JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 3.6
Li Zhao,Shulai Lu,Ming Chen,Yuchao Wang,Lei Ning,Shicheng Zhao
The agglomeration of polybutadiene latex (PBL) is a complex process influenced by numerous factors. Up to now, the change of particle size of agglomerated PBL with time under varying conditions remains unclear, and the agglomeration kinetic model of PBL has not been proposed. In this study, the influence of the process parameters on the particle size of agglomerated PBL with time was studied, including the amount of agglomerating agent, temperature, stirring rate, and solid content of PBL. According to the particle size evolution of agglomerated PBL, the agglomeration process of PBL is divided into two stages, including the dispersion of the agglomerating agent and its adsorption and coalescence with PBL (stage I), followed by the shrinkage of agglomerated PBL particles (stage II). It was found that the process of stage I can be accelerated significantly by increasing the amount of agglomerating agent and agglomeration temperature during PBL agglomeration, thereby reducing the total agglomeration time. The mean particle size of agglomerated PBL was also reduced when the agglomeration process reached stability. With the increase of stirring rate, the time required for agglomeration of PBL and the mean particle size of agglomerated PBL decrease. The higher the solid content of pre-agglomerate PBL, the shorter the time for PBL to complete the agglomeration, but it has no obvious effect on the mean particle size of agglomerated PBL. Based on the experimental results, on the one hand, a novel method for expressing the particle size shrinkage of agglomerated PBL was developed. This analysis was based on the change of mean particle size of agglomerated PBL with time. On the other hand, the Boltzmann equation was used to fit the agglomeration kinetics of the whole process of PBL agglomeration. The results showed that the predicted values were in good agreement with the experimental values when PBL was agglomerated under different process parameters. Knowledge obtained from this study will provide insight into the influence of process parameters on the particle size of agglomerated PBL over time, and the establishment of kinetic models can help the industrial development of PBL agglomeration technology. Graphical
研究领域:
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2022
·Vol. 23
·期 3
·1428-1438
·
IF 3.536
Li Yulong,He Liuyang,Chen Yulin,Xue Jianming,Zheng Li,Yang Shengmao,Wu Li,Chen Zhendong,Zhang Zulin,Yang Lie
Purpose Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in soils pose a severe threat to the soil ecosystem and human health. Soil aggregates play a critical role in the migration and transformation of pollutants. Materials and methods In this study, soil with different properties (Fluvisol and Planosol) spiked with PFOA/PFOS were incubated for 90 days, and then divided into five particle size fractions by wet sieving with low loss. The concentrations of PFOA and PFOS in soils and fractions were extracted using ultrasound-assisted extraction method with methanol as an extractant. The PFOA and PFOS were analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS). Results and discussion The results showed that the ability of the soil aggregates to carry PFOA and PFOS initially decreased and then increased with decreasing particle sizes. Moreover, organic matter was the main factor influencing the PFOA and PFOS distribution in the soil aggregates, whereas soil types did not affect the accumulation capacity of PFOA and PFOS on soil particles. The macroaggregates (2000–250 µm) showed the highest accumulation capacity of PFOA and PFOS, suggesting high load of PFOA and PFOS. Additionally, the microaggregates (< 15 µm) played a dominant role in the PFOA and PFOS distribution due to the high proportion of this fraction in soil samples (51.73 ~ 62.47%). Conclusions Significantly bipolar immigrations of PFOA and PFOS into macroaggregates and microaggregates in soils were observed. This phenomenon can be explained by the fact that the particulate organic carbon (POM) can sorb the PFOA and PFOS in the macroaggregates, while the presence of SOC (highly humified) may increase the PFOA and PFOS contents in the microaggregates. Graphical Abstract
研究领域:
环境科学
·
土壤学
·
污染研究
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Xiaohong Xing,Jinbo Ouyang,Shilin Guo,Mingyang Chen,Zhi Gao,Feiqiang He,Limin Zhou,Zongbo Xie
Vanillin is a natural flavor and is widely used in the fields of medicine, food and optoelectronics. However, the stable form I of vanillin usually shows needle or fiber-like morphology during crystallization, and it has poor powder performance (flowability, bulk density, dissolution rate, etc.), which further limits its applications. In this work, to improve the powder performances of vanillin, the spherical crystals were designed and prepared via spherical agglomeration method, and the spherical particles were systematically characterized using polarized light microscopy (PLM), particle size instrumentation, powder X-ray diffraction (PXRD) and Fourier infrared transform spectroscopy (FTIR). Meanwhile, the effects of BSR (V bridging liquid :V solute ), agitation rate and surfactant on the morphology and particle size distribution of spherical particles were analyzed to determine the optimal operating conditions for the spherical crystallization of vanillin as well as its formation mechanism and to improve the powder performance of the products. In addition, the multicomponent spherical particles of vanillin-salicylic acid obtained by crystal co-agglomeration (CCA) meet the formulation requirements in terms of morphology and particle size, which also enhance the dissolution rate of vanillin.
