CHEMOSPHERE
·
2018
·
IF 4.427
Hao Zhu,Wencheng Ma,Hongjun Han,Chunyan Xu,Yuxing Han,Weiwei Ma
Ozonation of pyridine and indole was investigated both in aqueous solution and biologically pretreated coal gasification wastewater (BPCGW). Experimental results showed that the removal of indole was hardly affected by pH value. Direct reaction rate constant of ozone with pyridine increased from 0.18 M −1 s −1 (protonated pyridine) to 3.03 M −1 s −1 (molecular pyridine), and that with molecular indole was 8.6 × 10 5 M −1 s −1 . Seven and five transformation intermediates were observed for pyridine and indole, respectively. Ozonation pathways were proposed as hydroxylation, opening and cleavage of the aromatic ring. It was found that ammonia nitrogen (NH 3 N) increased by 3.3 mg L −1 in ozone process, suggesting the broken of the C N bonds of pyridine, indole and other N-heterocyclic compounds. In terms of biochemical oxygen demand to chemical oxygen demand (BOD 5 /COD), toxicity and resazurin dehydrogenase activity (DHA), the biodegradability was improved after ozone treatment , indicating the possibility of ozone combined with biosystem for the treatment of BPCGW. The results of gas chromatograph and mass spectrometry (GC-MS) indicated that primary products during first 10 min might lead to the obstinate toxicity, which was further proved by US Environmental Protection Agency (US-EPA) test. This study would assist in obtaining a better understanding of the application of ozonation pretreatment in BPCGW.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yingyue Hu,Xinyao Hu,Lu Xue,Baolong Cui,Yi Du
The modulation of crystal surface is one of the important means of photocatalyst modification. BiOBr photocatalyst with exposed (1 1 0) facets was synthesized at room temperature and pressure using CaCO 3 as a directing agent in this experiment. The addition of CaCO 3 not only promoted the exposed facets of BiOBr from (1 0 2) to (1 1 0), but also improved its ability of photocatalytic degradation of pollutants, meanwhile, changed the specific surface area of BiOBr, provided more active sites, and enhanced the adsorption capacity of BiOBr. At the same time, the effects of different alkaline earth metals on the performance of BiOBr photocatalytic materials were compared, it was determined that the degradation rate of RhB of BiOBr photocatalyst reached 97% within 60 min when adding 500 wt% CaCO 3 , and the main active group in the degradation experiment was h + . In conclusion, BiOBr with different main exposed facets was prepared in this paper, and a new idea was provided for alkaline earth metals in the field of photocatalysis.
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
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2023
·
IF 1.9
Ting Hu,Yujun Wang,Jingwei Lin,Zhanyong Wang
Poly(butylene succinate) (PBS), poly(hexamethylene succinate) (PHS) and three kinds of poly(butylene succinate-co-hexamethylene succinate)s (P(BS-co-HS)s) were enzymatically hydrolyzed by Fusarium solani cutinase. The results showed that the characteristics of the enzymatic hydrolysis of these polyesters were mainly affected by crystallinity, thermal properties and the BS/HS ratio. The enzymatic hydrolysis rates of the polyesters are as follows: P(BS-co-HS52) ≈ P(BS-co-HS71) > PHS > P(BS-co-HS32) > PBS. Furthermore, with increasing HS content, both the degree of crystallinity (Xc) and melting temperature (Tm) of the polyesters first decreased and then increased. P(BS-co-HS52) and P(BS-co-HS71) had the lowest Xc and the lowest Tm, thus had the highest hydrolysis rate; this shows that the hydrolysis rate is affected by Xc and Tm. The results also showed that BS/HS ratio could affect the physical properties and degradability of polyesters. Thus, it is possible to prepare polyesters with various physical properties and degradability for different applications by adjusting BS/HS ratio. The crystalline and amorphous regions of the polyesters were both hydrolyzed, during which parts of the crystalline regions were converted into the amorphous regions. Finally, we found that the crystal structure and thermal stability of the polyesters were not affected by the enzymatic hydrolysis.
