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1.
ACS Appl Mater Interfaces ; 16(15): 19421-19431, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38568871

RESUMEN

The employment of flexible piezoresistive sensors has sparked growing interest within the realm of wearable electronic devices, specifically in the fields of health detection and e-skin. Nevertheless, the advancement of piezoresistive sensors has been impeded by their limited sensitivity and restricted operating ranges. Consequently, it is imperative to fabricate sensors with heightened sensitivity and expanded operating ranges through the utilization of the appropriate methodologies. In this paper, piezoresistive sensors were fabricated utilizing electrospun polyvinylidene fluoride/polyacrylonitrile/polyethylene-polypropylene glycol multilayer fibrous membranes anchored with polypyrrole granules as the sensing layer, while electrospun thermoplastic polyurethane (TPU) fibers were employed as the flexible substrate. The sensitivity of the sensor is investigated by varying the fiber diameter of the sensing layer. The experimental findings reveal that a concentration of 14 wt % in the spinning solution exhibits high sensitivity (996.7 kPa-1) within a wide working range (0-10 kPa). This is attributed to the favorable diameter of the fibers prepared at this concentration, which facilitates the uniform in situ growth of pyrrole. The highly deformable TPU flexible fibers and multilayer sensing layer structure enable different linear responses across a broad pressure range (0-1 MPa). Furthermore, the sensor demonstrates good cyclic stability and can detect human movements under different pressures. These results suggest that the piezoresistive sensor with a wide operating range and high sensitivity has significant potential for future health monitoring and artificial intelligence applications.

2.
J King Saud Univ Comput Inf Sci ; 35(5): 101558, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37251782

RESUMEN

Efficient contact tracing is a crucial step in preventing the spread of COVID-19. However, the current methods rely heavily on manual investigation and truthful reporting by high-risk individuals. Mobile applications and Bluetooth-based contact tracing methods have also been adopted, but privacy concerns and reliance on personal data have limited their effectiveness. To address these challenges, in this paper, a geospatial big data method that combines person reidentification and geospatial information for contact tracing is proposed. The proposed real-time person reidentification model can identify individuals across multiple surveillance cameras, and the surveillance data is fused with geographic information and mapped onto a 3D geospatial model to track movement trajectories. After real-world verification, the proposed method achieves a first accuracy rate of 91.56%, a first-five accuracy rate of 97.70%, and a mean average precision of 78.03% with an inference speed of 13 ms per image. Importantly, the proposed method does not rely on personal information, mobile phones, or wearable devices, avoiding the limitations of existing contact tracing schemes and providing significant implications for public health in the post-COVID-19 era.

3.
Ann Med ; 55(1): 325-334, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-36598136

RESUMEN

INTRODUCTION: Long-term exposure to air pollution is known to be harmful to preterm birth (PTB), but little is known about the short-term effects. This study aims to quantify the short-term effect of particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5), ≤10 µm (PM10) and nitrogen dioxide (NO2) on PTB. MATERIALS AND METHODS: A total of 18,826 singleton PTBs were collected during the study period. Poisson regression model combined with the distributed lag non-linear model was applied to evaluate the short-term effects of PTBs and air pollutants. RESULTS: Maternal exposure to NO2 was significantly associated increased risk of PTB at Lag1 (RR: 1.025, 95%CI: 1.003-1.047). In the moving average model, maternal exposure to NO2 significantly increased the risk of PTB at Lag01 (RR: 1.029, 95%CI: 1.004-1.054). In the cumulative model, maternal exposure to NO2 significant increased the risk of PTB at Cum01 (RR:1.026, 95%CI: 1.002-1.051), Cum02 (RR: 1.030, 95%CI: 1.003-1.059), and Cum03 (RR: 1.033, 95%CI: 1.002-1.066). The effects of PM2.5, PM10 and NO2 on PTB were significant and greater in the cold season than the warm season. CONCLUSIONS: Maternal exposure to NO2, PM2.5 and PM10 before delivery has a significant risk for PTB, particularly in the cold season.Key messagesMaternal exposure to NO2 was significant associated with an increased risk of preterm birth at the day 1 before delivery.Particle matter (PM2.5 and PM10) showed a significant short-term effect on preterm birth in the cold season.The effects of air pollutants on preterm birth was greater in the cold season compared with the warm season.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Nacimiento Prematuro , Femenino , Recién Nacido , Humanos , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/etiología , Dióxido de Nitrógeno/efectos adversos , Dióxido de Nitrógeno/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Material Particulado/efectos adversos , Material Particulado/análisis , China/epidemiología
4.
Front Public Health ; 11: 1282451, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38264240

