NANOTECHNOLOGY
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2021
·Vol. 32
·期 45
·455101
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IF 3.874
Xiaojing Yang,Di-Feng Chen,Lin-Song Li,Xue-Jie Zhao,Mei-Xia Zhao
In this study, a nanodrug carrier (mesoporous silica nanoparticle (MSN)-SS-cysteamine hydrochloride (CS)-hyaluronic acid (HA)) for targeted drug delivery was prepared using MSNs, in which HA was used as a targeting ligand and blocking agent to control drug release. Coumarin is a fluorescent molecule that targets mitochondria. Two conjugates (XDS-DJ and 5-FUA-4C-XDS) were synthesized by chemically coupling nitrogen mustard and 5-fluorouracil with coumarin, which was further loaded into MSN-SS-CS-HA nanocarriers. MTT analysis demonstrated that the nanocomposite MSN-SS-CS@5-FUA-4C-XDS/HA displayed stronger cytotoxicity toward HCT-116 cells than HeLa or QSG-7701 cells. Furthermore, MSN-SS-CS@5-FUA-4C-XDS/HA was able to target the mitochondria of HCT-116 cells, causing decreased mitochondrial membrane potential and excessive production of reactive oxygen species. These results indicate that MSN-SS-CS@5-FUA-4C-XDS/HA has the potential to be a nanodrug delivery system for the treatment of colon cancer.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2021
·
IF 5.455
Mengmeng Zhang,Jiaying Lou,Rui Xu,Peng Li,Yunfei Sha,Hui Zhang,Yu Jia,Zhenxia Chen,Da Wu,Yun Ling,Yaming Zhou
Metal-organic frameworks (MOFs) featuring a fcu-type net based on 12-connected [Zr 6 (μ 3 -O) 4 (μ 3 -OH) 4 ] cluster have received considerable interest for the fundamental investigation of structure-property relationships in a wide range of catalytic reactions . In this work, the bipyridine (bpy) chelate group was introduced into the fcu-type framework of UiO-67, giving UiO-67bpy as the catalyst support. Then, FeCl 3 was post-synthetically anchored to the bpy group, resulting into the isolation of FeCl 3 /UiO-67bpy. Catalyzed hydrolysis of 5-hydroxylmethoxyfurfural (HMF) into levulinic acid (LA) was then explored and revealed that it can efficiently and selectively catalytic convert HMF into LA, which is superior to that of FeCl 3 /UiO-67 where FeCl 3 is encapsulated in the cage of UiO-67 and dispersed on the pore surface. The recyclability studies further confirmed the importance of anchored FeCl 3 where there is no significant decrease in catalytic activity as compared with that of FeCl 3 /UiO-67. Taking the detailed textural porosity and catalytic results of isomorphous structures in consideration, our studies revealed that narrowing the pore size with anchored FeCl 3 on the skeleton of the fcu-type Zr-MOF rather than encapsulating FeCl 3 inside the cage is more favored for the rehydration reaction of HMF to LA.
