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1.
Small ; 20(1): e2305287, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37653592

RESUMO

Poor water stability and single luminous color are the major drawbacks of the most phosphors reported. Therefore, it is important to realize multicolor luminescence in a phosphor with single host and single activator as well as moisture resistance. LaF3 :Pr3+ @SiO2 yolk-shell nanospheres are facilely obtained by a designing new technology of a simple and cost-effective electrospray ionization combined with a dicrucible fluorating technique without using protective gas. In addition, tunable photoluminescence, especially white-light emission, is successfully obtained in LaF3 :Pr3+ @SiO2 yolk-shell nanospheres by adjusting Pr3+ ion concentrations, and the luminescence mechanism of Pr3+ ion is advanced. Compared with the counterpart LaF3 :Pr3+ nanospheres, the water stability of LaF3 :Pr3+ @SiO2 yolk-shell nanospheres is improved by 15% after immersion in water for 72 h, and the fluorescence intensity can be maintained at 86% of the initial intensity. Furthermore, by treating the yolk-shell nanospheres with hydrofluoric acid, it is not only demonstrated that the shell-layer is SiO2 but also core-LaF3 :Pr3+ nanospheres are obtained. Particularly, only fluorination procedure among the halogenation can produce such special yolk-shell nanospheres, the formation mechanism of yolk-shell nanospheres is proposed detailedly based on the sound experiments and a corresponding new technology is built. These findings broaden practical applications of LaF3 :Pr3+ @SiO2 yolk-shell nanospheres.

2.
Environ Sci Technol ; 58(27): 12091-12100, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38916160

RESUMO

The widespread ozone (O3) pollution is extremely hazardous to human health and ecosystems. Catalytic decomposition into O2 is the most promising method to eliminate ambient O3, while the fast deactivation of catalysts under humid conditions remains the primary challenge for their application. Herein, we elaborately developed a splendidly active and stable Mn-based catalyst with double hydrophobic protection of active carbon (AC) and CeO2 (CeMn@AC), which possessed abundant interfacial oxygen vacancies and excellent desorption of peroxide intermediates (O22-). Under extremely humid (RH = 90%) conditions and a high space velocity of 1200 L h-1 g-1, the optimized CeMn@AC achieved nearly 100% O3 conversion (140 h) at 5 ppm, showing unprecedented catalytic activity and moisture resistance toward O3 decomposition. In situ DRIFTS and theory calculations confirmed that the exceptional moisture resistance of CeMn@AC was ascribed to the double protection effect of AC and CeO2, which cooperatively prevented the competitive adsorption of H2O molecules and their accumulation on the active sites of MnO2. AC provided a hydrophobic reaction environment, and CeO2 further alleviated moisture deterioration of the MnO2 particles exposed on the catalyst surface via the moisture-resistant oxygen vacancies of MnO2-CeO2 crystal boundaries. This work offers a simple and efficient strategy for designing moisture-resistant materials and facilitates the practical application of the O3 decomposition catalysts in various environments.


Assuntos
Ozônio , Ozônio/química , Catálise , Carbono/química , Compostos de Manganês/química , Cério/química , Óxidos/química
3.
Angew Chem Int Ed Engl ; 63(22): e202403668, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38462892

RESUMO

The electrolyte chemistry is crucially important for promoting the practical application of lithium metal batteries (LMBs). Here, we demonstrate for the first time that 1,3-dimethylimidazolium dimethyl phosphate (DIDP) and trimethylsilyl trifluoroacetate (TMSF) can undergo in situ transesterification in carbonate electrolyte to generate dimethyl trimethylsilyl phosphate (DTMSP) and 1,3-dimethylimidazolium trifluoroacetate (DITFA) as multifunctional additives for LMBs. H2O and HF can be removed by the Si-O group in DTMSP to improve the moisture resistance of electrolyte and the stability of cathode. Furthermore, the dissolution of lithium nitrate (LiNO3) in carbonate electrolyte can be promoted by the trifluoroacetate anion (TFA-) in DITFA, thereby optimizing the solvation structure and transport kinetics of Li+. More importantly, both DTMSP and DITFA tend to preferential redox decomposition due to the low lowest unoccupied molecular orbital (LUMO) and high highest occupied molecular orbital (HOMO). Consequently, a thin and robust layer rich in P/N/Si on the cathode and an inorganic-rich layer (e.g. Li3N/Li3P) on the anode can be constructed and superior electrochemical performances are achieved. This artificial transesterification strategy to introduce favorable additives paves an efficient and ingenious route to high-performance electrolyte for LMBs.

