JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 11
·50040
·
IF 2.52
Shupeng Zhang,Lei Zhang,Xiaodong Yang,Wendong Hua,Junyun Qiu,Mingqian Zhang,Bo Zhang,Tianrui Ren
Coalescence and flocculation are two challenges for the stability and efficacy of pesticide suspension concentrate (SC) during the production and storage. To improve the stability of 25% pymetrozine SC, three comb-like poly(styrene-co-acrylic acid-co-polyethylene glycol methyl ether maleate) (SA-M) with different length side chains were synthesized by free radical polymerization and characterized by Fourier transform infrared spectroscopy and H-nuclear magnetic resonance. Surface-active parameters, including critical aggregation concentration (critical micelle concentration), saturation surface excess concentration ( Γ max ), minimum area per molecule ( A min ), and standard Gibbs free energy values were obtained from surface tension measurement. It shows that the surface-active property of SA-M decreased with the side chain length. Besides, 25% pymetrozine SC prepared using SA-M as dispersant had low zeta potential and low viscosity but high dispersibility and thermal storage stability. It is speculated that the formation of hydrogen bonds between nonionic branches and pymetrozine molecule at the expense of interruption of intermolecular hydrogen bonding between pymetrozine and water molecule, plays a key role in the stability mechanism.
研究领域:
农药科学
·
高分子化学
·
表面化学
✓ 已验证
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Tengfei Chen,Zhongcong Zhao,Yanrong Ge,Wenan Sun,Zhihao Chen,Xiaoliang Cheng,Xiaorui Liu,Huaqiang Shi
In the continuous liquid distribution process, the emulsion drag-reducing agent has poor viscosity-increasing ability and a low solid content, resulting in a high concentration and high cost. To solve this problem, a nanosuspension agent with a “shelf structure,” a dispersion accelerator, and a density regulator were used as auxiliary agents to realize the stable suspension of a polymer dry powder in an oil phase. The results show that the molecular weight of the synthesized polymer powder could reach nearly 28 million when the mass ratio of acrylamide (AM) to acrylic acid (AA) was 80:20 and a chain extender was added. The synthesized polymer powder was dissolved in tap water and 2% brine separately, and the viscosity of the solutions was measured. The dissolution rate of up to 90% was reached at 30 °C, and the viscosity was 33 and 23 mPa s in tap water and in 2% brine, respectively. A stable suspension can be obtained without obvious stratification in one week and with good dispersion after 6 months by using the following composition: 37% oil phase + 1% nanosuspension agent + 10% dispersion accelerator + 50% polymer dry powder + 2% density regulator. The drag-reduction performance is good, remaining close to 73% with increasing time. The viscosity of the suspension solution is 21 mPa s in 50% standard brine, and the salt resistance is good. The rate at which the suspension fracturing fluid damages the formation is 7.56%, and the reservoir damage is unsubstantial. Its performance in field applications illustrated that its sand-carrying capacity, referring to the capacity of the fracturing fluid to carry proppants into the fracture and place them in a predetermined position, reaches 10%. The results show that the fracturing fluid can be used as a pre-fluid to break the formation, form fractures, and expand fracture networks under low-viscosity conditions and can be used as a sand-carrying fluid to carry proppants into the formation under high-viscosity conditions. Additionally, the fracturing fluid can directly realize the fast conversion between high and low viscosities and allow for multiple uses of one agent.
研究领域:
化学工程
·
石油工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Shupeng Zhang,Jian Wang,Xiaodong Yang,Bo Zhang,Tianrui Ren
Rheological measurement can provide not only the shear-induced but also strain-induced microstructural changes, as well as transient network formation and subsequent recovery with time. It has been explored as a useful tool for probing the interparticle interactions which govern the physical stability of concentrated suspension. However, its application in pesticide formulation is rarely investigated. Herein, the rheological properties of 25% mancozeb suspension concentrate stabilized with nonionic surfactants dodecanol ethoxylates (C 12 E n , n = 3, 7, 9, 15, 20) were studied. The steady-state shear measurement showed that all the 25% mancozeb suspension concentrate displayed shear-thinning flow. The experimental flow behavior followed prediction of Herschel–Bulkley model with the correlation coefficients greater than 0.99. Oscillatory shear measurements showed the viscoelastic response of 25% mancozeb suspension concentrate transformed from solid-like to gel-like viscoelasticity with the addition of C 12 E n . As the EO chain length of C 12 E n increased, the apparent viscosity and elastic modulus decreased initially, followed by an increase behavior. The thixotropic response of mancozeb formulations was evaluated by applying a three-step test. It turned out that the addition of C 12 E n changed the mancozeb suspension concentrate from normal viscoelastic fluid to inelastic thixotropic material, and the recovery of viscosity gradually decreased as the EO chain length increased. Besides, the influence of C 12 E n on suspension rate and particle size of 25% mancozeb suspension concentrate was investigated. The results showed that C 12 E 9 performed best in improving the physical stability of the formulations before and after thermal storage. From SEM imagines of mancozeb particles, it was found that the aggregation was inhibited by C 12 E 9 , which was also responsible for the best dispersibility, minimum apparent viscosity and elastic modulus of 25% mancozeb suspension concentrate with the addition of C 12 E 9 .