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2021
·Vol. 79
·期 11
·9717-9740
·
IF 2.87
Wu Guangfeng,Song Xin,Yang Zhihui,Li Yingchun,Zhang Huixuan
Waterborne polyurethane (WPU) prepolymer with acrylate terminal was prepared by using hydroxyethyl acrylate as an end-capping agent. Modified gelatin (mGH) was prepared by grafting vinyl groups which were obtained from hydrolysis and condensation of vinyl trimethoxysilane onto the renewable natural polymer material cold-water fish skin gelatin. Due to the excellent biodegradability and mechanical properties of cold-water fish skin gelatin, mGH was introduced into the WPU backbone by covalent bonding to improve WPU comprehensive property. The vinyl groups in mGH and the acrylate ends in the WPU prepolymer were connected by UV curing to prepare biodegradable and renewable mGH/WPU chemical hybrid materials. The test results showed that the film-forming properties, the water resistance and thermal stability of WPU were improved by covalent bonding. Water contact angle increased from79.6° to 96.5°, and the maximum thermal degradation rate temperature increased from 340 to 400 °C. In addition, incorporation of mGH with high modulus improved the moduli and yield strength of WPU, in which the yield strength increased from 11.3 to 18.2 MPa. The degradation performance of mGH/WPU chemical hybrid materials was also evaluated that the degradation rate reached 68% in 0.6% lipase PBS solution and 56% in soil after 60 days. The study provides a novel polymerization method for preparing high biodegradable decorative coatings and prints of specialty metals, polymer plastics and certain types of woodware as well as medical scaffold materials. Graphical abstract
研究领域:
材料科学
·
高分子化学
·
环境科学
✓ 已验证
DOI
高影响因子
E-POLYMERS
·
2021
·Vol. 21
·期 1
·336-345
·
IF 2.025
Wen-Bo Neng,Wen-Guang Xie,Bo Lu,Zhi-Chao Zhen,Jun-Long Zhao,Ge-Xia Wang,Jun-Hui Ji
A series of novel biodegradable copolyesters named poly(butylene 3-methyl adipate co -terephthalate) (PBA m T) were synthesized from the monomers of 3-methyl adipic acid (AA m ), 1,4-butanediol (BDO), and terephthalic acid (TPA) through a process of esterification and polycondensation. 1 H NMR analysis shows that they are random copolymers whose composition can be well controlled by the feed ratio of monomers. From the results of DSC and XRD, the introduction of methyl group successfully destroys the crystallizability of the PBA m chains, thus making it become a relative soft segment compared to PBA, while these random PBA m T copolymers constructed by soft segment PBA m and rigid segment PBT change from semi-crystalline polymers to nearly amorphous polymers as the feed ratio of A m increases. Especially, mechanical tests reveal that the copolymers show outstanding elasticity and rebound resilience with excellent strength. These thermoplastic copolyester elastomers with good performance by simply introduction of branched methyl group on polybutylene adipate terephthalate (PBAT) copolymer chains may well explore the potential application of biodegradable PBAT-based material.
Graphical abstract
Methyl branched PBA m T possesses excellent elasticity and shows certain degradation performance.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Sugar Tech
·
2020
·Vol. 22
·期 6
·1138-1147
·
IF 1.198
Li Xin,Deng Ligao,Li Yi,Li Kai
Polylactic acid (PLA) is biodegradable and biocompatible, but some of its functional properties limit its commercial application. To improve the properties of PLA without destroying other useful characteristics, a composite film consisting of microcrystalline cellulose (MCC) and PLA was prepared. In this research, MCC was obtained from bagasse bleached pulp by hydrochloric acid hydrolysis. After being modified by a silane coupling agent (KH550), the MCC was used as reinforcement in the PLA matrix. The degradation performance of the composite film was explored using degradation experiments in which the film was buried in soil. According to the single-factor experiments, the best composite formulation was 3% KH550, 20% KH550-MCC and 15% acetyl tributyl citrate. The results showed that the interfacial compatibility of the MCC/PLA composite films was improved after MCC was modified with KH550. This research showed that the addition of MCC can enhance the degradation rate of MCC/PLA composite films.