研究领域:
化学工程
·
材料科学
·
药剂学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Yulong Li,Sufen Dong,Jianchen Qiao,Shuxuan Liang,Xiaowei Wu,Mei Wang,Huiwei Zhao,Wei Liu
Soil aggregates play an important role in the migration and transformation of heavy metals . In this paper, solution adsorption and incubation experiments were carried out to explore the effects of soil texture (sandy loam and clay loam), nanominerals (nanomontmorillonite [nMt] and nanohydroxyapatite [nHA]), and pollution levels (5, 10, and 15 mg/kg) on the surface migration and transformation of cadmium in soil aggregates with different sized particles. The aim is to clarify the dynamics of cadmium in various particle size soil aggregates of different texture soils and demonstrate the positive effect of nanominerals on the partitioning and geochemical fractions of cadmium between the aggregates. The results showed that as the particle size decreased, the ability of the soil aggregates to carry cadmium initially decreased and then increased. Organic matter was the main factor influencing the cadmium distribution among the soil aggregates, whereas soil texture had no significant effect on the adsorption capacity of Cd 2+ in the soil particles. The soil aggregates with sizes <15 μm had the highest cadmium accumulation capacity. As the cadmium concentration increased, cadmium ions were more likely to accumulate in soil aggregates with small particles (<15 μm). The application of nanominerals promoted the migration of cadmium to <15 μm particles from 2000 to 45 μm particles in sandy loam and 75-15 μm particles in clay. nHA also significantly improved the content of residual cadmium in the <15 μm portion of both soil textures. This study provides a theoretical basis for the use of nano-fixatives in environmental restoration applications.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Jiao Li,Jian Zhang,Hongyu Zhang,Xuwen Wang,Taojie Lu,Jiayan Liang,Yulin Yang,Kaifeng Lin,Debin Xia
Interface modification of aluminum particles plays a crucial part in reducing the agglomeration during the combustion of solid propellants . In this study, the aluminum (Al) particles are pretreated with gallic acid (GA) to get Al@GA with an adhesion-favorable surface, which facilitates the further coating procedure. One new fluorine-containing organic substance is prepared, namely p-HFBA. The p-HFBA further coats the Al@GA to produce Al@GA/p-HFBA. The interface between Al@GA and the coating layer p-HFBA forms Al F bonds and induces a pre-ignition reaction with an aluminum oxide shell. Hence, the agglomerate size of propellants containing Al@GA/p-HFBA significantly decreases from 176.30 μm to 84.72 μm. The agglomerates volume is reduced by approximately 97 %. Additionally, more gaseous products investigated by TG-MS provide the Al particles with greater impetus (aerodynamic forces, F ae ), enabling them to leave the burning surface and reduce the residence time. The rise in F ae and drop in adhesion force ( F ad ) effectively reduce the agglomeration intensity according to the skeleton layer model. This work proves that interface modification can effectively enhance the combustion performance of aluminized solid propellants .
研究领域:
材料科学
·
燃烧学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2024
·
IF 4.1
Ming Zhou
This work investigates the flow and agglomeration behaviors of battery grade Li 2 CO 3 powder and the influence of stearic acid surface modification. The degree of agglomeration is directly related to the uniformity of Li 2 CO 3 and its powder mixtures. According to the Chinese National Nonferrous Metal Industry Standard, battery grade Li 2 CO 3 powder has D 50 equal to 3–8 μm which belongs to a micron-sized superfine powder. Therefore, with the extension of storage time, the serious agglomeration phenomenon occurs due to the large specific surface area and rough and irregular powder particles. The Hausner ratio (HR) of the unmodified sample increases from 1.14 to 1.41, and the corresponding flowability is classified as good to poor. Instead, among samples with doping stearic acid, the optimum amount of it is 0.10 wt% which exhibits an extremely stable HR value from 1.14 to 1.16. Meanwhile, after 156 days, the repose angle (AR) obtained for samples without surface modification and using 0.10 wt% stearic acid are calculated to be 49° and 28°, respectively. Based on the values of HR and AR, the flowability of the unmodified sample is poor while the sample modified with 0.10 wt% of stearic acid still maintain excellent powder flow property. Moreover, The LiMn 2 O 4 cathode material synthesized from modified Li 2 CO 3 powder with a stearic acid content of 0.10 wt% exhibits good crystallinity and comparable electrochemical performance to that prepared by commercial Li 2 CO 3 . These results indicate that stearic acid has the potential to be an ideal modifier for battery grade Li 2 CO 3 powder that needs to be kept for a long time.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Yiquan Guo,Junying Zhang,Yongchun Zhao,Shaolong Wang,Cheng Jiang,Chuguang Zheng