研究领域:
农药科学
·
化学工程
·
应用化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Yuxin Qiao,Yixuan Wang,Ninghui Song,Li Cao,Yu He,Wenzhu Wu,Hong Yang
Microencapsulated suspensions (MEs) are widely used in agriculture for their enhanced pesticide efficacy and minimal environmental impact. However, their release mechanisms and associated risks remain insufficiently explored. This study investigated the release, environmental fate, and risks of pyraclostrobin MEs using HPLC-Q-TOF-HRMS and UPLC-QqQ-MS/MS. Field experiments showed only 3.6% of pyraclostrobin was in free state in water, with most encapsulated in microcapsules that settled in sediment. Seventeen transformation products were identified, primarily accumulating in sediment. Predictions of persistence (P), bioaccumulation (B), mobility (M), and toxicity (T) revealed eight highly mobile and four highly toxic metabolites. Metabolites m/z 281 and m/z 339 showed significant chronic toxicity to daphnia, surpassing pyraclostrobin toxicity. Risk quotient analysis indicated that m/z 358 and m/z 611 posed a moderate risk to daphnia and mysid. The study highlights the importance of evaluating MEs, focusing on their release mechanisms and ecological risks to ensure safe pesticide use.
研究领域:
环境科学
·
农药化学
·
生态毒理学
·
污染物行为
·
水环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Shupeng Zhang,Xiaodong Yang,Zhenbei Tu,Wendong Hua,Penghui He,Haihui Li,Bo Zhang,Tianrui Ren
Polymeric surfactant has explored as an efficient dispersant for improving the physical stability of pesticide suspension concentrate. However, the influence of the hydrophilic monomer on the surface-active property of polymeric surfactant and its application performance in pesticide formulation is rare investigated. Herein, three kinds of random polymers were designed and synthesized via polymerization reaction of styrene (St), methacrylic acid (MAA) with 2-hydroxyethyl acrylate (HEA), 2-hydroxypropyl acrylate (HPA) and vinyl sulfonate sodium (VS), respectively. A series of surface-active parameters, including critical aggregation concentration (CMC), saturation surface excess concentration (Γ max ), minimum area per molecule (A min ) and standard Gibbs free energy ΔG m 0 values were obtained from surface tension measurement. The results showed that CMC increased and ΔG m 0 decreased with the increase of the hydrophilicity of the third monomer. The results of foamability measurement indicated that the polymeric surfactant with VS as the third monomer had the best foam producing ability and foam stability. When HPA served as the third monomer, the surfactant had the lowest hydrophile lipophile balance (HLB) value and the O/W emulsion prepared by it had the worst stability. Besides, the influence of synthesized polymeric surfactants as dispersant on zeta potential , viscosity and suspension rate of 430 g/L tebuconazole suspension concentrate were investigated. The results showed that poly(styrene-co-methacrylic acid-co-2-hydroxypropyl acrylate) performed best in improving the physical stability of the formulations. From SEM imagines of tebuconazole particle, it was found the increase of particle size in tebuconazole suspension concentrate were caused by aggregation or Ostwald ripening after thermal storage.
研究领域:
化学工程
·
材料科学
·
农药科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Qianqian Tang,Yu Sun,Lintong Du,Mingsong Zhou,Dongjie Yang
Polyether amine-bridged sulfonated alkali lignin (PSAL) with different sulfonic group contents and molecular weights was firstly synthesized and characterized. Then, 10 wt% of chlorantraniliprole Nano-suspension concentrate (SC) was prepared by the water-based grinding method, and the optimum grinding parameters were explored and obtained. Based on this optimum grinding formula, chlorantraniliprole Nano-SC was prepared and three optimum dispersants were finally obtained as follows: the compounds of polycarboxylate D-2 separately with P 1 SAL 0.68 , P 1 SAL 0.84 and TERSPERSE 2500 at the mass ratio of 1:1. All Nano-SC prepared by these three dispersants had a D 90 particle size below 200 nm, suspension percentage above 99%, water separation proportion below 1%, excellent thermal storage stability, and also better wettability on banana leaf surface. Additionally, adding glycerin could effectively inhibit the agglomeration and austenogenization of pesticide nanoparticles , and thus improve the stability of Nano-SC. Finally, the farmland experiments indicated chlorantraniliprole Nano-SC prepared in this work had a significantly improved pesticide effect on first-instar rice leaf rollers than traditional micron-sized SC. This work provided a new dispersant with excellent performance for chlorantraniliprole Nano-SC as well as broadened the high value-added utilization of industrial lignin into pesticide Nano-SC field, which had great economic and environmental benefits.
研究领域:
农业科学
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Hongjun Chen,Xiu Liu,Hongkun Wang,Siyu Wu,Jingbo Li,Chenzhong Jin,Hanhong Xu
In this study, Pretilachlor polyurea microencapsulate suspension (PMS) with effective controlled release function was carefully prepared. Under the optimal conditions, wall material PM-200 dosage 4%, emulsifier T-60 dosage 4% with S-20 as solvent, the prepared PMS was demonstrated to have encapsulation efficiency approaching to 95.27 ± 0.57 % and high suspension rates of 97.33 ± 0.49 %. Afterwards, PMS was proved to possess average release rate reached to 85.56 %, 55.46 % and 15.85 % respectively in acidic, basic and natural medium. Subsequently, the herbicidal activity of PMS on barnyard grass and the growth safety of rice were evaluated. PMS showed enhanced herbicidal activity against barnyard grass and had lower toxicity to rice growth compared with technical pretilachlor at dose 270−540 g (a.i.)/hm 2 . In addition, the use safety of PMS was validated to be comparable to that of commercially available pretilachlor emulsifiable concentrate containing additive safener at dose 270−540 g (a.i.)/hm 2 . Moreover, inhibitory effect of PMS on rice growth was demonstrated to completely eliminated by cooperatively treatment with fenclorim. It was concluded that PMS had enhanced herbicidal activity and application safety, meeting the requirements of minimizing adverse effects of the herbicide on the environment, and enjoying a great application potential in agriculture.
研究领域:
农学
·
植物保护
✓ 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）