RSC Advances
·
2015
·Vol. 5
·期 19
·14123-14128
·
IF 3.84
Yue Tian,Bining Tian,Cai'e Cui,Ping Huang,Lei Wang,Baojiu Chen
Yb3+/Er3+ codoped spherical Gd2O3 phosphors with different particle sizes were prepared via a urea-assisted homogeneous precipitation process by adjusting the molar ratio of rare earth ions and urea followed by annealing at high temperature. The phases, morphologies, and luminescence properties of the as-prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and upconversion luminescence (UCL) spectra, respectively. The spherical Gd2O3:Yb3+/Er3+ phosphors showed size-dependent upconversion luminescence properties under the excitation of 980 nm-laser. The temperature sensing behavior of spherical Gd2O3:Yb3+/Er3+ phosphors with different particle sizes was studied based on the change of emission intensities from two thermally coupled 2H11/2 and 4S3/2 levels. It is interesting to observe that the sensing sensitivity of the sample increases with decreasing particle size and a sensitivity of 84 × 10−4 K−1 was obtained for the sample with a particle size of 45 nm. Finally, Judd–Ofelt theory was used for explaining and predicting the effect of particle size on sensing sensitivity.
研究领域:
材料科学
·
无机化学
·
光学材料
·
生物医学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2022
·
IF 11.467
Qiaoyu Liu,Xinrui Zhang,Jingwen Xue,Juanjuan Chai,Lu Qin,Jian Guan,Xin Zhang,Shirui Mao
Micro−/nanocarriers due to their significant advantages are widely investigated in pulmonary drug delivery . However, different size carriers have varied drug release rate, concealing the effect of particle size on the fate of drugs in vivo . Therefore, by keeping drug release rate comparable, the objective of this study is to elucidate the influence of particle size itself on drug in vivo fate after intratracheal instillation to mice. Here, using paclitaxel (PTX) as a drug model, 100 nm , 300 nm, 800 nm, and 2500 nm poly(lactide- co -glycolide) (PLGA) particles with the same release rate were prepared. It was demonstrated that the in vivo fate of particles after lung delivery was size-dependent. Consistent with most reports of model particles with neglected release kinetics, the mucus penetration capacity in airtifical mucus decreased with increasing particle size and there is no significant difference between 800 nm and 2500 nm particles. The in vivo airway distribution experiments confirmed the results of the in vitro mucus penetration study, that is, the smaller the particles, the more distributed in the airway. Both in vitro and in vivo macrophage uptake results confirmed that the larger particles were more readily taken up by macrophages. In contrast, the uptake of smaller particles in A549 cells was higher than that of larger particles. Some new findings were disclosed in lung retention, lung absorption and lung targeting. Different from previous reports, this study demonstrated that particles with smaller size had longer lung retention, AUC (0-t) in bronchoalveolar lavage fluid (BALF) of 100 nm particles was 1.6, 1.9, 2.5 times higher than that of 300 nm, 800 nm, and 2500 nm particles and 11.7 times of the PTX solution group. The same trend was observed in lung tissue absorption, the AUC (0-t) in the lavaged lung of 100 nm particles was 1.8, 2.2, 2.8, 8.6 times higher than that of 300 nm, 800 nm, 2500 nm particles and PTX solution groups, respectively. The lung targeting efficiency was particles size independent. In conclusion, the in vivo fate of particles with the same release kinetics after intratracheal instillation is size-dependent, smaller size particles are conducive for lung retention and lung absorption. Overall, our study provided scientific guidance for the rational design of particle based pulmonary drug delivery system.
研究领域:
药剂学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 13
·2538-2546
·
IF 3.545
Min Yang,Guangshe Li,Huixia Li,Junfang Ding,Yan Wang,Liping Li
Manipulating the growth behavior of nano-sized supports is proved to have extremely favorable effects for optimizing the performance of hybrid catalysts. Herein, we investigated the growth kinetics of MgFe2O4 and revealed its size-dependent behavior of Fe occupancies at octahedral and tetrahedral sites and CO oxidation catalytic activity for the first time. MgFe2O4, with particle size ranging from 8.1 nm to 190.0 nm, was prepared via a sol–gel method after post-annealing treatment at a temperature from 400 °C to 1000 °C. The growth of MgFe2O4 nanoparticles obeys the Ostwald ripening mechanism with the quantitative formula D5 = 2.08 × 1014t exp(−122.13/RT). The systematic characteristics show that the redox behavior and O2 activation of hybrid catalysts of Pt/MgFe2O4-T rely on the grain size of MgFe2O4 nanoparticles. The Pt/MgFe2O4-500 catalyst with a support size of 20.6 nm exhibits a remarkable CO oxidation performance due to its abundant chemisorbed oxygen species on the surface and enhanced metal–support interactions among all examined catalysts. Our findings offer significant insight into the size-dependent structure, redox ability and oxygen activation properties of spinel materials and can greatly impact future exploration of novel materials in heterogeneous catalysis.