4.
Environ Sci Technol ; 57(46): 17727-17736, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36862670

RESUMO

Ozone (O3) pollution is highly detrimental to human health and the ecosystem due to it being ubiquitous in ambient air and industrial processes. Catalytic decomposition is the most efficient technology for O3 elimination, while the moisture-induced low stability represents the major challenge for its practical applications. Here, activated carbon (AC) supported δ-MnO2 (Mn/AC-A) was facilely synthesized via mild redox in an oxidizing atmosphere to obtain exceptional O3 decomposition capacity. The optimal 5Mn/AC-A achieved nearly 100% of O3 decomposition at a high space velocity (1200 L g-1 h-1) and remained extremely stable under entire humidity conditions. The functionalized AC provided well-designed protection sites to inhibit the accumulation of water on δ-MnO2. Density functional theory (DFT) calculations confirmed that the abundant oxygen vacancies and a low desorption energy of intermediate peroxide (O22-) can significantly boost O3 decomposition activity. Moreover, a kilo-scale 5Mn/AC-A with low cost (∼1.5 $/kg) was used for the O3 decomposition in practical applications, which could quickly decompose O3 pollution to a safety level below 100 µg m-3. This work offers a simple strategy for the development of moisture-resistant and inexpensive catalysts and greatly promotes the practical application of ambient O3 elimination.


Assuntos
Ozônio , Humanos , Óxidos , Carvão Vegetal , Umidade , Compostos de Manganês , Ecossistema , Oxigênio , Catálise
5.
Molecules ; 28(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37299041

RESUMO

Nowadays, Mn4+-activated fluoride red phosphors with excellent luminescence properties have triggered tremendous attentions for enhancing the performance of white light-emitting diodes (WLEDs). Nonetheless, the poor moisture resistance of these phosphors impedes their commercialization. Herein, we proposed the dual strategies of "solid solution design" and "charge compensation" to design K2Nb1-xMoxF7 novel fluoride solid solution system, and synthesized the Mn4+-activated K2Nb1-xMoxF7 (0 ≤ x ≤ 0.15, x represents the mol % of Mo6+ in the initial solution) red phosphors via co-precipitation method. The doping of Mo6+ not only significantly improve the moisture resistance of the K2NbF7: Mn4+ phosphor without any passivation and surface coating, but also effectively enhance the luminescence properties and thermal stability. In particular, the obtained K2Nb1-xMoxF7: Mn4+ (x = 0.05) phosphor possesses the quantum yield of 47.22% and retains 69.95% of its initial emission intensity at 353 K. Notably, the normalized intensity of the red emission peak (627 nm) for the K2Nb1-xMoxF7: Mn4+ (x = 0.05) phosphor is 86.37% of its initial intensity after immersion for 1440 min, prominently higher than that of the K2NbF7: Mn4+ phosphor. Moreover, a high-performance WLED with high CRI of 88 and low CCT of 3979 K is fabricated by combining blue chip (InGaN), yellow phosphor (Y3Al5O12: Ce3+) and the K2Nb1-xMoxF7: Mn4+ (x = 0.05) red phosphor. Our findings convincingly demonstrate that the K2Nb1-xMoxF7: Mn4+ phosphors have a good practical application in WLEDs.