RESUMEN

Background: Neonatal disorders are facing serious public health challenges. Previous studies were based on limited data sources and had a narrow geographical scope. We aim to understand the trends of alteration in the burden of neonatal disorders from 1990 to 2019 in 204 countries and territories. Methods: Data were investigated from the Global Burden of Disease Study 2019. First, we visualized the burden of neonatal disorders using the number of cases and the age-standardized incidence rate (ASIR), death rate (ASDR), and disability-adjusted life years (ASR-DALYs) from 1990 to 2019. Second, estimated annual percentage changes (EAPCs) were used to evaluate the temporal trends of disease burden during different periods. Finally, the sociodemographic index (SDI) and human development index (HDI) were used to determine whether there exists a correlation between socioeconomic development level, human development level, and potential burden consequences. Results: Overall, in the past 30 years, the ASIR trends have remained relatively steady, whereas the ASDR and ASR-DALYs have declined. However, the burden of neonatal disorders varied greatly in various regions and countries. Among 21 regions, the ASIR trend had the largest increase in Central Latin America (EAPC = 0.42, 95%CI = 0.33-0.50). Conversely, the ASDR and ASR-DALYs experienced the largest decrease in Central Europe (EAPC = -5.10, 95%CI = -5.28 to 4.93) and East Asia (EAPC = -4.07, 95%CI = -4.41 to 3.73), respectively. Among 204 countries, the ASIR (EAPC = 3.35, 95%CI = 3.13-3.56) trend in Greece displayed the most significant increase, while the ASDR (EAPC = 1.26, 95%CI = 1.01-1.50) and ASR-DALYs (EAPC = 1.26, 95%CI = 1.03-1.49) trends in Dominica experienced the most substantial increase. Furthermore, there was a strong correlation between the EAPCs in ASIR, ASDR, ASR-DALYs, and SDI or HDI in 2019, with some exceptions. In addition, countries with elevated levels of HDI experienced a faster increase in ASDR and ASR-DALYs for neonatal disorders. Conclusion: Although the burden of neonatal disorders shows a downward trend from 1990 to 2019, it is still not optimistic. It is necessary to implement a multi-pronged approach to reduce the increasing burden of neonatal disorders.


Asunto(s)
Costo de Enfermedad , Carga Global de Enfermedades , Humanos , Recién Nacido , Europa (Continente) , Grecia , Salud Pública
5.
Front Psychol ; 13: 1026996, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36478941

RESUMEN

Background: Noise exposure has a significant impact on human health. However, the effect of occupational and residential noise on the risk of pregnancy complications was controversial in the literature. This study looked at previous research and performed a meta-analysis to determine how noise exposure during pregnancy affected the risk of pregnancy complications. Methods: Systematic searches were conducted in PubMed, Web of Science, Scopus, Embase, Ovid, and Cochrane, and all relevant studies were included. Two investigators independently evaluated the eligibility of these studies. The risk of bias in each study and the quality and strength of each outcome was evaluated by using the GRADE approach and Navigation Guide. Random effects meta-analysis model was used. Results: The meta-analysis retrieved 1,461 study records and finally included 11 studies. Occupational noise exposure during pregnancy was associated with preeclampsia (RR = 1.07, 95%CI: 1.04, 1.10). Neither occupational nor residential noise exposure was associated with hypertensive disorders of pregnancy (HDP) (RR = 1.10, 95%CI: 0.96, 1.25 and RR = 1.05, 95%CI: 0.98, 1.11) or gestational diabetes mellitus (GDM) (RR = 0.94, 95%CI: 0.88, 1.00 and RR = 1.06, 95%CI: 0.98, 1.16). Further bias analysis showed that the results were reliable. All outcomes were rated as low in quality and inadequate evidence of harmfulness in strength. Conclusions: Occupational noise exposure could increase the risk of preeclampsia, according to the findings. There was no clear evidence of a harmful effect of noise exposure during pregnancy on HDP or GDM.

