CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Fengxia Wang,Xu Ding,Xiaobo Niu,Xianyi Liu,Wei Wang,Ji Zhang
Although core-shell structure is favored by many applications, preparing it with green way is rarely been reported. Herein, a core-shell structured Cu@Pd-CS nanocomposite is greenly fabricated utilizing a natural chitosan and applied to glucose detection. As-obtained Cu@Pd-CS nanoparticles were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). When applied to glucose detection, the Cu@Pd-CS exhibits good stability, sensitivity and anti-interference. Moreover, it has a good linear relationship in glucose concentrations range of 0.1−1 mM with the sensitivity of 1.53 μA mM −1 cm −2 and 1−10 mM with the sensitivity of 23.00 μA mM −1 cm −2 . This work proves the practicability of building metal-based core-shell structure nanoparticles with green resources and glucose detection application.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Guotai Li,Hao Li
Catalytic transfer hydrogenation (CTH) is regarded as a promising technology for upgrading biomass to fuels and valuable chemicals in the presence of heterogeneous catalysts. In this work, three Ni2P-based catalysts, such as Ni2P@YSS with a yolk–shell structure, Ni2P@SiO2 with a core–shell structure, and Ni2P/SiO2 with a simple surface-loading structure, were prepared using different synthesis strategies, and were used in the CTH of vanillin in an ethanol environment. The Ni2P@YSS catalyst exhibited the highest conversion (85.6%) and a selectivity of 2-methoxy-4-methylphenol of 76.2% at 180 °C for 5 h among a series of Ni2P-based catalysts, which are closely related to the higher specific surface area (462 m2 g–1), acidic site density (2.31 mmol g–1), and stronger metal–support interactions of the Ni2P@YSS catalyst. Besides, transition metals (Zr and La) were introduced to the Ni2P@YSS catalyst to increase the oxygen vacancy and improve the H dissociation ability, thereby enhancing the catalytic performance of the Ni2P-based catalysts.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Yunquan Liu,Huimei Shan,Yanyue Pang,Hongbin Zhan,Chunya Zeng
Iron modified chitosan/coconut shell activated carbon (Fe/CSCC) composite bead is synthesized to remove Cr(VI) and is characterized to reveal the influencing factors and reaction mechanism. Results show that the adsorption capacity ( Q e ) of Cr(VI) increases with the increase of iron loading, contact time ( t ), Cr(VI) initial concentration ( C 0 ), and temperature ( T ), but decreases with the increase of pH, and mass and volume ratio ( m/v ). After 0.1 mol FeCl 3 modification, the removal efficiency of Cr(VI) by Fe/CSCC reaches as high as 97.25 % at pH = 3, m/v = 1.0 g/L, t = 2880 min, C 0 = 25 mg/L, and T = 25 °C. The coexisting ions of SO 4 2− , HPO 4 − , and Ca 2+ lead to the decrease of Q e by 7.82, 5.05, and 5.50 mg/g, respectively, and the inhibition effect increases with their increasing concentrations. Fe/CSCC adsorption for Cr(VI) is an endothermic spontaneous process, and a chemical and monolayer adsorption, which is better fitted to a pseudo-second-order kinetic. The fitted maximum Q e is 64.49 mg/g by using the Langmuir model. Moreover, after five cycles of regeneration, the Q e value only drops about 3.46 mg/g. Characterization analysis of BET, XRD , FTIR , XPS, and SEM-EDS indicates that Cr(VI) is mainly adsorbed by Fe/CSCC through electrostatic attraction and complexation, which is related to the −COOH and − NH 2 groups, and Fe − O groups, respectively.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 7
·3988-3994
·
IF 7.443
Xiang Li,Fangyuan Gai,Buyuan Guan,Ye Zhang,Yunling Liu,Qisheng Huo
Fe@C core–shell particles were successfully synthesized by coating Fe2O3 particles with resorcinol–formaldehyde resins (RFs) and then calcining to make the RFs carbonize, and at the same time to reduce the core to Fe. Furthermore, we designed and synthesized Fe@C yolk–shell particles to increase the number of active sites on the Fe surface. Compared with pure Fe material, the Fe in these particles possesses a high surface area without serious aggregation. Tests to remove 4-chlorophenol suggest that both these kinds of particles can degrade chlorophenol rapidly and thoroughly based on a Fenton-like reaction. Using Fe@C yolk–shell particles, the chlorophenol can be degraded to a concentration below the HPLC detection limit (<0.5 mg l−1) within 12 minutes. The magnetic properties and good stability of Fe@C endow it with promising potential for water treatment.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FERROELECTRICS
·
2018
·
IF 0.728
Hui Zhang,Qi Tang,Lilong Gao,Hua Yuan,Hai-Lin Cong,Bing Yu
