RESEARCH ON CHEMICAL INTERMEDIATES
·
2013
·Vol. 40
·期 1
·11-22
·
IF 0.88
Zhi Dongyan,Li Xiangye,Xu Shouhong,Liu Honglai
Microparticles with a core–shell structure were synthesized from SiO 2 particles as core and thermally sensitive hyaluronate–poly( N -isopropylacrylamide) (HA–PNIPAM) hydrogel as shell. The SiO 2 –HA–PNIPAM microparticles were injectable at room temperature and assembled to settle on to biosurfaces. Dynamic light-scattering measurements at different temperatures showed that the temperature-dependence of the diameters ( d ) of SiO 2 –HA–PNIPAM microparticles was reversible. d decreased abruptly when the temperature was increased to their lower critical solution temperature of 307 K. The Mw of HA and the extent of modification by glycidyl methacrylate, D
m , had clear effects on the sizes of the microparticles and their thermal sensitivity. Fluorescein, selected as model drug, was encapsulated in the gel shell to study the dynamics of drug release by this microparticle at body temperature.
研究领域:
生物材料学
·
组织工程
·
药物递送系统
·
纳米医学
·
再生医学
·
高分子科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Shuo Song,Wenzhi Wang,Bingqiang Cao
Halide perovskite quantum dots (PQDs) have been considered to be potential emitting materials for illumination and display applications. Unfortunately, the poor stability (air, water, and thermal) can greatly limit their practical applications. Herein, the mono-dispersed pure CsPbBr 3 PQDs with cubic morphologies are prepared by using a modified hot-injection method, as a control group. Based on this, a new surface activation strategy for preparing single CsPbBr 3 @SiO 2 core-shell PQDs with their initial cubic morphology and optical properties has been developed, using the CsPbBr 3 PQDs as a precursor and choosing the APTES as the surface ligand which can form a Si–O–Si covalent bond with the subsequently added silane to help complete single CsPbBr 3 @SiO 2 PQDs. The average thickness of the coated shell is about 2.3 nm and basically maintains the initial morphology and optical properties of PQDs. The PL intensity of CsPbBr 3 @SiO 2 PQDs dispersed in a mixed solution of toluene and water can retained 35% of the initial value even after 13 h, which are much higher than the pure CsPbBr 3 PQDs (9%). The photo-stability tests (air, water, and thermal stability) indicate that the CsPbBr 3 @SiO 2 PQDs is markedly more stable than that of the CsPbBr 3 PQDs owing to the complete encapsulation of the SiO 2 shell, indicating that the host packaging is an effective way to improve the stability. This work provides a simple and reliable synthesis way to synthesize the single core-shell particles, which can be suitable for other perovskite systems.
研究领域:
材料科学
·
纳米技术
·
光电技术
·
化学
✓ 已验证
DOI
高影响因子
Science of Advanced Materials
·
2022
·Vol. 14
·期 3
·576-580
·
IF 1.067
Tang Si-Lu,Liu Ya-Lin,Li Xu-Ming,Chen Qian-Wen,Chen Heng-Yu,Zhou Ji-Li,Chen Liang,Gu Zi-Yi,Shao Shi-Xing,Qiao Pei-Zhi,Shen Guo-Dong,Yang Bing-Chuan
The core–shell TiO2 nano-layer spheres were synthesized by hydrothermal method without surfactant, using tetraisopropyl titanate, diethylenetriamine and water as the capping agents. The structure of the products was characterized with X-ray diffraction (XRD), transmission
electron microscope (TEM) and scanning electron microscopy (SEM). The possible formation mechanism and electrocatalytic degradation characters of the products were also discussed.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE FORUM
·
2016
·
IF 0
Xu Cheng,Yue Ming Li,Biao Wang,Jian Ming Jiang
In this paper, low-temperature preparation of rice husk char/TiO2 composite was developed by utilizing agriculture waste. nanosized TiO2 particles were successfully loaded to rice husk char by in-situ thermal treatment of impregnated rice husk. The structural characteristics and photocatalytic activities of obtained composites were investigated. The specific surface area of rice husk char was enlarged due to the catalytic effect of loaded TiO2 during thermal treatment. The porous rice husk char matrix combined with nanosized TiO2 particles offered large specific surface area and good photocatalytic property. This low-temperature preparation method provided a promising way to reuse the waste biomass and extended the applications of charcoal.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
Desalination and Water Treatment
·
2016
·
IF 1.272
Chunxia Ding,Daoxin Gong,Peng Yu,Jihai Shao,Mei-E Zhong