研究领域:
材料科学
·
生物工程
✓ 已验证
DOI
高影响因子
BIOMACROMOLECULES
·
2025
·
IF 5.4
Dan Li,Youbing Li,Yu Zhang,Yunsheng Xu,Xianming Zhang,Minna Hakkarainen
Production of high-performance polyesters with tailored degradability remains a challenge. Here, a series of poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters were synthesized by varying the isosorbide (IS) content (0–20 mol %) using tetrabutyl titanate (TBT) as the catalyst. By variation of the IS content, the thermal, mechanical, and optical properties of the copolyesters were effectively tailored. As the IS content increased, the Tg was raised from 80 to 101 °C, and the tensile strength from 58.8 to 68.7 MPa. Moreover, excellent transparency was maintained (up to 90% light transmittance). Interestingly, the susceptibility to hydrolytic degradation was significantly enhanced by the incorporation of IS, with PEIT-20 showing approximately 3.5 times higher weight loss compared to PET after 50 days of alkaline degradation in 0.1 M NaOH solution. This outlines an attractive approach for developing high-performance copolyesters with tunable properties and degradation rates, suitable for applications in transparent thermal packaging materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMACROMOLECULES
·
2020
·
IF 6.092
Jin Han,Qinyue Chen,Yupeng Shen,Zhixiong Liu,Xiaoyu Hao,Mingqiang Zhong,Zhengping Zhao,Michael R. Bockstaller
An efficient process for the synthesis of degradable hydrogels containing octa-betaine ester polyhedral oligomeric silsesquioxane (POSS) through efficient thiol–ene and Menschutkin click reactions was developed. The hydrogels exhibited a yield strength of 0.36 MPa and a compressive modulus of 4.38 MPa and displayed excellent flexibility as well as torsion resistance. Antibacterial efficacy of hydrogels (and degradation products) was evaluated using Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Efficacy was found to increase with the concentration of cetyl chloroacetate (CCA) in the hydrogel network, reaching 93% and 99% for Escherichia coli and Staphylococcus aureus, respectively. Degradation of hydrogels was observed in weak alkali conditions (pH = 8) and at physiological conditions (pH = 7.4). The degradation time of the hydrogels could be finely tuned by variation of the CCA content in the hydrogel and environmental stimulus. The tunable degradation behavior under physiological conditions combined with high antibacterial efficacy could render the presented materials interesting for tissue engineering applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Abid Ali,Lina Song,Jiankun Hu,Jingxian Jiang,Qingqing Rao,Muhammad Shoaib,Shah Fahad,Yongjie Cai,Xiaoli Zhan,Fengqiu Chen,Qinghua Zhang
In this work, a degradable polyurethane composed of caprolactone (CL) and L-Lactide (LLA) as soft segments, and 4,4′-methylenebis(cyclohexyl isocyanate) (H 12 MDI) and polytetramethylene ether glycol (PTMEG) as hard segments, was prepared. Hydrolytic degradation experiment revealed that the degradable polyurethane (PU) could be degraded in artificial seawater. It also showed that caprolactone-co-polyurethane (CL-PU) copolymer with higher crystallinity degraded much slower in artificial seawater. However, the introduction of LLA resulted in an increase in the hydrophilicity and reduction in the crystallinity of degradable PU, as demonstrated by the contact angle analysis. The result of the scanning electron microscope showed that the surface of degradable PU renewed under static condition. Moreover, degradable PU was able to be used as a carrier, and it controlled the release rate of 4, 5-dichloro-2-octyl-isothiazolone (DCOIT). The anti-diatom (Navicula incerta) test demonstrated that the (caprolactone-co-L-lactide)-co-polyurethane 4 (CL/LAx-PU4) with DCOIT contents prevented the adhesion of diatom Navicula incerta (88.37% reduction) due to their self-polishing and the release of antifoulants. Therefore, the degradable PU consisted of CL, LLA, and DCOIT could be a durable resin with good antifouling activity for the application in the marine anti-biofouling field.