6.
Front Genet ; 13: 856636, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36159992

RESUMEN

Objective: Microcephaly with pontine and cerebellar hypoplasia (MICPCH) is a rare X-linked dominant genetic disease, and most MICPCHs are ascribed to CASK mutations, while few are revealed in Chinese patients. This study aims to identify the pathogenic mutation in a Chinese proband with MICPCH. Methods: A 3-year-old female Chinese proband with MICPCH and her parents were included. Clinical data were collected from the medical records and recalled by the proband's mother. Whole genome sequencing and Sanger sequencing were used to find the pathogenic mutation of MICPCH. Results: The proband presented with postnatal progressive microcephaly, cerebellar hypoplasia, intellectual disability, motor and language development retardation and limb hypertonia. Genetic analysis indicated that there was a novel compound heterozygote nonsynonymous mutation, c.755T>C(p.Leu252Pro) in exon8 of CASK gene in the proband, but not in her parents. This CASK mutation has not been reported in other databases. Conclusion: This study broadens the mutation spectrum of the CASK gene and is of great value for precise prenatal diagnosis and genetic counseling.

7.
Chemosphere ; 301: 134668, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35460673

RESUMEN

BACKGROUND: Low birth weight has long-term health effects, including neurodevelopmental delays, cardiovascular diseases, and type 2 diabetes, through epigenetic changes and modifications. Numerous studies have identified that PM2.5 is associated with low birth weight. However, the association between PM2.5 and renal function, as well as the mediated effect of renal function on the association between prenatal PM2.5 and birth weight are still under-recognized. METHODS: A total of 8969 singleton live births born in 2015-2019 were included in this study. The inverse distance weighting method was applied to interpolate and calculate the average exposure to PM2.5 during pregnancy for each pregnant woman. The multiple linear regression model was used to shed light on the associations among prenatal PM2.5, birth weight, and renal function. In addition, the mediation analysis was performed to figure out the mediated effect of renal function on the association between prenatal PM2.5 and birth weight, and the proportion of mediated effect = (indirect effect/total effect) × 100%. RESULTS: Per 10 µg/m3 increment of prenatal PM2.5 was associated with 8.98 g (95% CI: -16.94 to -1.02) decrease of birth weight, 0.49 (95% CI: -0.73 to -0.26) ml/min/1.73 m2 decrease of glomerular filtration rate (GFR), 0.03 (95% CI: 0.01-0.05) mmol/L increase of blood urea nitrogen (BUN), and 2.29 (95% CI: 0.86-3.72) µmol/L increase of uric acid (UA) after adjusting for the sociodemographic covariates, disease-related covariates and meteorological factors. Besides, the mediated effects of GFR and BUN on the association between prenatal PM2.5 and birth weight were 5.02% and 14.96%, but there was no significant mediated effect being identified in UA. CONCLUSION: Prenatal PM2.5 is related to reduced birth weight and impaired renal function. Renal function plays a partial role in the association between prenatal PM2.5 and birth weight. Appropriate guidelines should be formulated by the concerned authorities, and adequate efforts should be made to mitigate the detrimental health effects of PM2.5.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Diabetes Mellitus Tipo 2 , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Peso al Nacer , Niño , Femenino , Humanos , Riñón/química , Riñón/fisiología , Exposición Materna/efectos adversos , Nitrógeno , Material Particulado/análisis , Embarazo , Ácido Úrico , Vitaminas
8.
J Diabetes Investig ; 13(7): 1262-1276, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35171528

