Crystals
·
2025
·Vol. 15
·期 6
·512
·
IF 2.4
Shixin Fan,Wenling Zheng,Shizhao Ren,Wangchuan Xiao,Fenghua Chen,Rongrong Xue
Amorphous solid dispersion (ASD) technology is popularly used for enhancing the solubility of poorly water-soluble drugs. Drug molecules in ASDs can be dispersed in the form of either amorphous (AASD) or molecular (MASD) forms. The boundary between AASDs and MASDs (A–M boundary) is defined as the drug concentration at which the existence of MASDs obviously influences the physicochemical properties of ASDs. In this work, fluorescence spectroscopy based on the aggregation-caused quenching (ACQ) phenomenon was used to determine the A–M boundary of curcumin (CUR) ASDs prepared via neat ball milling. The relationship between the fluorescence intensity and the loading of CUR in the sample is consistent with the Stern–Volmer equation. For the CUR ASDs with PVP, the samples with CUR loading below 10% show significantly increased fluorescence and have a higher solubility (~178 μg·mL−1), suggesting the A–M boundary is around 10%. Similar A–M boundaries around 10% were also observed for CUR ASDs with PVPVA, Soluplus, HPMC, and HPMCAS. It is of great significance to define the A–M boundary of ASDs for guiding pharmaceutical ASD formulas by balancing drug loading, stability, and solubility.
研究领域:
药剂学
·
分析化学
·
材料科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Guoqiang Luo,Ganrong Zhang,Luo Bai,Ying Zhang,Yuxin Fan,Yuzhe Han,Xiaoping Guo,Meijuan Li,Rong Tu,Qiang Shen
Tetragonal BaTiO 3 (BT) powder with appropriate size and dispersity is essential for the dielectric layers in multilayer ceramic capacitor technology. In this work, high tetragonality BT powder with controllable dispersion, and particle size was synthesized using combined dispersants and a two-step hydrothermal method . Owing to the synergistic effect of chemical bond force and electrostatic adsorption force between cetyltrimethylammonium bromide (CTAB) and polyvinyl-pyrrolidone (PVP) composite dispersants at a high temperature, the ultrafine BT powder with a high c/a of 1.0090, small size of 236 ± 15 nm and low polydispersity index of 0.336 was achieved. This idea shows great significance for the synthesis of BT powder with high tetragonal, high dispersion, and small particle sizes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
WenKai Cao,BinXiao Wei,YinChuan Pu,LiPeng Wang,SiQi Su,YongPing Bai
This article aims to propose a low-energy method for micron dispersion of entangled polymers. We chose Ethylene-Propylene-Diene Monomer (EPDM) as the entangled polymer and acrylic esters as the dispersants to prepare the organic dispersion of the entangled polymer based on the theory that in-situ polymerization of acrylic esters had the higher solubility parameter than the original monomer. The dispersion process of entangled polymer was similar to the phase inversion of emulsion due to the maximum viscosity and minimum interfacial tension at the point of dispersion. Specifically, the average diameter of the dispersed entangled polymer was 5–6 μm. The system could still maintain excellent dispersion stability without additional dispersants. Rheology characterized that the introduction of aliphatic isocyanate derivatives reacting with hydroxyl groups in the polyacrylate to form the cross-linked skeleton could enhance the stability of the system. Excitingly, this organic dispersion allowed flexible printed circuit to fold at any angle and direction when used as the coating, and the coating still maintained excellent dispersibility, flexibility, insulation, and adhesion after aging tests. This low-energy method for micron dispersion of entangled polymers could expand their applications in coatings and other fields while maintaining their own characteristics.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 17
·3502
·
IF 5
Jinglu Xu,Jihu Wang,Shaoguo Wen,Shengnan Ding,Jia Song,Sihong Jiang,Haopeng Wang
Hydrophobic fumed silica (HFS) is a commonly used rheology additive in waterborne coatings. A series of experiments were conducted on the HFS-dispersing technology in this study. The size and structure of HFS primary particles were observed via transmission electron microscopy (TEM). The measurement results of the TEM were D50= 13.6 nm and D90= 19.7 nm, respectively. The particle size and dispersion performance of HFS were tested via dynamic light scattering (DLS). Additionally, the HFS aqueous dispersion was prepared and compounded with waterborne polyacrylic latex and polyurethane resin. The elemental distribution of the coatings was characterized using energy dispersive spectroscopy (EDS). The results show that the HFS in a non-ionic polymer dispersant had the best dispersion performance. The particle size of the HFS in the aqueous dispersion is related to the dispersion conditions. Under optimized conditions, the HFS aqueous dispersion can be prepared with a particle size of D50= 27.2 nm. The HFS aqueous dispersion has stable storage stability. Even after storage for 47 d, the particle size still did not change significantly.Keywords:fumed silica;dispersant;dispersibility;particle size;waterborne resin
