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In closed kitchens, adequate ventilation is necessary. The kitchen range hood is a particularly essential equipment, and its efficacy depends on its exhaust volume. One of the simplest methods for increasing the exhaust volume is fan speed acceleration, but this increases energy consumption. Therefore, this study focuses on identifying a method for increasing the exhaust volume in a fan and simulating the exhaust of a range hood before and after implementing improvements under the same conditions to evaluate the distribution of harmful gases in a kitchen. The computational fluid dynamics method is applied to a range hood. First, to compare the simulation and experimental values of a range hood, the simulation values were calculated to have a certain degree of accuracy. Next, the verification process comprised of three parts for implementing improvements. The first part involved improving the top of the hood cover to enable smoother discharge of the gas. The second part consisted of improving the bottom of the hood cover moderate the reflux effect of gas flow into the range hood. The third part comprised a simulation of the range hood discharge effect after improvements were made as well as evaluation of the amount of harmful gases remaining in the kitchen.

High-entropy TaNbSiZrCr carbide coatings were deposited on WC substrates by radio-frequency unbalanced magnetron sputtering with C2H2 flow rates ranging from 0 to 23 sccm. The microstructure, mechanical properties, tribological properties and anti-corrosion resistance of the coatings were analyzed in both an as-sputtered condition and an annealed condition. The anti-glass sticking performance of the coatings was additionally investigated by annealing the coatings at 750 °C for 1 h on BK7 glass plates. The results showed that the as-sputtered and annealed coatings with a low carbon content (i.e., C2H2 flow rates lower than 8 sccm) had a high hardness (>34.1 GPa). The as-sputtered sample deposited with the maximum C2H2 flow rate (23 sccm) showed the best tribological properties of all the as-sputtered samples. However, the wear rate of the coating increased by a factor of around 10 times after annealing. The annealed coating nevertheless exhibited the highest corrosion resistance of all the coatings. Finally, the glass sticking results showed that the use of an appropriate C2H2 flow rate (4–12 sccm) was beneficial in enhancing the anti-glass-sticking performance of the coatings.

Multifunctional electrospun (ES) nanofibers prepared from random copolymers of poly{(N-isopropylacrylamide)-co-(stearyl acid)-co-[9,9-dihexylfluorene-2-bipyridine-7-(4-vinylphenyl)]} (poly(NIPAAm-co-SA-co-FBPY) were successfully prepared from the electrospinning technique with a single-capillary spinneret. FBPY demonstrated blue or red shift in emission wavelength and fluorescence quenching when chelating with different metal ions. With appropriate composition of SA in the copolymer, films and nanofibers could maintain their morphology in aqueous solution at different thermal treatments. Polymers in three states, solution, film and nanofiber, were prepared and their effects on sensing ability were investigated. The smooth nanofibers prepared from P2 (with copolymer composition of NIPAAm:SA:FBPY = 93:6:1) demonstrated superior sensitivity as low as 10−5 M in sensing zinc ions as compared to polymer films (10−3 M) due to the high specific surface area of nanofibers. The porous nanofibers of P2 were also manufactured to further enhance sensing performance and showed the best sensitivity (10−6 M) among three states when sensing with zinc ions (sensitivity of polymer solution in THF was about 10−5 M). These nanofibers also exhibit an interesting “on/off” switch behavior with decreasing temperature from 40 to 10 °C due to the hydrophobic–hydrophilic transition of NIPAAm moieties which cause the gradual swelling of nanofibers. These results indicated that the new nanofibers could have potential applications in multifunctional sensory devices.

Stimuli-responsive conjugated rod-coil block copolymers have received extensive attention recently because the stimuli-responsive coils, which undergo structure, shape, and property changes as triggered by external signals. They also take the advantages of conjugated rods, which provide tunable structural control and photophysical properties due to their π–π interaction. This review focuses on the recent progress in stimuli-responsive conjugated rod-coil block copolymers on their synthetic routes, stimuli-induced transitions in morphologies, and numerous applications in different fields. We first provide an overview on synthetic methods to prepare copolymers with two major architectures: linear and hyperbranched copolymers. Moreover, the effects of different stimuli on their morphological transitions and their corresponding photophysical properties are summarized. Finally, the promising applications of these block copolymers based on single or multiple stimuli-responsive systems are discussed and highlighted for “intelligent” sensory device and biomedical systems for theranostics.