RESUMEN

AIMS/INTRODUCTION: Sleep problems are important public health concern worldwide. We carried out a meta-analysis to quantitatively evaluate whether sleep duration was associated with pregnancy outcomes, and the associations were modified by important characteristics of studies. MATERIALS AND METHODS: Based on PubMed, Embase and the Cochrane Central Register of Controlled Trials databases, we searched for published literature related to maternal sleep duration and adverse pregnancy outcomes before 30 June 2021. We carried out risk of bias assessment, subgroup analyses and sensitivity analysis. The relative risks or odds ratios with 95% confidence intervals (CI) were used to estimate the pooled effects. RESULTS: A total of 5,246 references were identified through a database search, and 41 studies were included in the study. Pregnant women with short sleep duration had 1.81-fold (95% CI 1.35-2.44, P < 0.001) the risk of developing gestational diabetes mellitus. The association between short sleep duration and the risk of gestational hypertension, cesarean section, low birthweight, preterm birth and small for gestational age were not significant (P > 0.05). Furthermore, long sleep duration was significantly correlated with gestational diabetes mellitus (odds ratio1.24. 95% CI 1.12-1.36, P < 0.001) and CS (odds ratio 1.13. 95% CI 1.04-1.22, P = 0.004), whereas long sleep duration was not linked with gestational hypertension, low birthweight, preterm birth and small for gestational age (P > 0.05). CONCLUSIONS: Short/long sleep duration appeared to be associated with adverse pregnancy outcomes, specifically with an increased risk of gestational diabetes mellitus. Sleep should be systematically screened in the obstetric population.


Asunto(s)
Diabetes Gestacional , Hipertensión Inducida en el Embarazo , Nacimiento Prematuro , Peso al Nacer , Cesárea , Diabetes Gestacional/epidemiología , Femenino , Humanos , Hipertensión Inducida en el Embarazo/epidemiología , Hipertensión Inducida en el Embarazo/etiología , Recién Nacido , Embarazo , Resultado del Embarazo/epidemiología , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/etiología , Sueño
9.
Environ Sci Pollut Res Int ; 29(23): 35193-35203, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35060058

RESUMEN

Anemia has been a public health issue evoking global concern, and the low hemoglobin (Hb) concentration links to adverse pregnancy outcomes. However, the associations of PM2.5 and its constituents with Hb and anemia in pregnant women remain unclear. In this retrospective birth cohort study, 7932 pregnant women who delivered in the First Affiliated Hospital of Xi'an Jiaotong University from 2015 to 2018 were included. The Hb during the third trimester in pregnant women was assessed before delivery. PM2.5 and its constituents (BC, NH4+, NO3-, OM, SO42-, and Dust) during pregnancy were retrieved from the V4.CH.03 product constructed by the Atmospheric Composition Analysis Group. Generalized linear regression model was applied to investigate the effects of PM2.5 and its constituents on Hb and anemia during the third trimester in pregnant women. The means and standard deviations of PM2.5, BC, NH4+, NO3-, OM, SO42-, and Dust were 69.56 (15.24), 10.02 (2.72), 8.11 (1.77), 14.96 (5.42), 15.36 (4.11), 10.08 (1.20), and 10.98 (1.85) µg/m3, respectively. Per IQR increase (µg/m3) of PM2.5, BC, NO3-, and OM linked to - 0.75 (- 1.50, - 0.01), - 0.85 (- 1.65, - 0.04), - 0.79 (- 1.56, - 0.03), and - 0.73 (- 1.44, - 0.03) g/L decrease of Hb during the third trimester in multiparous pregnant women, but not for NH4+, SO42-, Dust, and primiparous pregnant women. PM2.5 and its constituents had no significant association with anemia, except for Dust (OR: 0.90, 95% CI: 0.82, 0.99, per IQR increase) in primiparous pregnant women. Besides, SO42- was of lag effects on Hb and anemia in multiparous pregnant women. Moreover, non-linear associations were found among PM2.5 and its constituents, Hb, and anemia. Therefore, exposure to PM2.5 and some constituents of PM2.5 was associated with reduced Hb level during the third trimester in multiparous pregnant women. Related departments and pregnant women should take targeted actions to eliminate the detrimental effects of PM2.5 and its constituents on pregnancy outcomes.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Anemia , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Anemia/epidemiología , Estudios de Cohortes , Polvo/análisis , Femenino , Hemoglobinas/análisis , Humanos , Material Particulado/análisis , Embarazo , Tercer Trimestre del Embarazo , Mujeres Embarazadas , Estudios Retrospectivos
10.
Sci Total Environ ; 818: 151775, 2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-34808172

