COLLOID AND POLYMER SCIENCE
·
2018
·Vol. 296
·期 3
·575-584
·
IF 1.967
Ren Xiao-Ming,Wei Yu-Han,Zhao Hui,Jiang Tao,Zhang Qunchao,Shi Dean
The shell thickness of core–shell microspheres with a rigid core and soft rubber shell has been accurately controlled through the emulsion polymerization. When the amount of BA monomer and SiO 2 is fixed, the morphology of core–shell microspheres with SiO 2 core ( Φ = 280 nm) and poly (butyl acrylate) (PBA) shell varies along with the emulsifier concentration ( C e ). If C e is lower than a low critical value C el , aggregated micelles with multiple SiO 2 cores are formed. And while C e is higher than an upper critical value C eu , isolated PBA micelles without SiO 2 core appear in the system. For a given amount of BA monomer and SiO 2 core, core–shell particles with single SiO 2 core can only be obtained at C el < C e < C eu . The value of C el or C eu increases with the BA monomer content when the SiO 2 amount is fixed. However, when the number of the emulsifier molecules absorbed onto the surface of the microspheres (Ʃ) is considered, the upper and lower limit Ʃ (Ʃ UC and Ʃ LC ) for the core–shell particles containing single SiO 2 core seems has nothing to do with the BA monomer content. In our system, the value of Ʃ UC is around ~ 3 × 10 6 μm −2 and Ʃ LC is about 1.3 × 10 6 μm −2 . When Ʃ is fixed at 2 × 10 6 μm −2 (Ʃ UC > Ʃ > Ʃ LC ), the rubber shell thicknesses of core–shell particles with single SiO 2 core can vary from 8 to 57 nm along with the weight ratio of BA monomer to SiO 2 that increases from 1:10 to 1:1.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 16
·2755
·
IF 5.719
Yue Xu,Huan Liao,Jing Zhang,Haijun Lu,Xinghua He,Yi Zhang,Zhenbin Wu,Hongyu Wang,Minghua Lu
Recovery phosphorus (P) from P-contaminated wastewater is an efficient and environmentally friendly mean to prevent water pollution and alleviate the P shortage crisis. In this study, oyster shell as calcium sources and peanut shells as carbon sources (mass ratio 1:1) were used to prepare a novel Ca-modified biochar (OBC) via co-pyrolysis, and its potential application after P adsorption as a P biofertilizer for soil was also investigated. The results shown that OBC had a remarkable P adsorption capacity from wastewater in a wide range of pH 4–12. The maximum P adsorption capacity of OBC was about 168.2 mg/g with adsorbent dosage 1 g/L, which was about 27.6 times that of the unmodified biochar. The adsorption isotherm and kinetic data were better described by Langmuir isotherm model (R2> 0.986) and the pseudo second-order model (R2> 0.975), respectively. Characterization analysis of OBC before and after P adsorption by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and specific surface area and porosity analyzer (BET) indicated that the remarkable P adsorption capacity of OBC was mainly ascribed to chemical precipitation, electrostatic adsorption, and hydrogen bonding. Pot experiment results showed that OBC after P adsorption could significantly promote the germination and growth ofSpinacia, which manifested that OBC after P adsorption exhibited a good ability to be reused as P fertilizer for soil.Keywords:phosphorous;oyster shell;peanut shell;biochar;P biofertilizer
研究领域:
环境科学
·
农业科学
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Qingqing Tao,Felipe Nunes Henriquez,Kang Ding,Wai Lun Man,Matthew Y. Lui
The application of ionic liquids and deep eutectic solvents offers a promising opportunity for a more environmentally friendly and straightforward chitin purification process from crustacean shells. Nonetheless, the insufficient recyclability of these ionic solvents poses a challenge to the long-term sustainability of such extraction methods. Thus, there is a strong imperative to focus on employing easily recyclable ionic liquids for chitin isolation, enhancing the overall sustainability of the process. In this investigation, a direct chitin purification procedure that utilized pulping liquors consisting of the superbase-based protic ionic liquid 1,5-diazabicyclo[4.3.0]non-5-enium acetate and its precursor, acetic acid, was developed. It was demonstrated that these pulping liquors were capable of simultaneously deproteinate and demineralize shrimp shells to generate chitins with higher purity, degree of N -acetylation and crystallinity than commercially obtained chitin. More significantly, the pulping liquors can be recycled to their pure form in high quantity by simple distillation under reduced pressure, allowing the reuse of these mixtures, which give chitin of nearly identical purity.