Fly ash fine particles emitted from coal-fired power plants are the primary atmospheric pollutant in China. The pressure, temperature, and velocity distribution of the flow field in a chamber was simulated to evaluate chemical agglomeration. The effect on the removal efficiency of composition, concentration, pH, K + content, and zeta potential of the chemical agglomeration solutions as well as surfactant and flue gas temperature were evaluated. The results suggested that suitable solutions could significantly improve the removal efficiency of fine particles. Among these, kappa-carrageenan performed best and achieved a removal efficiency of 47.1%. Synergism was detected as two different chemical agglomeration solutions were mixed together: a mixture of kappa-carrageenan and konjac glucomannan attained a removal efficiency of 59.3%, higher than their individual values. The efficiency improved initially and then decreased as the solution K + concentration increased. Also surfactants affected agglomeration: cationic and non-ionic surfactants enlarged the removal efficiency by 9.0% and 3.7%, respectively, whereas anionic surfactants lessened average removal efficiency by 5.6%. Zeta potential influenced the removal efficiency as well: it peaked as the zeta potential was around 0 mV.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Qianjie Niu,Jiwei Jiang,Changsong Zhan,Yujie Tao,Zijun Ye,Jian Huang,Bin Dong,Zhenhui Kang
With the world's population expanding rapidly, modern agriculture is evolving at a swift pace, leading to a significant increase in food production, primarily through the use of chemical fertilizers. However, this heavy reliance on fertilizers has led to issues such as soil compaction and decrease of earthworm abundance. Herein this study reports a smart soil consisting of conventional soil and carbon dots (CDot) based smart material which is capable of automatically adjusting its porosity and soil aggregate size. Due to the responsiveness, The CDot-based smart soil can lift its height up to 150% upon humidity stimulation due to the increased porosity which is similar to the effect caused by earthworms. Based on this effect, this smart soil can increase the growth rate of maize seedlings by 40%, thus showing great potentials in agriculture.
研究领域:
农业科学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF SOIL BIOLOGY
·
2024
·
IF 3.7
Zongyang Liu,Shenghao Ai,Meihua Sheng,Jingyao Xiao,Peng Wang,Yingwei Ai,Xiaoyan Ai
Soil organic phosphorus (OP) mineralization plays a vital role in the ecological restoration of roadside slopes. However, the changes in the functional bacterial ( phoD -harboring) community involved in OP mineralization in soil aggregates during slope restoration are still unknown. In this study, a space-for-time substitution was conducted to compare the differences in the phoD -harboring bacterial community structure and assembly in soil aggregates of four particle sizes (<0.053, 0.25–2, 0.053–0.25, and >2 mm) at different slope restoration ages (7, 11, and 14 years). The results showed no significant differences in the phoD -harboring community diversity and structure among soil aggregates in the same restoration year. Community structure dissimilarity increased with restoration time. Species replacement dominated slope soils restored for 7, 11, and 14 years, accounting for 78.40 %, 79.68 %, and 68.96 % of the total β-diversity, respectively. Community assembly processes shifted from coexisting deterministic (68 %) and stochastic (32 %) processes in the 7-year restoration slope soil to dominantly deterministic (98 % and 91 %) processes in the 11- and 14-year restoration slope soils, respectively. Dominant phoD -harboring bacteria tended to shift from r-to K-strategies as slope restoration progressed, and the C:P ratio significantly correlated with both community structure and assembly. The increasing C:P ratio over restoration time stimulated phoD -harboring bacteria to secrete alkaline phosphatase to improve P availability, enhancing the complexity and stability of the network. This study elucidates the changing patterns of phoD -harboring bacteria in soil aggregates and provides a theoretical basis for the management of soil P during roadside restoration.