Chitosan–montmorillonite bionanocomposite (CTS–MMT) was prepared for removing the herbicide quinclorac (QC) from aqueous solution. The resulting nanocomposites were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore size distribution analysis. The adsorption of QC onto CTS–MMT as a function of adsorbent dosage, pH, temperature, ionic strength, contact time, and initial QC concentration was investigated by conducting batch adsorption experiments. The results showed that CTS–MMT exhibited higher adsorption affinity and higher adsorption capacity towards QC than the unmodified montmorillonite. The adsorption kinetics data of QC onto CTS–MMT were well described by the pseudo-second-order kinetics model. Adsorption isotherms fitted well with the Freundlich isotherm model in the heterogeneous adsorption process. Adsorption thermodynamics study indicated that the adsorption of QC onto CTS–MMT was a spontaneous and endothermic process. The QC molecules on CTS–MMT could hardly be desorbed by water, but could be desorbed by 0.1 mol/L NaOH solution. QC adsorption on CTS–MMT may involve electrostatic attraction, cation–dipole, hydrogen bonding, and van der Waals interactions. The findings of this study suggest that CTS–MMT is a potential adsorbent for quinclorac pollution remediation.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
STAR Protocols
·
2023
·
IF 0
Zhipeng Luo,Jiayun Wang,Yu Pan,Peng Gao,Hua Zhang,Ruzhu Wang
Summary Desiccant-coated heat exchangers provide a practical solution for the efficient removal of moisture from the air. Here, we present a protocol to synthesize an ultra-hygroscopic polymer to develop a LiCl loaded in curdlan hydrogel (LiCl@Cur)-coated heat exchanger for deep dehumidification. We describe steps for preparing the curdlan gel solution, hydrogel, LiCl solution, and LiCl@Cur. We then detail procedures for preparing curdlan-coated and LiCl@Cur-coated heat exchangers. The coated heat exchanger described in this protocol has a maximum dehumidification capacity of 12 g/kg. For complete details on the use and execution of this protocol, please refer to Pan et al. (2023). 1
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
PubMed
KINETICS AND CATALYSIS
·
2020
·Vol. 61
·期 3
·480-485
·
IF 0.934
Zhong S.
Abstract Nanofibers are attractive supporting matrices for catalytically active metallic catalysts. Herein, palladium species were successfully incorporated into the modified chitosan/poly(ethylene oxide)/maleic acid nanofibers by electrospinning. Then, the hybrid nanofibers were thermally cross-linked at elevated temperature to improve stable behavior in solution. X-ray diffraction and transmission electron microscopy characterizations show that the palladium nanoparticles are dispersed uniformly inside the hybrid nanofibers. This novel hybrid nanofiber mat displayed high catalytic activity for the Sonogashira coupling reaction of phenyl acetylene with aromatic iodides under copper free condition with moderate to excellent yields. Moreover, this nanofiber mat could be reused 10 times with little activity loss. Thus, we have proposed a facile way to prepare highly active and stable heterogeneous palladium catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
·
2017
·
IF 2.31
Mazhar Ali Raja,Muhammad Arif,Chao Feng,Shah Zeenat,Chen-Guang Liu
A novel pH-responsive polymer based on amphiphilic N-acetyl histidine and arginine-grafted chitosan was synthesized using N-acetyl histidine as hydrophobic segment and arginine as hydrophilic segment by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-mediated coupling reactions as anticancer drug delivery system for doxorubicin. The structure of the synthesized polymer was confirmed by Fourier transform infrared and 1H nuclear magnetic resonance analysis. Due to self-association behavior, N-acetyl histidine and arginine-grafted chitosan structured nanoparticles with in size range of 204 nm. N-acetyl histidine and arginine-grafted chitosan with different substitution degree of N-acetyl histidine were initially prepared and characterized. The critical micelle concentration decreased with increasing substitution degree of N-acetyl histidine. Furthermore, N-acetyl histidine and arginine-grafted chitosan nanoparticles exhibited an acidic pH-triggered aggregation and disassembling nature. The doxorubicin-encapsulated nanoparticles based on synthesized conjugate (N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles) showed a sustained drug release pattern, which could be hastened under acidic pH conditions but delayed with increasing substitution degree of N-acetyl histidine. Anticancer effects demonstrated that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles could suppress both sensitive and resistant human breast tumor cell line (MCF-7) efficiently in a dose- and time-dependent pattern. Confocal microscopy results evidenced increased cellular uptake and enhanced retention of the synthesized nanoparticles in drug-resistant cells demonstrating better efficacy of nanoparticles over native doxorubicin. These results suggest that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles might be promising carriers for delivery of hydrophobic drug doxorubicin against drug-resistant tumors.