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY LETTERS
·
2022
·Vol. 44
·期 4
·623-633
·
IF 2.716
Hao Zhi-kui,Li Jian-song,Wang Dan-hua,He Fei,Xue Jing-shi,Yin Liang-hong,Zheng Hua-bao
Objectives Shellfish waste is a primary source for making N -acetyl- d -glucosamine. Thus, establishing a high-efficiency and low-cost bioconversion method to produce N -acetyl- d -glucosamine directly from shellfish waste was promising.
Results A mutant C81 was obtained from Chitinolyticbacter meiyuanensis SYBC-H1 via 60 Co-γ irradiation. This mutant C81 showed the highest chitinase activity of 9.8 U/mL that was 85% higher than the parent strain. The mutant C81 exhibted improved antioxidant activities, including total antioxidant capacity, superoxide radical ability, and hydroxyl radical scavenging ability, compared to that of the parent strain. Four out of nine organic solvents increased the chitinase activity by 1.9%, 6.8%, 11.7%, and 15.8%, corresponding to methylbenzene, n-heptane, petroleum ether, and n-hexane, respectively. The biphase system composed of aqueous and hexane presented a five-fold reduction of cell viability compared to the control. Using a continuous fermentation bioconversion process, 4.2 g/L GlcNAc was produced from crayfish shell powder with a yield of 80% of the chitin content. Conclusions This study demonstrated that the mutant C81 is suitable for converting crayfish shell powder into GlcNAc in an aqueous-organic system.
研究领域:
微生物学
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生物化学
·
生物工程
✓ 已验证
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Ping Zhu,Zhongji Gu,Shu Hong,Hailan Lian
For the first time in this study, chitin was solely extracted from lobster shells through a fast, easy and eco-friendly method using deep eutectic solvents (DESs), consisting of mixtures of choline chloride–thiourea (CCT), choline chloride–urea (CCU), choline chloride–glycerol (CCG) and choline chloride–malonic acid (CCMA). The physiochemical properties of the isolated chitins were compared with those of the chemically prepared one and commercial one from shrimp shells. Results showed that CCT, CCU and CCG DESs had no important effect on the elimination of proteins and minerals, while chitin obtained by CCMA DES showed a high purity. The yield (20.63 ± 3.30%) of chitin isolated by CCMA DES was higher than that (16.53 ± 2.35%) of the chemically prepared chitin. The chitin obtained by CCMA DES could be divided into two parts with different crystallinity (67.2% and 80.6%), which also had different thermal stability. Chitin from lobster shells showed porous structure, which is expected to be used for adsorption materials and tissue engineering.
研究领域:
生物化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
·
2021
·
IF 3.9
Yiheng Sun,Guangjian Peng,Yahao Hu,Guijing Dou,Peijian Chen,Taihua Zhang
The indentation of a microcapsule with a spherical indenter is an effective technique to evaluate the elastic properties of microcapsule shells. The spherical indentation of a microcapsule could be modelled as a microsphere with core–shell structure indented by a rigid sphere. Based on the assumption that the deformed pattern of microcapsule is axisymmetric at small indentation displacement, the deformed profile of shell was divided into five regions according to curvature change. The strain energy of shell was then obtained by adding the bending and membrane strain energy of each region together. The strain energy of core is mainly caused by the volume change of core. The microcapsule was treated as a system and its total potential energy is the sum of the strain energy of shell and core minus the work done by external load. Applying the minimum total potential principle, a spherical indentation model that establishes the relationship among the indentation load, the indentation displacement, and the elastic properties and geometric parameters of microcapsules was proposed. Experiments were carried out on PMMA microcapsules with different dimensions to validate the newly proposed spherical indentation model. The average value of elastic moduli obtained by conventional nanoindentation tests on bulk PMMA and the cross-section of PMMA shell was regarded as the nominal value. The average elastic modulus of PMMA shells determined by the proposed model shows a good agreement with the nominal value. Finally, finite element simulations combined with the proposed model were used to predict the indentation behaviors of microcapsules with different dimensions.