RESUMEN

This study explores the effects of prenatal exposure to air pollution on the risk of macrosomia and its window of susceptibility. We conducted a retrospective cohort study utilizing records of birth certificates for all full-term live newborns born in Xi'an city, China from January 1, 2015, to December 31, 2018.Weekly- and trimester-specific exposures of PM2.5, PM10, NO2, and O3 during pregnancy were calculated by inverse distance weighting (IDW) based on their residences. Cox proportional hazard model and distributed lag models (DLMs) were performed to estimate the effects of air pollution exposure during pregnancy on macrosomia risk and its window of susceptibility. In total, 318,323 full-term newborns were identified, including 24,996 (7.8%) cases of macrosomia. An IQR increase in PM2.5 exposure (45.46 µg/m3) from the 33rd until the 37th weeks of gestation was positively associated with an elevated risk of macrosomia, with the strongest effect in the 37th weeks (HR = 1.007, 95%CI: 1.002-1.013). The window of susceptibility for NO2 exposure on macrosomia risk was in the 29th-35th gestational weeks, with the strongest effect in the 34th weeks (IQR = 21.96 µg/m3, HR = 1.006, 95%CI:1.000-1.013). For prenatal exposure to O3, 5th-24th weeks of gestation was identified as susceptible windows for elevated risk of macrosomia, with the strongest associations observed in the 15th weeks (IQR = 80.53 µg/m3, HR = 1.022, 95%CI: 1.011-1.033). However, we did not observe any associations between weekly exposure of PM10 and macrosomia. Our findings imply that the windows of susceptibility to PM2.5 and NO2 exposure on macrosomia are mainly in late pregnancy, whereas the windows of susceptibility to O3 exposure are in early and middle pregnancy.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Efectos Tardíos de la Exposición Prenatal , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Femenino , Macrosomía Fetal/epidemiología , Humanos , Recién Nacido , Exposición Materna/efectos adversos , Material Particulado/efectos adversos , Material Particulado/análisis , Embarazo , Efectos Tardíos de la Exposición Prenatal/epidemiología , Estudios Retrospectivos
11.
Front Nutr ; 9: 1031781, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36618680

RESUMEN

Objective: Anemia is still an unfinished global health problem, and adverse birth weight outcomes have everlasting influences on the health of later life. However, the non-linear connections and breakpoints of maternal hemoglobin with birth weight outcomes are still needed to be further elucidated. We aimed to reveal the non-linear connections between maternal hemoglobin during the third trimester of pregnancy and birth weight, low birth weight (LBW), macrosomia, small for gestational age (SGA), and large for gestational age (LGA) in full-term newborns and elucidate the breakpoints of the connections. Methods: A total of 11,411 singletons, full-term, and live newborns, whose mothers conducted the examination of hemoglobin concentration before delivery, were included in this study. A generalized additive model was used to identify and visualize the non-linear connections between maternal hemoglobin and birth weight outcomes. Piecewise linear regression model was adopted to estimate the breakpoints of the connections and report the non-linear connections in detail. Results: There were inverted "U"-shaped exposure-response connections between maternal hemoglobin concentration and birth weight and the risk of macrosomia. There was an increasing trend of the risk of LBW and a decreased trend of LGA with the increase in maternal hemoglobin concentration. The breakpoints of maternal hemoglobin for birth weight were 100 and 138 g/L, and those for SGA were 97 and 138 g/L. The breakpoints of maternal hemoglobin were 119 g/L for LBW, 105 g/L for macrosomia, and 106 g/L for LGA. When maternal hemoglobin concentration ranged from 100 to 138 g/L, maternal hemoglobin concentration increased per 1 g/L, and birth weight significantly decreased by 2.58 g (95% CI: -3.33, -1.83). When maternal hemoglobin concentration ranged from 97 to 138 g/L, maternal hemoglobin concentration increased per 1 g/L, and the risk of SGA significantly increased by 2% (95% CI: 1%, 3%). When maternal hemoglobin concentration was equal to or lower than 119 g/L, maternal hemoglobin concentration increased per 1 g/L, and the risk of LBW significantly increased by 3% (95% CI: 0%, 5%). When maternal hemoglobin concentration was higher than the breakpoints, the risks of macrosomia (OR = 0.99, 95% CI: 0.98, 0.99) and LGA (OR = 0.99, 95% CI: 0.98, 1.00) declined as the increase of maternal hemoglobin concentration. Conclusions: There were non-linear connections between maternal hemoglobin and birth weight outcomes, and there are breakpoints in the connections. Cost-effective interventions targeting pregnant women in the prevention of abnormal maternal hemoglobin concentration should be taken to reduce the incidence of adverse birth weight outcomes.