Assuntos
Fluoretos , Nióbio , Luminescência
6.
Compr Rev Food Sci Food Saf ; 20(3): 2596-2625, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33682364

RESUMO

Per- and polyfluoroalkyl substances (PFAS) have been used in food contact paper and paperboard for decades due to their unique ability to provide both moisture and oil/grease resistance. Once thought to be innocuous, it is now clear that long chain PFAS bioaccumulate and are linked to reproductive and developmental abnormalities, suppressed immune response, and tumor formation. Second-generation PFAS have shorter biological half-lives but concerns about health risks from chronic exposure underscore the need for safe substitutes. Waxes and polymer film laminates of polyethylene, poly(ethylene-co-vinyl alcohol), and polyethylene terephthalate are commonly used alternatives. However, such laminates are neither compostable nor recyclable. Lamination with biodegradable polymers, including polyesters, such as polylactic acid (PLA), polybutylene adipate terephthalate, polybutylene succinate, and polyhydroxyalkanoates, are of growing research and commercial interest. PLA films are perhaps the most viable alternative, but performance and compostability are suboptimal. Surface sizings and coatings of starches, chitosan, alginates, micro- and nanofibrilated cellulose, and gelatins provide adequate oil barrier properties but have poor moisture resistance without chemical modification. Plant proteins, including soy, wheat gluten, and corn zein, have been tested as paper coatings with soy being the most commercially important. Internal sizing agents, such as alkyl ketene dimers, alkenyl succinic anhydride, and rosin, improve moisture resistance but are poor oil/grease barriers. The difficulty in finding a viable replacement for PFAS chemicals that is cost-effective, fully biodegradable, and environmentally sound underscores the need for more research to improve barrier properties and process economics in food packaging products.


Assuntos
Quitosana , Poli-Hidroxialcanoatos , Celulose , Embalagem de Alimentos , Polietileno
7.
J Colloid Interface Sci ; 678(Pt C): 977-986, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39326169

RESUMO

Polyimide (PI) aerogels possess significant potential for various applications due to their outstanding mechanics and thermal insulation. However, a major drawback of these aerogels is their susceptibility to moisture, which not only compromises their insulative performance but also leads to an increase in weight. To address this issue, we have developed a moisture-resistance technique by incorporating a long-chain hydrophobic barrier at the ortho position relative to the imide groups to enhance the moisture-resistance of the PI aerogels. This approach involved using a series of diamines with hydroxyl groups strategically located at the ortho position of imide groups as reactants. The resulting PI aerogels demonstrated a significant improvement in water resistance, reducing water-uptake to merely one-tenth of that recorded in unmodified samples. Furthermore, the effectiveness of this hydrophobic modification was validated through molecular dynamics simulations, which indicated a diffusion coefficient of 4.41 × 10-11 m2/s after modification. These findings represent a considerable advancement in developing effective methods for hydrophobic modification of PI aerogels, with potential applications in aerospace, electronic communications, and environmental protection.

8.
Materials (Basel) ; 17(14)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39063792

RESUMO

The utilization of steel slag as an alternative material in asphalt mixtures is considered the solution to the problem of the shortage of natural aggregates. However, asphalt mixtures with steel slag show susceptibility to damage caused by moisture, especially in powder form. Therefore, blast furnace slag powders were used to compound with steel slag powders as fillers to improve the moisture resistance of asphalt mixtures. The characteristics of the steel slag powders and blast furnace slag powders were investigated initially. Subsequently, the adhesion properties of the asphalt mastics with the powders to the aggregates were evaluated. Finally, the moisture resistances of the asphalt mixtures were identified. The results indicate that the steel slag powder exhibited a notable prevalence of surface pores, which had a more uniform size distribution. In contrast, the blast furnace slag powder exhibited a greater average pore size. The larger specific surface area of the steel slag powder was over 30% larger than that of the blast furnace slag powder, and the superior gelling activity of the blast furnace powder enhanced the adhesion property. Both the steel slag powder and blast furnace slag powder were found to enhance the adhesion properties of the asphalt mastics, while the effect of the steel slag powder was more pronounced, the maximum force difference of which exceeded 200 N. The antagonistic effect of the steel slag powder and blast furnace slag powder on the resistance of the adhesive interface to moisture damage was confirmed by the contact angle test. The incorporation of the blast furnace slag powder markedly enhanced the moisture resistances of the asphalt mixtures. The phenomenon of dynamic moisture damage to the asphalt mixtures was more pronounced under the multicycle times, obviously severer than that in a stable water environment. As the dynamic moisture cycles increased, the degree of destruction gradually approached a steady state.