研究领域:
材料科学
·
力学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 44
·17988-17997
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IF 5.101
Yi Lu,Jiang-ping Tu,Chang-dong Gu,Xiu-li Wang,Scott X. Mao
Nickel phosphide (Ni2P) hollow spheres were facilely prepared via an organic-phase strategy using nickel(II) acetylacetonate as a metal precursor, trioctylphosphine as a phosphorus source, and octyl ether as solvent. A core/shell-structured Ni2P@C nanocomposite was grown in situ by employing oleylamine and 1-octadecene as capping agent and solvent, respectively, and the hollow Ni2P spheres were homogeneously wrapped by an amorphous carbon shell. The reversible capacity of the Ni2P@C nanocomposite after 50 cycles is 435 mAh g−1 at 0.1 C and 303 mAh g−1 at 0.5 C, respectively, much higher than that of Ni2P (184.2 mAh g−1 at 0.1 C and 123 mAh g−1 at 0.5 C). These improvements are attributed to the carbon shell, which can enhance the conductivity of Ni2P, suppress the aggregation of active particles, and increase their structure stability during cycling.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Penghui Guo,Xiang Gu,Zhaoshuang Li,Xu Xu,Yini Cao,Guoen Yang,Chuntao Kuang,Xingong Li,Yan Qing,Yiqiang Wu
The discharge of heavy metals (HMS) from industrial production has severely damaged the natural environment and human health. To address the challenges posed by heavy metals, a novel almond shell biochar (FeS-CTS@nBC) modified with FeS and chitosan (CTS) was prepared. Scanning electron microscopy and X-ray photoelectron spectroscopy observations revealed a uniform distribution of FeS particles on the biochar. Adsorption thermodynamics experiments showed that the maximum adsorbed amounts of cadmium (Cd), lead (Pb), and chromium (Cr (VI) and Cr (III)) in FeS-CTS@nBC were 85.6, 89.63, 94.2, and 75.62 mg/g, respectively. Results of soil incubation experiments indicated that FeS-CTS@nBC had a desirable immobilization effect on heavy metals, decreasing the bioavailability of Cd, Pb, Cr (VI), and Cr (III) by 29.43 %, 23.93 %, 5.75 % and 5.23 %, respectively. Density functional theory (DFT) calculations, revealed that the oxygen-containing functional groups on the biochar exhibited stronger adsorption capacities for heavy metals. Plant potting experiments indicated that the paddy grew well in the soil remediated with FeS-CTS@nBC. The Cd content in the roots and leaves of the paddy after nBCS2 repair was reduced by 28.01 % and 55.73 %, respectively. Overall, this work provides a promising low-cost method with a simple production process for mitigation of heavy metals from water and soil.
研究领域:
环境科学
·
材料科学
·
植物学
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Xiaoxiang Han,Zhehao Zheng,Chen Yu,Yunli Deng,Qing Ye,Fuge Niu,Qing Chen,Weichun Pan,Yanbo Wang
In order to improve the solubility and antibacterial activity of chitosan and expand its application range, ionized chitosan (ICS) was successfully synthesized from chitosan through methylation and sulfonation reactions in this study. The chemical structures of the polymers were verified by Fourier transform infrared spectroscopy (FTIR) and 1 H NMR, and a series of characterizations of the polymer were carried out by analytical methods such as element analysis (EA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results showed that the water solubility of the modified ICS was significantly improved. The introduction of propyl sulfonic acid groups with particle size decreasing and potential increasing greatly improved the antibacterial activity of chitosan, indicating that the ICS had the potential as a water-soluble antibacterial agent .