ABSTRCTCore-shell structure particles are attracting considerable attention because of their applications in drug delivery and catalysis carrier. In this study, SiO2@SiO2 core-shell structure with tunable shell thickness was successfully prepared by using tetraethoxysilane (TEOS) as the silica source. Monodisperse nonporous silica spheres with a diameter of 1.7 μm were synthesized by a modified Stöber method. An template CTAB was first grafted onto the SiO2 microsphere surface. Then TEOS was hydrolyzed with the addition of ammonia. Finally, superficially porous core-shell SiO2@SiO2 microspheres were obtained through calcination to remove the template.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Qishu Qu,Yi Min,Lihua Zhang,Qin Xu,Yadong Yin
Monodispersed silica spheres with solid core and fibrous shell were successfully synthesized using a biphase reaction. Both the thickness and the pore size of the fibrous shell could be finely tuned by changing the stirring rate during synthesis. When stirring was adjusted from 0 to 800 rpm, the thickness of the shell could be tuned from 13 to 67 nm and the pore size from 5 to 16 nm. By continuously adjusting the stirring rate, fibrous shells with hierarchical pore structure ranged from 10 to 28 nm and thickness up to 200 nm could be obtained in one pot. We demonstrate that fibrous shells with controllable thickness and pore size could be coated on silica cores with diameters from 0.5 to 3 μm while maintaining the monodispersity of the particles. As a result of the unique fibrous structure, the BET surface area could reach ∼233 m2 g–1 even though the shell thickness was less than 150 nm. The core–shell particles were modified with C18, packed, and then used in high-performance liquid chromatography (HPLC) separation, showing separation performance as high as 2.25 × 105 plates m–1 for naphthalene and back pressure as low as 5.8 MPa. These silica microspheres with fibrous shells are expected to have great potential for practical applications in HPLC.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Yuan Li,Yubin Ying,Yaqi Zhou,Yujun Ge,Chunhong Yuan,Chunhua Wu,Yaqin Hu
The goal of the study is to develop a novel pH-indicating intelligent packaging by using purple potato extractions (PPE), chitosan and surface-deacetylated chitin nanofibers (CN). Since the major pH-sensitive pigment of PPE was anthocyanin (24.3 mg/g), whether anthocyanins could be loaded on a solid phase to prevent its color fading was further tested. The results of Fourier transform infrared spectrophotometry (FT-IR) and differential scanning calorimetry (DSC) indicated that PPE was efficiently attached into the chitosan film. Meanwhile, adding CN (0.450%, w/v) into chitosan film could significantly enhance the tensile strength (TS), the water-resistant ability and the roughness of chitosan film. Whereas higher content of CN (0.600%, w/v) did not further improve mechanical properties and CN would distribute unevenly due to aggregation in the films. In addition to pH-indicating ability, CS-CN-PPE exhibited the extraordinary antioxidant activities and this provides another advantage of packaging readily oxidizable substances. Taken together, the current study provided a novel and biocompatible packaging with strengthened mechanical property and intelligent pH indicator.
研究领域:
食品科学
·
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Li Ma,Yilong Yao,Xiong Zhao,Junsheng Hou,Lei huang,Zihan Ding,Xinlan Lu,Jinjia Wei,Nanjing Hao
The uniformity and monodispersity of the chitosan microsphere are essential requirements for its related applications, and the appearance of undesired satellite droplets needs to be avoided. However, preparing monodispersed, uniform, and size-controllable chitosan microspheres is still a significant challenge. In this paper, a droplet-based microfluidic strategy is developed for the chitosan and fluorescent chitosan microsphere synthesis with controllable size and monodispersity. A water-in-oil droplet microfluidic reaction system is formed, and the monodispersed viscous droplet generation one by one in a step T-junction microchannel and solidified microspheres is observed via a chemical cross-reaction. A side microchannel is designed to separate satellite droplets successfully and improve the quality of the product. The effects of flow rates of two phases, phase ratio, and reaction time are investigated experimentally. The stable operating range for viscous droplets is given. The size of the chitosan could be tuned from 50 to 200 μm, and the production rate could reach up to 1.2 mL·h–1. This work not only provides valuable guidance for polymer microsphere synthesis but also helps to understand the microdispersion mechanism of the non-Newton viscous fluid in depth.