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
Journal of Coatings Technology and Research
·
2025
·
IF 2.8
Tang Baoling,He Ziyu
The commonly used dispersants for graphene dispersions reduce the conductivity of the composite. In this work, a dispersant with an amphiphilic structure, CA-g-PANI, has been designed and synthesized. The dispersant grafts citric acid (CA) onto polyaniline via an amide reaction, which gives CA-g-PANI the hydrophilic groups (carboxyl groups) and the benzene ring structures that can be π–π conjugated with graphene, and it can improve the dispersion properties of graphene; CA-g-PANI contains the polyaniline structure, which is electrically conductive and enhances the electrical conductivity of graphene dispersions. The molecular structure and properties of the dispersant were systematically characterized through FTIR spectra, UV absorption spectra, and other methods. The graphene-based composites were prepared by screen printing method, and the dispersibility and resistivity of CA-g-PANI were compared with gum arabic and alkali lignin (natural dispersants). Graphene concentration reached up to 30 mg/mL in the presence of CA-g-PANI at the weight ratio of 1:0.03 (CA-g-PANI: graphene). CA-g-PANI also exhibited good performance for stabilizing graphene (stable for 6 days), with an electrical conductivity of up to 917.43 S/m. In the study, it was shown that CA-g-PANI as a graphene dispersant improved the conductivity of graphene dispersions while enhancing the dispersing properties of graphene.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Shang Gao,Boyu Hu,Xin Song,Zhigang Dong,Renke Kang
Chemical mechanical polishing (CMP) offers promising pathway to smooth 4H-SiC. Dispersion stability of polishing slurry is crucial factor affecting 4H-SiC performance. Particles in polishing slurry can easily agglomerate due to poor dispersion stability, affecting surface quality of wafers. Nano-Al 2 O 3 is common particle in the slurry that directly controls mechanical removal. In this paper, the impact of different dispersants (PEG, (NaPO 3 ) 6 , and NH 4 PAA) on the dispersibility of slurry containing nano-Al 2 O 3 is studied. Results indicate that the slurry containing NH 4 PAA exhibits the greatest dispersion stability with superior 4H-SiC surface quality, with surface roughness (Sa) reaching 1.054 nm. The slurry containing PEG shows poor dispersion, leading to poor SiC surface quality, and the Sa reached 5.314 nm. The dispersion mechanism of different dispersants is also discussed.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 32
·期 3
·1126-1134
·
IF 2.578
Xiangyun Mi,Xiuzhi Zhang,Mei Ding,Ming Zhang,Meishan Pei
Polycarboxylic acid dispersants (PCs) with comb-like molecular structure have become the focus of dispersants. However, there are many contradictions in the study of molecular structure of polycarboxylic acids. In this article, a series of PCs with different molecular structures were prepared from acrylic acid (AA) and methyl allyl alcohol polyoxyethylene ether (TPEG) by reversible addition fragmentation chain transfer (RAFT) polymerization. The structural characteristics of PCs were characterized by flourier transform infrared spectrometer (FT-IR), 1 H nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The dispersion performance of PCs to cement was measured by the fluidity and adsorbing capacity. The results show that the dispersion performance and adsorbing capacity of PCs are significantly related to its structure. The adsorption and dispersion properties increase with the increase of carboxyl content and molecular weight. However, this phenomenon is limited to a certain range that the acid ether ratio in this range is no greater than 5:1, and the molecular weight is no greater than PC-4 ( Mw = 82 125, Mn = 63 889).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2017
·
IF 3.151
Huifang Shen,Xiaolin Du,Xiaolin Ren,Yuhui Xie,Xinxin Sheng,Xinya Zhang
A feasible and versatile route for a large-scale synthesis of monodisperse nonspherical functional polymer particles by one-pot dispersion polymerization was demonstrated. The particle morphology could be precisely tuned by varying the divinylbenzene (DVB) concentration, the start feeding time of DVB, the total feeding time of DVB, the styrene (St) mass ratio of stage I/stage II, and the solvent polarity. Sphere-like, polyhedron-like, and red blood cells (RBC)-like particles with dimples or smooth surface were obtained. In addition, the formation mechanism of these nonspherical particles was ascribed to the phase separation induced by the uneven distribution of cross-linked network. Because of the incompatibility between St homopolymer chain and cross-linked network, St homopolymer chain was forced to move to those zones where the blend was allowed. The particle surface was forced to distort, leading to the formation of particles with various morphologies.