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FUEL
·
2021
·
IF 6.609
Tao Pan,Sida Ge,Mengnan Yu,Yana Ju,Ran Zhang,Pei Wu,Kuanyu Zhou,Zhijie Wu
Zn modified ZSM-5 zeolite supported Ni bifunctional catalysts were prepared by in-situ hydrothermal synthesis (Zn-Ni-ZSM-5), co-impregnation method (Zn-Ni/ZSM-5) as well as combining in-situ hydrothermal synthesis of Zn-ZSM-5 and sequential impregnation of Ni (Ni/Zn-ZSM-5) and used for the selective converting olefin to aromatics applicable for FCC gasoline hydro-upgrading. The Lewis (L) acid sites generated by ZnOH + species and hydrogenation active sites from Ni 0 species were varied with preparation method, in which their locations at the external surface or micropores of zeolite changed the acid properties of catalysts. Comparing to the Zn-Ni/ZSM-5 from the co-impregnation method, direct in-situ hydrothermal method could incorporate Zn and Ni species within zeolite, which makes the strong interaction between the metal species and the framework Al to form medium-strong L acids (ZnOH + /NiOH + ). This leads to the decrease of ratio of Brønsted acid sites to L acid sites (B/L) from 0.40 to 0.12 and the difficulty in reducing of Ni cations to Ni 0 from 57% to 30% Ni 0 percent. Ni/Zn-ZSM-5 sample prepared by incorporating Zn species into micropores and sequential depositing Ni species at the external surface of zeolite possesses a low B/L ratio similar to Zn-Ni-ZSM-5 (0.20 versus 0.12) but a much higher Ni 0 percent (52% versus 30%). Zn-Ni-ZSM-5 shows closer intimacy between Zn and Ni species comparing to Zn-Ni/ZSM-5 and Ni/Zn-ZSM-5. For the 1-hexene aromatization, the formed iso -alkene at acid sites was quickly saturated to iso -alkanes by the adjacent Ni 0 particles over Ni-Zn-ZSM-5 catalyst in hydrogen steam. However, the location of aromatization active sites (ZnOH + , L acid sites) in micropores and hydrogenation active sites (Ni 0 species) on external surface of Ni/Zn-ZSM-5 makes the tandem conversion of n-alkene → iso -alkene → aromatics, rather than the n-alkene → iso -alkene → iso -alkane. Thus, Zn-Ni-ZSM-5 with close intimacy of ZnOH + and Ni 0 particles shows a high iso -alkane selectivity (27.9% iC 4 + ), while Ni/Zn-ZSM-5 exhibits a high aromatics selectivity (39.6 %) in the conversion of 1-hexene in hydrogen steam. Similar results have also found in the conversion of n-heptane. Here, the control of the intimacy of Zn and Ni in ZSM-5 zeolites has been realized to be a good protocol to adjust the selective conversion of olefins/alkanes to aromatics versus iso -alkanes.
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ANALYTICAL CHEMISTRY
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2021
·
IF 6.986
Jing Chen,Shuying Li,Ying Chen,Jiao Yang,Jianbin Dong,Xiaoquan Lu
5-Hydroxytryptamine (5-HT) is an important neurotransmitter, and its content in the human body is of great significance to human health. In this study, an l-cysteine-terminated triangular silver nanoplate loaded on a MXene (two-dimensional transition metal carbide or nitride) (Tri-AgNP/l-Cys/MXene) electrochemical sensor was used to detect 5-HT. As an electrically active amino acid with a sulfhydryl group, l-cysteine (l-Cys) forms a more stable Ag–S bond with silver nanoparticles, which can selectively substitute trisodium citrate (TSC) in TSC-capped triangular silver nanoplates (Tri-Ag-NP/TSC). Due to the good conductivity, biocompatibility, and large surface area, MXenes provide a good platform for loading Tri-AgNP/l-Cys. Under optimized conditions, the concentration range for detecting 5-HT with the sensor is 0.5–150 μM, and the limit of detection (LOD) is 0.08 μM (S/N = 3). For detecting 5-HT in actual serum samples, the sensor also showed a good recovery rate (95.38–102.3%), and the relative standard deviation was 2.2–3.4%.