研究领域:
药学
·
生物材料
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
Desalination and Water Treatment
·
2016
·
IF 1.272
Manfeng Li,Zhaomei Wang,Bingjie Li
A cellulose/chitosan hydrogel bead was prepared by extruding and regenerating the blends from ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim]Ac) in ethanol. FT-IR, scanning electron microscopy (SEM) and X-ray powder diffraction techniques were used to prove the successful blending of both natural polymers (cellulose and chitosan). Brunauer–Emmet–Teller surface area and pore diameter analysis showed that the beads were nanoporous with pores measuring from 10 to 20 nm. Batch adsorption experiments demonstrated that the bead had a maximum adsorption capacity of 40 mg/g for congo red (CR) dye removal from aqueous solutions, which was more efficient than the most reported natural biosorbents. The CR adsorption capacity at equilibrium was related to initial CR concentration, dosage of beads and pH values of the CR solution. When the initial concentration of CR was 30 mg/L, and the adsorbent dosage was 2.0 g/L, the equilibrium of adsorption was reached within 115 min with the removal rate of 89.6%. The Langmuir model represented the adsorption isotherm data and the experimental results followed a pseudo-second-order rate model, indicating that intraparticle diffusion dominated the adsorption process. The cellulose/chitosan hydrogel beads can be used as an efficient adsorbent for dye contaminant removal from wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 8
·1-10
·
IF 1.92
Li Luzhong,Wang Zhu,Ma Piming,Bai Huiyu,Dong Weifu,Chen Mingqing
A novel bio-adsorbent, composite hydrogel beads, composed of polyvinyl alcohol (PVA), chitosan (CS) and graphene oxide (GO) was prepared by an instantaneous gelation method. The micromorphology and thermal stability of the PVA/CS/GO hydrogel beads were characterized by scanning electronic microscope (SEM) and thermo gravimetric analysis (TGA) respectively. Adsorption of Cu(II) onto PVA/CS/GO hydrogel beads was investigated with respect to pH, initial concentration, temperature and adsorption time. Adsorption data were well matched by Langmuir isotherm and pseudo-second-order kinetic model at the optimum pH 5.5. The maximum adsorption capacities of PVA/CS/GO hydrogel beads were found to be 162 mg g −1 for Cu(II) at 30 °C, which was much higher than that of PVA/CS hydrogel. Thermodynamic studies indicated that the adsorption was spontaneous and endothermic process in nature. Besides, desorption efficiency and reusability of the adsorbents were assessed on basis of six consecutive adsorption-desorption cycles. Based on these studies, it can be seen that PVA/CS/GO hydrogel beads will be a potential recyclable adsorbent for removal of hazardous metal ions in waste water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Wei Liu,Tao Lin,Xue Zhang,Fuchun Jiang,Xiaoshu Yan,Han Chen
The safety threat posed by Perfluoroalkyl acids (PFAAs) in drinking water is a growing concern. In this study, we loaded chitosan (CS) on granular activated carbon (GAC) to adsorb PFAAs, and we explored the role of nanobubbles in the adsorption process through experiments and density functional theory (DFT) calculations. Compared with GAC, we found that the use of the composite adsorbent (CS/GAC) enhanced the removal rate of perfluorooctanoic acid by 136% with the assistance of nanobubbles. PFAAs with different chain lengths have different adsorption mechanisms owing to surface activity differences. PFAAs with longer C–F chains can be directly enriched with amino groups on the CS or air–water interface on composite adsorbents. Additionally, PFAAs can be enriched with nanobubbles in solution to form nanobubble–PFAA colloids, which are adsorbed by protonated amino groups on CS through electrostatic interactions. We found that PFAAs with shorter C–F chains are less affected by nanobubbles, and DFT calculations indicated that the adsorption of short-chain PFAAs is mainly affected by electrostatic interactions. We also proved that the electrostatic interactions between CS and PFAAs are mainly derived from the abundant protonated amino groups.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
KEY ENGINEERING MATERIALS
·
2015
·
IF 0
Shu Lin Guan,Na Fan,Qi Zhong,Ji Ping Wang
Thermo-responsive microgels with core-shell structure were prepared by free radical emulsion polymerization. The core of microgels was consisted of poly (N-isopropyl acrylamide) (PNIPAM), while the shell was consisted of poly (ethylene glycol) methyl ether methacrylate (POEGMA300). In order to compare the transition behavior of the core-shell microgels with the microgels consisted of one thermo-responsive microgel, PNIPAM and POEGMA300 microgels were prepared. PNIPAM exhibits a lower critical solution temperature (LCST) of 32 °C, and the LCST of POEGMA300 is approximately 63 °C. The thermo-responsive microgel behavior was measured by dynamic light scattering (DLS). It is observed that both of PNIPAM and POEGMA300 microgels show a thermo-responsive ability. The particle size significantly drops when the temperature passes LCST. Moreover the particle size of the thermo-responsive microgels with core (PNIPAM)-shell (POEGMA300) structure shows a linear transition behavior when the temperature is between 50 °C and 70 °C.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）