研究领域:
材料科学
·
生物医学
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2024
·
IF 0
Ha Nguyen Phuong,Duyen Nguyen Thu,Nguyen Thanh Liem,Vu Anh Doan
Chitosan (CS), with its non-toxic and antibacterial properties, and Poly(ε-caprolactone) (PCL), known for its biodegradability and biocompatibility, are crucial materials in medical applications. This study proposed a solution utilizing electrospinning to manufacture fibers with nanometer-sized core-shell structures from these materials, with CS serving as the fiber core and PCL forming the shell. The influence of manufacturing technology parameters on fiber size and morphology was thoroughly researched and investigated. The solvent system used, Chloroform/Dimethylformamide (DMF), ensured complete solubility, viscosity control, conductivity, and proper solvent evaporation. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) results clearly demonstrated the morphology and internal structure of the nanofibers. The water contact angle (WCA) measurements of the fiber membrane showed almost no significant change over time, indicating strong hydrophobicity of the nanofibers. Additionally, the FTIR spectrum revealed distinct core-shell layers without any blending between them, while DSC analysis showed the thermal properties of fiber membranes. In summary, the electrospinning of nanofibers proved to be stable, producing thin fibers with an average diameter of approximately 400 nm. These findings are expected to significantly enhance the applicability of CS/PCL nanofibers across various fields, including healthcare and smart agriculture.
研究领域:
生物材料
·
医学工程
·
纳米技术
✓ 已验证
DOI
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Pengwei Xie,Peng Liu
Core-shell-corona chitosan-based micelles were designed for the tumor intracellular pH-triggered doxorubicin (DOX) delivery, via a facile in-situ micellization in an aqueous solution of DOX and polyethylene glycol (PEG) and poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) dual-modified chitosan (PEG-g-CS-g-PDPA). The effect of the PDPA modification on the diameter, drug loading-capacity (DLC) and pH-triggered drug release was investigated for the three different polymerization degrees of PDPA (25, 32, and 42) with a similar modification degree of ~22%. The optimized ones, the core-shell-corona DOX/PEG-g-CS-g-PDPA 32 micelles possessed a mean hydrodynamic diameter (D h ) of 211 nm and DLC of 54%, showing an excellent pH-triggered drug release with negligible premature drug leakage in 60 h. Such results indicated that grafting polycation could efficiently improve the performance of the chitosan-based drug delivery system (DDS) for tumor chemotherapy.
研究领域:
药剂学
·
生物材料学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Jing Li,Lu Cao,Bing Li,Haiming Huang,Wei Yu,Cairui Sun,Kehua Long,Brent Young
The activated sludge-based biochar modified by metals performs well for the phosphate adsorbent. The cost of the modification materials and the follow-up treatment of the spent adsorbents are significant limits for the large-scale application of the developed adsorbent. In this study, wasted egg shells and oyster shells, rich in calcium (Ca), were employed to load Ca onto the surface of the activated sludge-based biochar. The results revealed that different forms of Ca on egg shell-modified activated sludge biochar (ESB) and oyster shell modified activated sludge biochar (OSB) induced different adsorption performances. ESB had a greater phosphate adsorption capacity than OSB, where the maximum adsorption capacities were 154.18 mg/g and 129.03 mg/g, respectively. The saturated biochar could slowly release phosphate at different levels of pH; in fact, the phosphate release efficiency of ESB exceeded that of OSB. Economic analysis suggested that the cost of phosphate removal by ESB was $1.13 per kg, and by OSB was $1.22 per kg. The phosphate adsorption using the Ca-loaded biochar revealed good prospects for sustainable development with the advantages of the high efficiency of phosphate removal, low cost and resourceful employment of wastes.
研究领域:
环境科学
·
废水处理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）