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Food Chemistry-X
·
2021
·
IF 5.182
Danli Wang,Jingjing Wang,Jiachen Sun,Shaoping Qiu,Bingquan Chu,Ruosi Fang,Ling Li,Jinyan Gong,Fuping Zheng
5- O -Caffeoylquinic acid (5-CQA), also known as chlorogenic acid, exhibits various biological activities. Hence the interest in its property change during processing and extraction has increased. The present work studied the influence of ultrasound on the stability of 5-CQA at different pH (pH 4.69, 7.09, 7.69 and 9.22) in water and 50% methanol-water system. Different parameters including solvent, ultrasonic power, time, temperature, duty cycle, and liquid height were investigated during the treatment. Results indicate that ultrasound accelerated the degradation of 5-CQA. Based on Weibull model, the degradation kinetics were described. The rate constant ( k ) of the degradation increased with the increasing pH, demonstrating the alkali sensitivity of 5-CQA. The isomerization of 5-CQA to 3- and 4- O -caffeoylquinic acid was found at neutral and alkaline conditions, which was further boosted by ultrasound. The stability of 5-CQA was improved by adding epigallocatechin gallate (EGCG) and vitamin C (VC) respectively.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Jiayu Feng,Fei Wang,Chi Wang,Kai Li,Ping Ning,Xin Sun,Lijuan Jia
A series Ce m Cu n O x /HZSM-5 sorbents were introduced to remove PH 3 in low-temperature and low-oxygen environments. The effects of copper loading and cerium doping on the adsorption–oxidation performance of the sorbents were investigated. Experimental results showed that doping with 1 wt% of cerium (Ce 1 Cu 30 O X /HZSM-5) could significantly improve the performance of the sorbent. The PH 3 breakthrough capacity was identified as 114.36 mg(PH 3 )•g sorbent -1 . In addition, after three thermal regeneration cycles, the sorbent still has ideal performance. X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) analyses exhibited that CuO was the main active species, and Ce-doping can increase the chemisorption oxygen on the surface of the sorbent. BET results demonstrated that the introduction of cerium could improve the specific surface area and pore volume of sorbent. Hydrogen temperature-programmed reduction (H 2 -TPR) and scanning electron microscope (SEM-EDS) indicated that cerium species played an important role in uniformly dispersing copper species on the HZSM-5 surface and improving the oxidation performance of sorbent. Moreover, the reaction products and mechanisms were also investigated by XRD, XPS, and in-situ FTIR spectra. The results indicated that the consumption of CuO and the accumulation of phosphorus species (e.g., P, P 2 O 5 , and Cu 3 P) on the surface and inner pores of the sorbent were the primary reasons for the deactivation of the sorbent.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 3
·51493
·
IF 3.125
Haibo Ouyang,Man Zhou,Jie Fei,Xiao Duan,Tian Liu,Bei Zhao,Jian Feng Huang
The metal organic frameworks (MOF-5) with nanoscale porosity and organic–inorganic heterocyclic structure were chemically grafted onto carbon fibers by solvothermal for forming high mechanical interlocking composite architectures and releasing the interfacial forces, so as to obtain carbon fiber reinforced composite with excellent mechanical and tribological properties. With the multi-scale enhancement of MOF-5, the optimized tensile and bending strength of the composite increased by about 177.9% and 81.3%, respectively. Moreover, the friction coefficient was higher and relatively stable under the continuous wet friction condition, as well as the wear rate was reduced by 44.4%. The work suggests that the application of MOFs can be extended to the field of structural composites.
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ACS Catalysis
·
2021
·
IF 13.084
Ting Wang,Yuebing Xu,Yufeng Li,Lei Xin,Bing Liu,Feng Jiang,Xiaohao Liu