9.
Int J Biol Macromol ; 267(Pt 1): 131402, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38582462

RESUMO

This study investigates how wheat gluten (WG) films in the presence of salicylic acid are influenced by thermal pretreatment. Unlike previous methods conducted at low moisture content, our procedure involves pretreating WG at different temperatures (65 °C, 75 °C, and 85 °C), in a solution with salicylic acid. This pretreatment aims to enhance protein unfolding, thus providing more opportunities for protein-protein interactions during the subsequent solvent casting into films. A significant increase in ß-sheet structures was observed in FTIR spectra of samples pretreated at 75 °C and 85 °C, showing a prominent peak in the range of 1630-1640 cm-1. The pretreatment at 85 °C was found to be effective in improving the water resistivity of the films by up to 247 %. Moreover, it led to a significant enhancement of 151 % in tensile strength and a 45 % increase in the elastic modulus. The reduced solubility observed in films derived from pretreated WG suggests the development of an intricate protein network arising from protein-protein interactions during the pretreatment and film formation. Thermal pretreatment at 85 °C significantly enhances the structural and mechanical properties of WG films, including improved water resistivity, tensile strength, and intricate protein network formation.


Assuntos
Glutens , Temperatura Alta , Ácido Salicílico , Resistência à Tração , Ácido Salicílico/química , Glutens/química , Solubilidade , Água/química , Triticum/química , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Heliyon ; 10(10): e30748, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38774319

RESUMO

The physical and mechanical properties of biopolymers can be improved by heating technologies. In this research, we improved the properties of Polyvinyl alcohol (PVA)/Uncaria gambir extract (UGE) blend films by post-heating method. After post-heating, the blend film exhibited higher resistance to UV light and improved contact angle performance, while water vapor permeability and moisture absorption decreased. The tensile strength and toughness of the PVA/UGE blend film with a post-heating duration of 40 min were 68.8 MPa and 57.7 MPa, respectively, an increase of 131 % and 127 %, compared to films without post-heating. This facile and cost-effective fabrication method, with environmentally friendly properties, can be applied to biodegradable PVA/UGE blend films to achieve desired properties for optical devices or food packaging materials.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38620071

RESUMO

Despite the high efficiencies currently achieved with perovskite solar cells (PSCs), the need to develop stable devices, particularly in humid conditions, still remains. This study presents the synthesis of a novel photo-cross-linkable fullerene-based hole transport material named FT12. For the first time, the photo-cross-linking process is applied to PSCs, resulting in the preparation of photo-cross-linked FT12 (PCL FT12). Regular PSCs based on C60-sandwich architectures were fabricated using FT12 and PCL FT12 as dopant-free hole transport layers (HTLs) and compared to the reference spiro-OMeTAD. The photovoltaic results demonstrate that both FT12 and PCL FT12 significantly outperform pristine spiro-OMeTAD regarding device performance and stability. The comparison between devices based on FT12 and PCL FT12 demonstrates that the photo-cross-linking process enhances device efficiency. This improvement is primarily attributed to enhanced charge extraction, partial oxidation of the HTL, increased hole mobility, and improved layer morphology. PCL FT12-based devices exhibit improved stability compared to FT12 devices, primarily due to the superior moisture resistance achieved through photo-cross-linking.