研究领域:
材料科学
·
化学工程
·
高分子化学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xuejun Ruan,Xin Ren,Wenting Zhou,Qi Cheng,Zheng Yao,Wenqi Yu,Lujiang Jin,Liyi Shi
This article systematically studies the relationship between the dispersity of the mixed suspension, the microstructures and the electrical properties of the ZnO varistors by adjusting the dispersant content and the pH value. The suspension dispersity was measured by viscosity, zeta potential , particle size distribution and TEM observation. The structure of the as-prepared ZnO varistors was characterized by XRD and SEM. The electrical properties were investigated by testing E-J characteristics, breakdown voltage, leakage current, nonlinear coefficient, 8/20 μs waveform current impulse and accelerated aging performance. When the suspension reached the best dispersion condition of 0.3 wt% dispersant and the original pH value, the ZnO varistors had optimum electrical properties: breakdown voltage gradient of 299.95 V mm −1 , leakage current I L of 0.33 μA, voltage ratio U 5kA /U 1mA of 1.686, nonlinear coefficient of 46.71, and a downward trend of power consumption in the accelerated aging test.
研究领域:
材料科学
·
电气工程
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产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2023
·
IF 2.2
Qin Yin,Xuefen Wu,Xiaomei Wang
In this article, we synthesized a series of poly butyl acrylate-co-methacrylic acid-2-acrylamido-2-methyl propanesulfonic acid (PBAS) with different molecular weight and monomer molar ratios by 1,1-diphenylethene (DPE) method on industrial scale. The PBAS was applied as a dispersant for waterborne TiO2 paste to prepare waterborne inkjet ink. The successful synthesis of PBAS was confirmed by FTIR and 1H-NMR. To evaluate the printability and storage properties of pastes and inks, we characterized the particles, particle distribution, the storage modulus, viscosity, precipitation coefficient, and delamination height. The method creatively used in our study to characterize the printing smoothness of the ink in the industrial practical application was the filter rate of ink. We also proposed a method of using soft and hard precipitation to characterize the precipitation situation. The results of the experiment indicated that compared with commercial dispersants, PBAS5/6 had excellent performance in printing flow and anti-settling performance. This paper demonstrates the optimum dispersibility of PBAS was obtained when the molecular weight was 8500, the acid value was 100 mg KOH/g, and the 2-acrylamido-2-methylpropanesulfonic acid (AMPS) content was 20%. This fruitful work pointed out the great prospects of industrial synthetic water-based dispersants.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2015
·Vol. 33
·期 1
·312-318
·
IF 1.166
Wang Ye,Li Guobing,Chen Song,Si Rongshuang,Fan Jiangyang
Monodisperse micron-size poly(styrene-co-divinylbenzene) (PST-DVB) microspheres were successfully prepared by vibration dispersion. A vibrator was used to generate a controlled vibration to jet from a single nozzle of 200 µm to produce uniform droplets. The effects of variations in selected process parameters upon the droplets formation and the diameter of the microspheres were investigated. It was demonstrated that changes in the velocity of oil phase, drive frequency and destabilization amplitude have significant effects on the formation of uniform droplets and the average diameter of the microspheres. Rational polynomial regression equations of the above parameters were established. Based on these equations, we could calculate the operation conditions to produce uniform droplets with the desirable diameter.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Zhao-Rong Li,Rui-Bo Jia,Xueyuan Cai,Donghui Luo,Chong Chen,Mouming Zhao
The current study was aimed to enhance the solubility, dispersibility and biotransformation efficacy of ellagic acid (EA) by preparing food-derived ellagic acid- Undaria pinnatifida polysaccharides solid dispersion (EA/UPP SD). The results demonstrated that the solubility of EA/UPP SD was improved from 0.014 mg/mL to 0.383 mg/mL, and the enhancement was related to converting to a more amorphous state and restraining its self-aggregation during the mechanochemical process. The structure of EA/UPP SDs was mostly maintained by hydrogen bonds and hydrophobic interactions between EA and UPP . Moreover, the result of in vitro anaerobic incubations showed the biotransformation process was improved with EA/UPP SD addition to substrate due to the advance of microbial accessibility in EA dispersion. Altogether, these results indicated that the EA/UPP SDs expanded the application of EA by increasing the solubility and dispersity, and provided a theoretical basis for bioconversion efficiency enhancement.
研究领域:
食品科学
·
药学
·
生物技术
✓ 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）