Conversion of syngas into aromatics via the Fischer–Tropsch (FT) route provides a promising way to supply the value-added chemicals. However, it is still a great challenge to achieve controllable aromatics selectivity with good stability. Herein, we report the Na-mediated bimetallic Fe–Ni catalyst simply particle mixed with HZSM-5, which can boost the stable and selective production of aromatics from the syngas. In detail, FeNiOx(5:1)-0.41Na exhibits quite stable catalytic activity with notably higher selectivity to light α-olefins (C2=–C4=) compared to α-Fe2O3-0.75Na. Various characterizations suggest that an appropriate addition of Ni with Na substantially regulates iron carbide formation and suppresses carbon deposition owing to the electron donation of Fe to Ni reducing CO adsorption and dissociation. Interestingly, extra Na results in remarkably increased selectivity to C1o–C4o, despite the fact that Na shows the ability to suppress hydrogenation. Both characterizations and density functional theory (DFT) calculations demonstrate that the addition of Na weakens the Fe–Ni interaction and reduces electron transfer from Fe to Ni, which promotes C1o–C4o formation as Ni tends to reflect its intrinsic catalysis. DFT calculations confirm that the adsorbed CH2 species at the Ni–Fe interface prefers to undergo coupling to form C2H4, and the formed C2H4 spontaneously desorbs from the surface, indicating that the formation of lower olefins is favorable and further chain growth is inhibited. This could be attributed to the fact that the accumulated electron at the Ni–Fe interface weakens the binding strength of CH2 and C2H4 species because of electronic repulsion. Furthermore, the effects of FT product distribution on aromatics formation were also investigated. FeMnOx(5:1)-0.40Na produces longer olefin-rich hydrocarbons in C5+ owing to oxygen vacancy-assisted CO dissociation, leading to highly branched monocyclic aromatics and faster HZSM-5 deactivation because of increased coking from the isomerization–hydrocracking of long hydrocarbons. In contrast, FeNiOx(5:1)-0.41Na-HZSM-5 produces major light aromatics about 65.7% including toluene, ethyl-benzene, and xylene in total aromatics with about 98.6% aromatics in the liquid phase, which benefits from the fact that FeNiOx(5:1)-0.41Na makes shorter hydrocarbons in C5+ and/or Ni metal has a strong ability of H2 dissociation to provide atomic H spillover onto HZSM-5. Thus, HZSM-5 also shows improved stability. Note that the mixed catalysts with a high Na content indicate a substantial Na+ migration to increase light α-olefins in the gas phase owing to suppress H-transfer reaction. This study provides deep insights into how to develop stable and selective iron-based catalysts for the production of FT products and its further conversion into value-added light aromatics.
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ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Wen Li,Kuncan Wang,Guowu Zhan,Jiale Huang,Qingbiao Li
Transformation of CO2 with the help of green hydrogen (prepared from renewable energy) into valuable light olefins (C2=–C4=) is a promising route for utilizing the carbon resource in CO2. Currently, most of the reported bifunctional catalysts for CO2 hydrogenation to light olefins follow a methanol-mediated route that adopts SAPO-34 as the zeolite component. Although ZSM-5 has been widely used in the methanol to propylene process using fixed bed reactors due to high shape-selective property and long lifetime, ZSM-5-based bifunctional catalysts have seldomly been used for CO2 hydrogenation to light olefins. Herein, we proposed a novel synthetic strategy for bio-ZSM-5 with mild acid strength and relatively low acid density using the natural rice husk as a template. The bio-ZSM-5 was integrated with ZnZrOx solid solution nanoparticles, and the derived ZnZrOx&bio-ZSM-5 catalysts exhibited a high C2=–C4= selectivity of 64.4% and total C2–C4 selectivity of 94.5%, but relatively low CH4 selectivity (5.5%) and aromatic selectivity (<1%). The post-modified ZnZrOx&bio-ZSM-5 catalysts further enhanced the catalytic stability with less coke deposition and regulated the ethylene to propylene ratio in light olefin distribution. Furthermore, *CHxO was found to be the key intermediate formed on the ZnZrOx surface and was transferred to the Brønsted acid sites in the bio-ZSM-5 for the subsequent conversion to light olefins, as confirmed by in situ DRIFTS and chemical trapping mass spectrometry.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Xiao Zhao,Xuan Shi,Zhongshun Chen,Long Xu,Chengyi Dai,Yazhou Zhang,Xinwen Guo,Dongyuan Yang,Xiaoxun Ma