12.
Artigo em Inglês | MEDLINE | ID: mdl-39376150

RESUMO

The K2SiF6:Mn4+ (KSFM) phosphor featuring efficient ultranarrow red emissions is an outstanding candidate for white light-emitting diode (WLED) applications. However, poor moisture resistance seriously affects its application performance. In this study, a two-step surface reconstruction strategy is proposed to dramatically enhance the moisture resistance of commercially available KSFM phosphors, involving treatment with H2NbF7 and subsequent hydrothermal treatment. The modified KSFM phosphor exhibits a high internal quantum efficiency (IQE) of 98.9% after the two-step surface treatment. Meanwhile, nearly 100% of the initial emission intensity is retained for the modified KSFM phosphor even after aging in high temperature (85 °C) and high relative humidity (85% RH) environments for 6 days, in sharp contrast to only 18.6% retention for the original KSFM phosphor. The relative emission intensity of the modified KSFM remains at 98.9% even after being immersed in water for 6 h. Additionally, the phosphor-converted LED fabricated with the modified KSFM phosphor demonstrated excellent long-term stability, retaining up to 97.9% of initial luminous efficacy after aging under 85 °C and 85% RH conditions for 500 h. The moisture-resistance mechanism is elucidated on the basis of spectroscopic analysis as well as structural and compositional characterization of the phosphor surface layer, which can be attributed to the formation of a robust Mn4+-rare shell with high crystalline quality following this two-step surface treatment. The findings contribute to the performance improvements of KSFM phosphors for industrial applications.

13.
Chemosphere ; 315: 137679, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36586443

RESUMO

The heat desorption of styrene from adsorbents is impracticable owing to its spontaneous polymerization under heating conditions. However, the feature also brings a potential promoting effect on styrene adsorption. Therefore, it is expected to develop the non-regenerative adsorbents with large adsorption capacity by strengthening the polymerization effect. In this work, C-Cl grafted silica gel adsorbents were prepared by introducing (Chloromethyl)dimethylchlorosilane (CMDMCS) and FeCl2 into silica gel. The C-Cl grafted silica gel exhibited excellent styrene adsorption performance, its adsorption amounts for styrene were 4.67 times and 9 times of unmodified silica gel under dry air condition and high humidity condition (RH = 80%), respectively. In addition, the adsorption of styrene on C-Cl grafted silica gel was almost unaffected by the presence of toluene. The characterization of adsorbents after styrene adsorption indicated that the improvement of adsorption capacity of C-Cl grafted silica gel for styrene can be attributed to atom transfer radical polymerization (ATRP) of styrene molecules on modified silica gel during adsorption process.


Assuntos
Estireno , Tolueno , Sílica Gel , Adsorção , Dióxido de Silício
14.
ACS Appl Mater Interfaces ; 15(29): 35459-35468, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37432932

RESUMO

As a clean, sustainable energy source, sound can carry a wealth of information and play a huge role in the Internet of Things era. In recent years, triboelectric acoustic sensors have received increasing attention due to the advantages of self-power supply and high sensitivity. However, the triboelectric charge is susceptible to ambient humidity, which reduces the reliability of the sensor and limits the application scenarios significantly. In this paper, a highly moisture-resistant fluorinated polyimide composited with an amorphous fluoropolymer film was prepared. The charge injection performance, triboelectric performance, and moisture resistance of the composite film were investigated. In addition, we developed a self-powered, highly sensitive, and moisture-resistant porous-structure acoustic sensor based on contact electrification. The detection characteristics of the acoustic sensor are also obtained.