研究领域:
微生物学
·
土壤学
·
生态学
✓ 已验证
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 6
·1124
·
IF 4.967
Chen Shen,Shi Yan,Yapeng Ou,Qingjie Jiao
In this study, fluorinated polyurethane (FPU) was prepared from dialcohol-terminated perfluoropolyether as a soft segment; isophorone diisocyanate (IPDI) as a curing agent; 1,2,4-butanetriol (BT) as a crosslinker; and 1,4-butanediol (BDO) as a chain extender. Fourier transform infrared spectroscopy (FTIR) and1H NMR were used to characterize the structure of the FPU. The mechanical properties of the FPUs with different BDO and BT contents were also measured. The tensile strength and breaking elongation of the optimized FPU formula were 3.7 MPa and 412%, respectively. To find out the action mechanism of FPU on Al, FPU/Al was prepared by adding Al directly to FPU. The thermal decomposition of the FPU and FPU/Al was studied and compared by simultaneous differential scanning calorimetry-thermogravimetry-mass spectrometry (DSC-TG-MS). It was found that FPU can enhance the oxidation of Al by altering the oxide-shell properties. The combustion performance of the FPU propellant, compared with the corresponding hydroxyl-terminated polyether (HTPE)-based polyurethane (HPU) propellant, was recorded by a high-speed video camera. The FPU propellants were found to produce smaller agglomerates due to the generation of AlF3in the combustion process. These findings show that FPU may be a useful binder for tuning the agglomeration and reducing two-phase flow losses of aluminized propellants.
研究领域:
材料科学
·
推进剂研究
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Jiayong Ni,Jiaqi Si,Tian Lan,Weidong Sun,Guofeng Zhao,Ye Liu,Yong Lu
The fluidized-bed reactor is a preferred option for the design of an intrinsic-safety oxidative coupling of methane (OCM) process, because it permits such strongly exothermic reaction to proceed isothermally. However, the widely studied Mn-Na 2 WO 4 /SiO 2 catalyst cannot meet the requirements of the fluidized-bed reaction. Ground-breaking fluid catalyst coupling high activity/selectivity with good anti-agglomeration and high attrition resistance represents a grand challenge. Herein, we report an Mn 2 O 3 -Na 3 PO 4 /TiO 2 catalyst (280–355 μm) for the fluidized-bed OCM process, achieving 28.5% CH 4 conversion with 70.1% C 2 -C 3 selectivity at 760 °C for a feed gas of CH 4 /O 2 of 5/1 while remaining unchanged within 16 h test. This catalyst shows significant fluidization behavior under OCM reaction conditions. It is found that TiO 2 nanorods tangle up with each other to form an interpenetrating nano-structure thereby inducing strong mechanical strength and robustness with a low attrition index of only 2.8%. Moreover, high melting-point Na 3 PO 4 and use of TiO 2 support impart the catalyst to good anti-agglomeration because of eradication of formation of the sticky Na 2 Si 2 O 5 and molten Na 2 WO 4 (main cause for agglomeration) encountered in the Mn-Na 2 WO 4 /SiO 2 .
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhoufeng Jiang,Fengqi Zhao,Zhao Qin,Yi Xu,Ying Wang,Yi-Fan Jiang,Ting An,Wengang Qu,Ming Zhang,Hexin Liu,Bingbing Zhang,Lianghua Xiong
AlH3 has gained considerable attention as a fuel additive due to its ability to offer high specific impulse and superior combustion performance. However, few studies have focused on the fragmentation and agglomeration behavior of AlH3. This study investigated the effects of fragmentation of AlH3 and AlH3/PVDF particles on the thermal decomposition, ignition, agglomeration, and combustion of HTPB propellants. Thermal analysis indicated that AlH3 and AlH3/PVDF can accelerate the decomposition of ammonium perchlorate by abundant active sites for the adsorption of the decomposition intermediates. Single-particle combustion uncovered the mechanism behind the directional spray of molten Al from the AlH3 particle and the fragmentation of the AlH3/PVDF particle. The melting of porous Al induces particle shrinkage due to solid–liquid interfacial tension and the structural restoration of the oxide shell, which consequently results in the sealing of cracks in the oxide shell of AlH3. Additionally, the accumulation of internal tensile stress leads to the reopening of these cracks and the directional ejection of the molten Al. The flexible oxide shell contributes to a smaller minimum normalized diameter of the AlH3/PVDF particle, aiding in the generation of internal tensile stress, while the sublimation of AlF3 induced the fragmentation. Synchrotron-based X-ray imaging revealed the formation of aggregates promoted by molten Al, the splitting of AlH3 aggregates due to hydrogen explosion, and the enhanced fragmentation of AlH3/PVDF due to the synergistic effect of hydrogen explosion and the sublimation of AlF3. Compared to raw particles, the CCPs (condensed combustion products) of SP2 propellant display a 48% reduction in average size (D50 = 24.5 μm), whereas there is an over 89% decrease in particle size for the CCPs of SP3 propellant (D50 = 5.14 μm). This study contributes to understanding the fragmentation of AlH3 and AlH3/PVDF upon ignition and combustion, providing valuable insights for the development and optimization of propellants containing AlH3.
研究领域:
材料科学
·
燃烧学
·
推进剂工程
✓ 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）