For this study, we prepared a new type of drug carrier with the characteristics of stimuli-responsive transition and tumor-specific recognition through the co-assembly of two series of amphiphilic block copolymers, poly(e-caprolactone)- b -poly[triethylene glycol methacrylate- co - N -methacryloyl caproic acid] and poly(e-caprolactone)- b -poly[triethylene glycol methacrylate- co - N -(2-(methacrylamido)ethyl) folatic amide]. The pH-dependent thermal transition and the content of the targeting ligands of the mixed polymeric micelles are well correlated with the chemical structures and compositions of these two copolymers. Doxorubicin-loaded mixed polymeric micelles are stable at body temperature in the neutral condition for prolonged circulation in blood vessels, and demonstrated rapid drug release at acidic pH levels. The cumulative drug release profiles showed a relatively slow release at pH 7.4, and a quick release of 85% in 3 h at pH 5.3. The cytotoxicity tests against FA-positive (HeLa) and FA-negative (HT-29) tumor cell lines suggest that this mixed polymeric micelle system has potential merits as a controlled and targeted drug delivery system.

A series of novel light-emitting copolymers consisted of 9,9-dihexylfluorene (F) and different acceptor segments, including quinoxaline (Q), 2,1,3-benzothiadiazole (BT) and thieno[3,4-b]-pyrazine (TP), were synthesized by the palladium-catalyzed Suzuki coupling reaction. Three fluorene-acceptor alternating copolymers (PFQ, PFBT, PFTP) and six F-TP (PFTP0.5–PFTP35) random copolymers were investigated and compared with the parent polyfluorene (PF). The experimental results suggest that the acceptor strength or content significantly affect the electronic and optoelectronic properties. The optical absorption maxima of the PF, PFQ, PFBT, and PFTP are 368, 416, 470, and 578 nm, respectively, which indicates the significance of intramolecular charge transfer. The electrochemical band gap also shows a similar trend. The incorporation of the acceptor into the PF lowers the LUMO level and thus could improve the electron-accepting ability of the PF. The emission maxima on the photoluminescence (PL) spectra of the PF, PFQ, PFBT, and PFTP films are 424, 493, 540, and 674 nm, which correspond to the color of blue, green, yellow, and red, respectively. It suggests that the full color of emission can be achieved by different acceptors. The significant positive solvatochromism on the PL spectra in different polar solvents suggests the efficient intramolecular charge transfer in PFTP. However, such charge transfer or heavy-atom effect results in fluorescence quenching and thus reduces the PL efficiencies. By random copolymerizing the TP into the PF, the PL efficiency could be improved. A significantly reduction on the PF emission peak with increasing the TP content suggests the energy transfer between the PF and TP segments. Besides, the characteristics on the electroluminescence (EL) devices of ITO/PEDOT:PSS/emissive layer/Ca/Ag suggest that such energy transfer results in the complete quenching of the PF emission at only 1% TP content in the PFTP01. The maximum external quantum efficiency (EQE) of the EL device based on the PFTP01 is superior to that of the PF due to the reduced LUMO level in matching with the Ca. The CIE 1931 coordinates of the PFTP01 based EL device under the condition of maximum EQE is (0.66, 0.31), which is close to the standard red of (0.66, 0.34) demanded by the National Television System Committee (NTSC). The luminescence characteristics based on the prepared polymers depend on the Forster energy transfer or the intramolecular charge transfer, or heavy-atom fluorescence quenching. The present study suggests that the tuning of the electronic and optoelectronic properties could be achieved by incorporating various acceptors or content into the polyfluorenes.