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Recent advances in photocatalysis focus on the development of materials with hierarchical structure and on the surface plasmon resonance (SPR) phenomenon exhibited by metal nanoparticles (NPs). In this work, both are combined in a material where size‐controllable Ag‐NPs are uniformly loaded onto the hierarchical microporous and mesoporous and nanocolumnar structures of ZnO, resulting in Ag‐NP/ZnO nanocomposites. The embedded Ag‐NPs slightly decrease the hydrophobicity of fibrous ZnO, improve its wettability, and increase the absorption of formaldehyde (H2CO) onto the photocatalyst, all of this resulting in excellent photodegradation of formaldehyde in aqueous solution. Besides, we found that Ag‐NPs with optimal size not only accelerate the charge transfer to the surface of ZnO, but also strengthen the SPR effect in the intercolumnar channels of fibrous ZnO particles combining with high concentration of photo‐generated radical species. The micro‐to‐mesoporous ZnO is like a nanoarray packed Ag‐NPs. With Ag‐NPs of diameter 2.5 < ? < 6.5 nm, ZnO exhibits the most superior photodegradation rate constant value of 0.0239 min?1 with total formaldehyde removal of 97%. This work presents a new feasible approach involving highly sophisticated Ag‐NP/ZnO architecture combining the SPR effect and hierarchically ordered structures, which results in high photocatalytic activity for formaldehyde photodegradation. 相似文献
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Liulian Li Tienchong Chang 《Acta Mechanica Solida Sinica》2009,22(6):571-583
G-band mode is one of the most important Raman modes of single-walled carbon nanotubes (SWCNTs). The vibrational frequency of the mode can be used to characterize SWC- NTs. However, analytical expression that can link the frequency to the geometrical parameters of a SWCNT is to date not reported. Based on a molecular mechanics model, the analytical solution is obtained for G-band mode frequency of SWCNTs. The result calculated from the present solutions is in good agreement with the existing experimental and numerical data. 相似文献
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Min Zhang Cuicui Ding Liulian Huang Lihui Chen Haiyang Yang 《Cellulose (London, England)》2014,21(5):3311-3322
Collagen/cellulose blended solutions with collagen/cellulose mass ratio (Col/Cel) of 0, 1/40, 1/20, 1/10 and 1/5 were prepared using [Emim]Ac as solvent. The interactions between the two polymers before and after regeneration were investigated. In steady shear flow, all of the experimental viscosity values were greater than those of the estimated values calculated from the log-additivity rule for each sample, suggesting interactions between the two polymers in solutions. All solutions exhibited shear thinning behavior and the flow curves could be described by Cross model. Zero shear viscosity (η 0) versus Col/Cel was examined and a linear increase (from 8.73 to 16.39 Pa·s) can be observed for η 0 as Col/Cel ≤ 1/10, while there was only a slight increase (from 16.39 to 18.42 Pa·s) in η 0 as Col/Cel increased to 1/5. Dynamic rheology results suggested the existence of aggregates in solution with Col/Cel = 1/10. Furthermore, the activation energy of solution was 84.5 kJ mol?1 as Col/Cel = 1/10, higher than that of cellulose solution (44.2 kJ mol?1). Regenerated films were prepared and characterized to trace back the interactions between the two polymers in [Emim]Ac. Fourier transform infrared spectroscopy indicated the hydrogen-bond interaction between collagen and cellulose in films. The denaturation temperature of collagen in films with Col/Cel ≤ 1/10 could be improved, but it was decreased with the increase of collagen content, and finally was reduced to be close to that of collagen as Col/Cel = 1/5. The features of dynamic mechanical analysis for films were indicative of the lack of homogeneity between collagen and cellulose as Col/Cel = 1/5. Atomic force microscopy images further confirmed the phase-separation when Col/Cel = 1/5. 相似文献
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Xiaolin Luo Jing Liu Haisong Wang Liulian Huang Lihui Chen 《Cellulose (London, England)》2014,21(3):1445-1457
The performance of hot-water extraction (HWE) and steam treatment (ST), followed by kraft pulping were compared for production of high purity-grade dissolving pulp from green bamboo. With the same prehydrolysis intensity (represented by the P-factor), the fractionation efficiency of HWE is far lower than that of ST. Because of lower removal of non-cellulosic components, the solid residue from HWE (even at approximately double the prehydrolysis intensity, P-factor = 1,379) required more active alkali (AA) during kraft pulping to obtain a cellulose purity equivalent to that achieved by the ST (P-factor = 756)-kraft process. To reach equivalent hemicellulose removal, HWE required more severe intensity than ST. However, FTIR and SEM characterizations of solid residue confirmed that intensified HWE resulted in significant lignin condensation. Antagonistic effects of hemicellulose removal and lignin condensation extent on subsequent kraft pulping were therefore more apparent in HWE than that in ST. Under the same kraft pulping conditions, lignin condensation from a severely intensified HWE process (P-factor = 2,020) caused greater cellulose yield and viscosity loss than that found for ST. Finally, at a given residual pentosan or lignin content, the cellulose yields from all HWE-kraft pulps were about 3 % lower than those from ST-kraft pulps. Consequently, based on an optimally setup chlorine dioxide bleaching stage, a cellulosic pulp with alpha-cellulose content of 97.6 % and viscosity of 927 mL/g was successfully produced from a ST-kraft pulp (P-factor = 756, AA = 19 %). 相似文献
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Yang Jiawei Zeng Tong Xu Huimin Ni Yonghao Huang Liulian Chen Lihui Hu Hui-Chao 《Chromatographia》2022,85(6):507-517
Chromatographia - This paper aims to improve the signal response in headspace (HS) analysis over than the GC analysis with a classical splitless injection mode, and this was achieved by the... 相似文献
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Xiaojuan Ma Xin Zheng Mingxin Zhang Xuefang Yang Lihui Chen Liulian Huang Shilin Cao 《Cellulose (London, England)》2014,21(6):3865-3870
Electron beam irradiation (EBI) can degrade lignocellulosic materials and thus be used as a pretreatment method for efficient enzymatic hydrolysis. This research is mainly concerned with the degradation of cellulose and hemicelluloses when bamboo chips are exposed to various doses of EBI. The results show that cellulose degradation occurred continuously but without a gradual drop of the crystalline index with irradiation dose ranging from 0 to 50 kGy; meanwhile, no significant changes were observed in the molecular weight of hemicelluloses. An obvious relationship was found between irradiation dose and cellulose degradation, which could be used to control cellulose degradation by adjusting the EBI dose. Furthermore, the difficulty of cellulose depolymerization [G(s)] in bamboo chips by exposure to EBI was calculated as 0.052 µmol/J. 相似文献
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Li Yinan Li Huixin Huang Jin Huang Liulian Chen Lihui Ni Yonghao Zheng Qinghong 《Cellulose (London, England)》2022,29(8):4439-4453
Cellulose - A highly transparent ZnO/cellulose composite membrane with UV sensing and shielding abilities was prepared via a facile blending method. ZnO nanoparticles (ZnO NPs) without additional... 相似文献
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