the methods to effectively separate these emulsified water–oil mixtures have attracted significant interest in recent years. Herein, a durable superhydrophobic cotton-based material (SCM) using poly(vinyl phenol), 1,3-phenylene bisoxazoline, and raw cotton was developed. The as-prepared SCM possesses superhydrophobicity (water contact angle > 150°) and superoleophilicity (oil contact angle < 5°). The SCM has excellent repellence not only toward pure water, but also hot water and corrosive aqueous liquids. The superwetting composite also exhibits durable superhydrophobicity after long-term immersion in organic solvents. Moreover, after the compression process, the superwetting material exhibits a remarkable oil–water separation performance. Very high permeation flux values of up to 10,400 ± 400 L m−2h−1 and 867,500 ± 30,300 L m−2h−1 bar−1 are observed for the surfactant-stabilized water-in-oil emulsion by employing gravity-driven and external pressure filtration, respectively, with excellent efficiencies (oil purity of ≥ 99.97 wt%). The outstanding separation performance for various oils and organic solvents, stability in harsh chemical and physical environments, robustness, and recyclability of the superhydrophobic composite make SCM an excellent candidate for large scale application.
A facile one‐step method has been developed to prepare both superhydrophobic and superoleophilic surfaces of polystyrene (PS) without any chemical modification. A rough film consisting of micro‐bead ...and nano‐fiber mixed structures is formed by spraying a PS solution onto a large area and any type of substrate. The mixed structures with such unique wettability properties can be used in oil/water separation and as oil sorbents.
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