研究领域:
生物工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Linfeng Li,Yaoqi Huang,Yuanyuan Li,Xiaomin Cheng
The regulation of the thermal conductivity of thermal energy storage materials has become a primary challenge to expand the range of utilization for different application scenarios. In this study, organic-shell microcapsule (paraffin@melamine formaldehyde) was initially prepared by in situ polymerization, followed by the deposition of anatase TiO 2 on the organic-shell microcapsule using atomic layer deposition (ALD) to form organic-inorganic double-shell microcapsule. The effect of the thickness of the TiO 2 shell on the equivalent thermal conductivity of the microcapsules was investigated by utilizing ALD's precise and controllable characteristics for the coating thickness. The obtained double-shell microcapsules indicated a drop in thermal storage capacity, but a substantial boost in thermal stability. Moreover, the thermal conductivity of microcapsules can be tuned in the range between 0.1837 and 0.7529 W m −1 K −1 within 1500 ALD cycle treatment. Furthermore, the parameters of ALD, such as reaction temperature and exposure time, were varied to obtain an amorphous TiO 2 shell, and the impacts of different crystal form of TiO 2 on the heat transfer properties of microcapsules were concluded by comparison. Double-shell microcapsules exhibited superior mechanical properties compared to single-shell structure. The findings can stimulate significant research interest in broadening the applications of thermal storage microcapsules.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2021
·
IF 7.991
Hao Li,Feng Wang
It is imperative to develop a wound dressing that can effectively treat bacterial infection in the wound location and speed up wound healing. In this study, chitosan (CS) microspheres with a core–shell structure were prepared using high-voltage electrostatic drop technology. The antimicrobial polypeptide (PonG1) and bFGF, were encapsulated in the core of the CS microsphere. The preparation of CS microspheres was studied by changing the parameters. The surface morphology of CS microspheres and the release quantities of PonG1 and bFGF were observed and detected. In vivo experiments were conducted to study the neovascularization and anti-inflammatory abilities of bFGF and PonG1. The repair ability of CS microspheres was evaluated using a rat model of full-thickness skin wound. Both bFGF and PonG1 exhibited slow release from the CS microspheres within 14 days. In vivo experiments showed that CS microspheres containing PonG1 (3 mg/ml) and bFGF (300 μg/ml) had the best neovascularization and anti-inflammatory effects. CS microspheres containing both bFGF and PonG1 had the strongest ability to repair skin wound. CS microspheres with antimicrobial and vascularized functions can be used as dressings for the repair of hard-to-heal wounds.
研究领域:
生物医学工程
·
药剂学
·
伤口愈合
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Zhixiang Ye,Li Lin,Ziyang Tan,Yu-Jia Zeng,Shuangchen Ruan,Jian Ye
Gap-enhanced Raman tags (GERTs) with built-in Raman molecules show excellent surface-enhanced Raman scattering (SERS) performance and great potential for biomedical applications. In this work, we add a silver (Ag) shell to gold (Au) single-shell GERTs (Au@BDT@Au) to form Au-Ag hybrid multi-shell nanoparticles . It is found that this modification enhances the SERS performance of the NPs and that the thickness of the Ag shell is a key factor in determining the enhancement. Double-shell bimetallic GERTs with a Au core, Au shell and exterior 2 nm-thickness silver shell (Au@BDT@Au@BDT@Ag) show the best SERS performance and good photostability. Moreover, we utilize the double-shell bimetallic GERTs to develop a new kind of SERS-based lateral flow immunoassay (LFIA), acheiving limit of detection as low as 0.7 mIU/mL (0.077 ng/mL). We demonstrated a simple way to fabricate sub-100 nm multi-shell bimetallic GERTs for use as SERS probes with strong Raman signals with potential for in vivo and in vitro application as bioimaging and biosensing probes.
研究领域:
生物医学工程
·
纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Ying Ren,Hongguo Xie,Xiaocen Liu,Fan Yang,Weiting Yu,Xiaojun Ma
The goal of this work is to tune the formation and stability of the alginate-chitosan (AC) polyelectrolyte complexes (PECs) and microcapsules. Particularly, we explore the role of the conformation of chitosan on its interaction with alginate to understand the mechanism underpinning their interactions at the molecular level. Reducing the charge density by increasing pH will increase the compactness of chitosan, the values of the enthalpy (H) and stoichiometry (N) of binding between chitosan and alginate. Consequently, chitosan has advantage in being adsorbed on alginate beads to form microcapsules, including the binding rate and binding amount. Though the total heat release remain similar in the range of ionic strength , chitosan diffuses much easier into alginate hydrogels when in higher ionic strength. Increasing pH and ionic strength both help AC microcapsules to have higher stability. The results indicate that the formation and stability of AC microcapsules are related to the rigidity and conformations of chitosan molecules. After increasing acetylation degree (DA) of chitosan, the binding rate of chitosan and mechanical strength of AC microcapsules are both reduced. This work demonstrates the versatility and feasibility of tuning the formation and stability of polysaccharide microcapsules by physical factors and chitosan chemical structures.
研究领域:
生物材料学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）