研究领域:
材料科学
·
海洋生物学
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Zhitao Hu,Xiaohui Cao,Huahua Huang,Yongming Chen
Poly( ε -caprolactone) (PCL) has been one of the most important biomaterials, but its instinct hydrophobicity and slow biodegradation limit its broad applications. Herein, copolymerization of CL and a hydrophilic macrolactone, 2-oxo-15-crown-5 ether (O15C), was achieved through ring opening polymerization catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) using benzyl alcohol as the initiator at room temperature . A series of poly(CL- co -O15C) copolymers with different O15C contents were prepared by simply tuning the feeding ratio of [CL]/[O15C]. They showed molecular weights ranging from 11.0 to 20.6 kg mol −1 , and polydispersity index between 1.4 and 1.6, characterized by SEC (Size Exclusion Chromatography). Analysis of 1 H NMR indicated that the copolymers belong to a random copolymer structure. The introduction of O15C had a significant influence on thermal stability, hydrophilicity and degradability of the copolymers. With increasing the O15C content, the crystalline ability of PCL segment among the copolymers reduced, while the hydrophilic property was improved obviously. Through hydrolysis experiment, the poly(CL- co -O15C) with O15C content of 38 mol% exhibited a much faster degradable rate than that of the copolymer with O15C content of 10 mol%. Therefore, copolymerization of CL with a crown ether monomer via organic catalyst mediated ROP will be a feasible strategy for modification of polyester materials.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
FLOW MEASUREMENT AND INSTRUMENTATION
·
2022
·
IF 2.42
Jiahui Zhang,Jingquan Luo,Yiwei Wang,Bo Dong,Zhen Xu,Lin Wang,Aixian Liu,Xuqiang Guo
Hydrodynamic cavitation (HC) commonly occurs within industrial pipelines and its unsteady flow characteristics are of great significance for energy conservation and efficiency improvement. This study investigates the effects of methanol concentration (0–20 wt%) on the cavitating flow characteristics and the degradation of Rhodamine B (RhB) under operating conditions of a 0.7 MPa pressure drop, temperature of 30 °C, 200 passes through a venturi reactor, and an initial RhB concentration of 40 μmol/L. The transient cavitation behavior was monitored using a high-speed camera. The cavitation images show that the presence of methanol generates more stable bubbles, which results in less violent bubble collapse. The pressure pulsation and vibration induced by cavitation flow were synchronously measured using high-frequency pressure and acceleration sensors. The spectral analyses of the pressure pulsation indicate that methanol has no effect on the dominant frequency (∼5.5 Hz) at different positions, and the amplitude initially increases with increasing methanol concentration and then stabilizes. The pressure pulsation intensity increases due to the increased vapor pressure of the solution. The vibration spectral analyses show that methanol has little effect on the peak frequencies, which occur near 4.0 kHz and 14.3 kHz of the low and high-frequency bands, respectively, whereas the peak amplitude decreases with increasing methanol concentration. The per-pass degradation model of RhB in methanol solution considering pyrolysis of methanol was verified for the first time and show to adequately describe the experimental data. The degradation percentage and per-pass degradation factor decrease with increasing methanol concentration. The reduced surface tension of the solution prolongs the bubble lifespan and prevents bubble coalescence , thus weakening the vibration and degradation performance . The results provide important insight for cavitation applications and degradation modeling of mixed solutions.
研究领域:
流体力学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Xiao-Chi Feng,Zi-Jie Xiao,Hong-Tao Shi,Bai-Qin Zhou,Yong-Mei Wang,Hui-Zhong Chi,Xiao-Hang Kou,Nan-Qi Ren
Current research has widely applied heteroatom doping for the promotion of catalyst activity in peroxymonosulfate (PMS) systems; however, the relationship between heteroatom doping and stimulated activation mechanism transformation is not fully understood. Herein, we introduce nitrogen and sulfur doping into a Co@rGO material for PMS activation to degrade tetracycline (TC) and systematically investigate how heteroatom doping transformed the activation mechanism of the original Co@rGO/PMS system. N was homogeneously inserted into the reduced graphene oxide (rGO) matrix of Co@rGO, inducing a significant increase in the degradation efficiency without affecting the activation mechanism transformation. Additionally, S doping converted Co3O4 to Co4S3 in Co@rGO and transformed the cooperative oxidation pathway into a single non-radical pathway with stronger intensity, which led to a higher stability against environmental interferences. Notably, based on density functional theory (DFT) calculations, we demonstrated that Co4S3 had a higher energy barrier for PMS adsorption and cleavage than Co3O4, and therefore, the radical pathway was not easily stimulated by Co4S3. Overall, this study not only illustrated the improvement due to the heteroatom doping of Co@rGO for TC degradation in a PMS system but also bridged the knowledge gap between the catalyst structure and degradation performance through activation mechanism transformation drawn from theoretical and experimental analyses.
研究领域:
环境科学
·
材料科学
·
理论化学
✓ 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）