12.
J Am Chem Soc ; 143(33): 12935-12942, 2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34387467

RESUMEN

We report the preparation of hexagonal mesoporous silica from single-source giant surfactants constructed via dihydroxyl-functionlized polyhedral oligomeric silsesquioxane (DPOSS) heads and a polystyrene (PS) tail. After thermal annealing, the obtained well-ordered hexagonal hybrid was pyrolyzed to afford well-ordered mesoporous silica. A high porosity (e.g., 581 m2/g) and a uniform and narrow pore size distribution (e.g., 3.3 nm) were achieved. Mesoporous silica in diverse shapes and morphologies were achieved by processing the precursor. When the PS tail length was increased, the pore size expanded accordingly. Moreover, such pyrolyzed, ordered mesoporous silica can help to increase both efficiency and stability of nanocatalysts.

13.
Macromol Rapid Commun ; 41(1): e1900534, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31747084

RESUMEN

Microscopic structures have a significant influence on the properties of ceramics. The development of macromolecular self-assembly has allowed for control over microscopic structures of ceramics to prepare ceramics with diverse compositions and ordered nanostructures. Herein, recent progress in the preparation of ceramics with periodically ordered nanostructures guided by phase-separated macromolecules are reviewed, which can be summarized as a general strategy termed the "macromolecule-guided strategy." Moreover, two different subcategories, namely, the macromolecule-templated method and the macromolecule-precursor method, are illustrated. In the former method, amphiphilic macromolecules are used as templates to guide the assembly of inorganic species into ordered nanostructures, which are subsequently converted into ceramics; in the latter method, amphiphilic macromolecules containing non-volatile elements are used as the single-source precursors for ordered ceramics. It is believed that the unique diversity and tunable features of macromolecular self-assembly might offer unprecedented opportunities in the development of functional ceramics for various applications.


Asunto(s)
Cerámica/química , Sustancias Macromoleculares/química , Nanoestructuras/química , Geles/química , Metales/química , Óxidos/química , Polímeros/química , Porosidad , Silicio/química
14.
ACS Omega ; 3(4): 4688-4694, 2018 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-31458690

RESUMEN

A hierarchically porous zirconia (ZrO2) monolith was successfully fabricated by using bacterial cellulose (BC) as a biotemplate and preceramic polymer as a zirconium resource, via freeze-drying and two-step calcination process. Images of scanning electron microscopy showed that the ZrO2 monolith well-replicated a three-dimensional reticulated structure of pristine BC and possessed good morphology stability till 1100 °C in air. Results of N2 adsorption/desorption and mercury porosimetry analysis revealed the hierarchically porous structure and large specific area (9.7 m2·g-1) of the ZrO2 monolith, respectively. Patterns of X-ray powder diffraction indicated that the monoclinic phase and tetragonal phase coexisted in the ZrO2 monolith with the former as the main phase. In addition, the ZrO2 monolith possessed low bulk density (0.13 g·cm-3) and good mechanical strength. These properties suggest that the as-prepared ZrO2 monolith has a great potential to serve as an ideal catalyst or catalyst support.

15.
Materials (Basel) ; 10(4)2017 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-28772734

RESUMEN

In this study, novel photocatalyst monolith materials were successfully fabricated by a non-solvent induced phase separation (NIPS) technique. By adding a certain amount of ethyl acetate (as non-solvent) into a cellulose/LiCl/N,N-dimethylacetamide (DMAc) solution, and successively adding titanium dioxide (TiO2) nanoparticles (NPs), cellulose/TiO2 composite monoliths with hierarchically porous structures were easily formed. The obtained composite monoliths possessed mesopores, and two kinds of macropores. Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), and Ultraviolet-visible Spectroscopy (UV-Vis) measurements were adopted to characterize the cellulose/TiO2 composite monolith. The cellulose/TiO2 composite monoliths showed high efficiency of photocatalytic activity in the decomposition of methylene blue dye, which was decomposed up to 99% within 60 min under UV light. Moreover, the composite monoliths could retain 90% of the photodegradation efficiency after 10 cycles. The novel NIPS technique has great potential for fabricating recyclable photocatalysts with highly efficiency.

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