研究领域:
催化化学
·
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2013
·Vol. 24
·期 6
·1465-1471
·
IF 2.141
Lu Zhong,Rong Kaifeng,Li Ju,Yang Hao,Chen Rong
Dental caries and periodontal disease are widespread diseases for which microorganism infections have been identified as the main etiology. Silver nanoparticles (Ag Nps) were considered as potential control oral bacteria infection agent due to its excellent antimicrobial activity and non acute toxic effects on human cells. In this work, stable Ag Nps with different sizes (~5, 15 and 55 nm mean values) were synthesized by using a simple reduction method or hydrothermal method. The Nps were characterized by powder X-ray diffraction, transmission electron microscopy and UV–vis absorption spectroscopy. The antibacterial activities were evaluated by colony counting assay and growth inhibition curve method, and corresponding minimum inhibitory concentration (MIC) against five anaerobic oral pathogenic bacteria and aerobic bacteria E. coli were determined. The results showed that Ag Nps had apparent antibacterial effects against the anaerobic oral pathogenic bacteria and aerobic bacteria. The MIC values of 5-nm Ag against anaerobic oral pathogenic bacteria A. actinomycetemcomitans , F. nuceatum , S. mitis , S. mutans and S. sanguis were 25, 25, 25, 50 and 50 μg/mL, respectively. The aerobic bacteria were more susceptible to Ag NPs than the anaerobic oral pathogenic bacteria. In the mean time, Ag NPs displayed an obvious size-dependent antibacterial activity against the anaerobic bacteria. The 5-nm Ag presents the highest antibacterial activity. The results of this work indicated a potential application of Ag Nps in the inhibition of oral microorganism infections.
研究领域:
微生物学
·
材料科学
·
口腔医学
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 17
·4099
·
IF 4.2
Bojie Yuan,Shuyue Shangguan,Deqiang Zhao
Silver nanoparticles (AgNPs) with different sizes have been extensively adopted in various commercial products, causing ecological concerns because of the inevitable release of AgNPs into the environment. Hence, understanding the interaction of different-sized AgNPs with environmental substances is important for assessing the environmental risk and fate of AgNPs. In this work, we investigated the impact of anions (NO3−, SO42−, HCO3−/CO32−, Cl−) in aquatic environments on the physicochemical properties and antibacterial activity of different-sized AgNPs (20, 40 and 57 nm). The results showed that the anions whose corresponding silver-based products had lower solubility were more likely to decrease the zeta potential (more negative) of particles, inhibit the dissolution of AgNPs and reduce their antibacterial activity. This should be attributed to the easier generation of coating layers on the surface of AgNPs during the incubation process with such anions. Additionally, the generation of coating layers was also found to be particle-size dependent. The anions were more prone to adsorbing onto larger-sized AgNPs, promoting the formation of coating layers, subsequently resulting in more pronounced variations in the physicochemical properties and antibacterial activity of the larger-sized AgNPs. Therefore, larger-sized AgNPs were more prone to experiencing specific effects from the anions.
研究领域:
环境科学
·
纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Li Yue,Guangci Li,Feng Zhang,Lei Chen,Xuebing Li,Xiang Huang
A series of CoMoO 4 hydrates composed of nanorods have been synthesized with different alcohol–water solvent systems, and the corresponding Co–Mo sulfides are obtained after sequential calcination and sulfurization. The characterization results show the change in solvent system can efficiently adjust the particle size of the Co–Mo precursors, while cannot affect their components and morphologies. Because of the different particle size, the specific surface areas (SSA) of the final Co–Mo sulfides are different. The particles with small size can lead to a high SSA that benefits the exposure and dispersion of active components, and further promote the incorporation of MoS 2 slabs with Co atoms to form “Co–Mo–S” structures on the surface of the sulfides. More “Co–Mo–S” structures would create more coordinative unsaturated sites with high activity in situ during hydrodesulfurization (HDS) reaction, resulting in a higher HDS activity. Among the Co–Mo sulfides, since S-m/w derived from methanol–water system possesses the smallest particle size and the most active sites, it naturally exhibits the highest HDS activity toward dibenzothiophene.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2017
·Vol. 164
·期 12
·H828
·
IF 3.259
Jianhua Zhang,Zongru Li,Qingshan Fu,Yongqiang Xue,Zixiang Cui
Metal nanoparticles electrodes present great difference in electrochemical thermodynamics compared with corresponding bulk electrodes, which depends on the size of nanoparticles that construct the electrodes. However, it remains unclear about the influences of particle size on electrochemical thermodynamics of the electrodes. Herein, the size-dependence of electrochemical thermodynamic functions of metal nanoparticles electrodes was deduced theoretically. Experimentally, taking copper nanoparticles electrode as an example, the standard electrode potentials, the temperature coefficients, and the thermodynamic functions of electrode reaction were obtained by determining the electrode potentials of the electrodes constructed by copper nanoparticles with different sizes at different temperatures. Both the theoretical and the experimental results indicate that with the particle size of metal nanoparticles decreasing, the standard electrode potential and surface tension decreases, while the temperature coefficient, the molar reaction Gibbs energy, enthalpy and entropy increase. Moreover, all these physical quantities are linearly related with the reciprocal of particle radius when the radius exceeds 10 nm. Meanwhile, we also found that the influence regularities of particle size on electrochemical thermodynamic functions of metal nanoparticles electrodes are quite opposite to those of oxide nanoparticles electrodes, which is attributed to the nanoparticles being reactant or product in an electrode reaction.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）