15.
ACS Appl Mater Interfaces ; 15(16): 20252-20265, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37058140

RESUMO

A narrow-band red-light component is critical to establish high color rendition and a wide color gamut of phosphor-converted white-light-emitting diodes (pc-WLEDs). In this sense, Mn4+-doped K2SiF6 fluoride is the most successful material that has been commercialized. As with K2SiF6:Mn4+ phosphors, Mn4+-doped tantalum heptafluoride (K2TaF7:Mn4+) fulfills a similar luminescence behavior and has been brought in a promising narrow-band red phosphor. But the limited brightness and low moisture-resistant performances have inevitably blocked its practical application. Herein, we employed the density functional theory (DFT)-based ab initio estimation approach to quickly identify the proper sensitizer by systematically investigating the electronic-band coupling between the several possible sensitizers (Rb, Hf, Zr, Sn, Nb, and Mo) and the luminescent center (Mn). Combined with experimental results, Mo was demonstrated to be the optimal sensitizer, which resulted in a 60% enhancement of the emission. On the side, the moisture sensitivity has been effectively improved via grafting the hydrophobic octadecyltrimethoxysilane (ODTMS) layer on the phosphor surface. Through employing the K2TaF7:Mn4+,Mo6+@ODTMS composite as a red component, warm WLEDs with good performance were achieved with a correlated color temperature (CCT) of 4352 K, a luminous efficacy (LE) of 90.1 lm/W, and a color rendering index (Ra) of 83.4. In addition, a wide color gamut reaching up to 102.8% of the NTSC 1953 value could be realized. Aging tests at 85 °C and 85% humidity for 120 h on this device manifested that the ODTMS-modified phosphor had much better moisture stability than that of the unmodified one. These studies provided viable tools for optimizing Mn4+ luminescence in fluoride hosts.

16.
Heliyon ; 8(12): e11967, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36478809

RESUMO

The rise in environmental awareness prompted consideration of environment friendly materials. Natural fiber, on the contrary, has a structure that allows it to absorb moisture attributable to its hydrophilicity, which hinders its wide application and leads to poor interfacial bonding with the polymer matrix. Therefore, fiber surface modification is inevitable, which is usually based on using the functional group of some chemicals to replace the hydrophilic hydroxyl group to make it more moisture resistant and ameliorate the boding between fiber and polymer matrix. In this study, injection molded nypa fiber reinforced polypropylene composites were fabricated. Three different chemical modification i.e., mercerization, H2O2 treatment, maleic anhydride polypropylene (MAPP) compatibilizer, were employed. Other parameters on which the properties of the composite depend, i.e., fiber volume (30%), manufacturing process, etc. were kept the same. Field emission scanning electron microscopic (FE-SEM) images were also investigated to verify the result of experiments. Moisture resistance of the composite was also evaluated. The tensile and flexural properties of treated composite were significantly enhanced than the untreated one. The maximum strength was obtained for MAPP treated composite. The chemical treatment has a less impact on the impact strength of the composite. Better moisture resistance was observed for treated fiber composites. This study provides the insight of using chemical treatment for better adhesion between the fiber and the polymer.

17.
ACS Appl Mater Interfaces ; 14(27): 31257-31266, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35776539

RESUMO

Strong and robust stimulations to human skins with low driving voltages under high moisture working conditions are desirable for wearable haptic feedback applications. Here, a soft actuator based on the "air bubble" electret structure is developed to work in high-moisture environments and produce haptic sensations to human skin with low driving voltages. Experimentally, the water soaking and drying process has been conducted repeatedly for the first time and the 20th time to test the antimoisture ability of the actuator as it recovers its output force up 90 and 65% of the initial value, respectively. The threshold voltages for sensible haptic sensations for the fingertip and palm of volunteers have been characterized as 7 and 10 V, respectively. Furthermore, a demonstration example has been designed and conducted in a virtual boxing game to generate the designated haptic sensations according to the gaming conditions with an accuracy of 98% for more than 100 tests. As such, the design principle, performance characteristic, and demonstration example in this work could inspire various applications with improved reliability for wearable haptic devices.