A series of ZnO-ZrO 2 solid solutions with different Zn contents were synthesized by the urea co-precipitation method, which were coupled with H-ZSM-5 zeolite to form bifunctional catalysts. As a new benzene alkylation reagent, syngas was used instead of methanol to realize the efficient conversion of syngas and benzene into toluene and xylene. A suitable ratio of ZnO-ZrO 2 led to the significant improvement in the catalytic performance, and a suitable amount of acid helped to increase the selectivity of toluene/xylene and reduce the selectivity of the by-products ethylbenzene and C 9 + aromatics. The highest benzene conversion of 89.2% and toluene/xylene selectivity of 88.7% were achieved over 10% ZnO-ZrO 2 &H-ZSM-5 (Si/Al = 23) at a pressure of 3 MPa and a temperature of 450 °C. In addition, the effect of the zeolite framework structure on product distribution was examined. Similar to the molecular dynamics of aromatic hydrocarbons , H-ZSM-5 zeolites comprise 10-membered-ring pores, which are beneficial to the activation of benzene; hence, the conversion of benzene is higher. H-ZSM-35 and H-MOR zeolites exhibited small eight-membered-ring channels, which were not conducive to the passage of benzene; hence, the by-product ethylbenzene exhibits a higher selectivity. The distance between the active centers of the bifunctional catalysts was the main factor affecting the catalytic performance, and the powder mixing method was more conducive to the conversion of syngas and benzene.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2021
·
IF 5.875
Zhimei Xiao,Bo Zhuang,Guoli Zhang,Miao Li,Yiguang Jin
Sonodynamic therapy (SDT) has been tried for cancer treatment; however, sonosensitizers are usually administered by injection, leading to low distribution in the tumor tissue and compromised therapeutic effect, even serious side effect. Here, we combined cationic liposomal hydroxycamptothecin (CLH) and 5-aminolevulinic acid (5-ALA) via intratracheal (i.t.) administration for the chemo-sonodynamic (Chemo-SDT) therapy of metastatic lung cancer. CLH was prepared from HCPT and the lipid mixture of soybean lecithin/cholesterol/octadecylamine with a film method. The optimal pre-incubation time of 5-ALA with tumor cells before ultrasound exposure was 4 h, for sake of sonosensitizer accumulation, i.e., protoporphyrin IX, the metabolite of 5-ALA. In vitro studies showed the higher cytotoxicity of Chemo-SDT compared to the other treatments, including i.t. CLH, intravenous (i.v.) CLH, and SDT alone. The combination of pulmonary delivery and Chemo-SDT showed the highest anticancer effect among the treatments on the metastatic lung tumor-bearing mice, which was judged according to the tumor appearance and pathological sections. The major anticancer mechanism of Chemo-SDT included the improved apoptosis of cancer cells and the enhanced production of reactive oxygen species, and more importantly, the synergy of chemotherapy and SDT. Pulmonary delivery of chemotherapeutics and sonosensitizers is a promising strategy for the treatment of lung cancer.
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ACS Omega
·
2021
·
IF 3.512
Lei Hu,Jiayi Zheng,Qing Li,Shunhui Tao,Xiaojie Zheng,Xiaodong Zhang,Yao Liu,Xiaoqing Lin
5-hydroxymethylfurfural (5-HMF) is a promising high value-added platform chemical, which can be produced from glucose, fructose, or lignocellulosic biomass via catalysis technology. However, the effective separation of 5-HMF from aqueous solution and actual biomass hydrolysate is still challenging because 5-HMF can be further rehydrated into levulinic acid (LA) and formic acid (FA) under acidic conditions. Herein, the adsorption behavior of glucose and 5-HMF and its follow-up products (LA and FA) from aqueous solutions onto polymeric adsorbents modified with various functional groups (XAD-4, XAD7HP, and XAD761 resins) was systematically investigated. The results showed that XAD761 resin exhibited the highest adsorption selectivity (α5-HMF/glucose = 42.42 ± 5.84, α5-HMF/FA = 18.41 ± 0.50, and α5-HMF/LA = 3.01 ± 0.10) and capacity for 5-HMF (106 mg g–1 wet resin). The adsorption equilibrium was better fitted by the Freundlich isotherm model at the studied range of 5-HMF concentrations. The thermodynamic study and activation energy also revealed that the adsorption process of XAD761 resin for 5-HMF was spontaneous, exothermic, and physical. The kinetic regression results revealed that the kinetic data of 5-HMF was accurately followed by the pseudo-second-order kinetic model. In conclusion, the present study revealed that the potential of phenol formaldehyde resin with hydroxyl groups could be used as an adsorbent for aldehyde organic compounds.
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