Assuntos
Percepção do Tato , Desenho de Equipamento , Retroalimentação Sensorial , Tecnologia Háptica , Humanos , Reprodutibilidade dos Testes , Tato , Interface Usuário-Computador
18.
Int J Pharm ; 624: 122011, 2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-35820517

RESUMO

Poly-L-lysine (PLL) is a promising candidate for the treatment of pulmonary infection with lower occurrence of drug-resistance due to its unique antibacterial mechanisms. Dry powder inhalations (DPIs) are considered as the first choice for formulating PLL to treat pulmonary infection on account of direct delivery and satisfactory stability. However, hygroscopicity of PLL limited its therapeutic effect on pulmonary infection when PLL developed into DPIs. The hygroscopicity caused two obstacles including the low drug deposition in the lower respiratory tract and undesirable aerosolization performance deterioration. In this study, PLL was co-spray-dried with L-leucine (LL) to achieve moisture-resistance and desirable aerosolization performance. The ratio of PLL and LL was optimized to obtain particles with different morphology, hygroscopicity and aerodynamic properties. The obtained PLL DPIs were suitable for inhalation with a corrugated surface formed by hydrophobic LL. The anti-hygroscopicity, aerosolization performance and rheological properties of P2 DPIs were optimal when PLL:LL = 85:15. The DPIs particles were stable after being stored at high relative humidity (60 ± 5%), and their superiority in treating pulmonary infections was also proved by in vitro and in vivo experiments. The established PLL DPIs were proved to be a feasible and desirable approach to treat pulmonary infections.


Assuntos
Inaladores de Pó Seco , Polilisina , Administração por Inalação , Aerossóis/química , Leucina/química , Tamanho da Partícula , Pós/química
19.
Biosensors (Basel) ; 12(5)2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35624655

RESUMO

We synthesized core-shell-shaped nanocomposites composed of a single-walled carbon nanotube (SWCNT) and heptadecafluorooctanesulfonic acid-doped polypyrrole (C8F-doped-PPy)/phenyllatic acid (PLA), i.e., C8F-doped-PPy/PLA@SWCNT, for detecting acetone gas with high sensitivity and humidity stability. The obtained nanocomposites have the structural features of a sensing material as a C8F-doped-PPy layer surrounding a single-stranded SWCNT, and a PLA layer on the outer surface of the PPy as a specific sensing layer for acetone. PLA was chemically combined with the positively charged PPy backbone and provided the ability to reliably detect acetone gas at concentrations as low as 50 ppb even at 25 °C, which is required for medical diagnoses via human breath analysis. When C8F was contained in the pyrrole monomer in a ratio of 0.1 mol, it was able to stably detect an effective signal in a relative humidity (RH) of 0-80% range.


Assuntos
Nanocompostos , Pirróis , Acetona , Humanos , Umidade , Lactatos , Nanocompostos/química , Poliésteres , Polímeros/química , Pirróis/química
20.
Materials (Basel) ; 15(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35888206

RESUMO

The circular use of resources (i.e., reuse and recycling of materials) aiming for zero waste is also gaining increasing attention in pavement engineering. In this regard, the possible use of waste plastics in asphalt materials is of strategic importance since a considerable amount of plastic waste from construction and demolition waste and municipal solid waste is generated every year. Given this background, this experimental study aimed to investigate the feasibility of recycling waste polyethylene (PE) into asphalt mixtures. For this purpose, the dry addition of plastic shreds was evaluated to overcome the drawbacks observed in a previous interlaboratory research on PE-modified bituminous binder (i.e., instability/inhomogeneity of blend as well as the need for PE grinding). A comparative laboratory study was carried out on dense graded asphalt mixtures containing different amounts of waste plastics (i.e., 0%, 0.25%, and 1.5% by weight of the mixture). The selected asphalt mixes were investigated in terms of workability, linear visco-elastic characteristics, stiffness, strength, resistance to permanent deformation, and moisture sensitivity. Overall, the experimental findings show that the mixes prepared with the dry addition of plastic wastes were able to guarantee almost the same workability and moisture resistance as the reference material while leading to enhanced performance in terms of stiffness and permanent deformation resistance, with better responses for the higher investigated PE dosage.

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