APPLIED SPECTROSCOPY
·
2023
·
IF 3.5
Xinyuan Chen,Xiuzhi Chen,Hongyan Sun,Xiumin Li,Shizhao Ren,Can Jin,Hongjun Jin,Fenghua Chen,Rongrong Xue
Amorphous simvastatin (amorphous SIM) and Form I of SIM were prepared separately from SIM acetone (AC)/ethyl acetate (ETAC)/ethanol (ET) solutions by simply controlling the solvent evaporation rate, and the kinetic formation of amorphous SIM from SIM AC/ETAC/ET solutions was explained using mid-frequency Raman difference spectra analysis. The mid-frequency Raman difference spectra analysis results indicate that the amorphous phase has close connections with solutions and might be the bridge, playing an important role in the intermediate phase, between solutions and their outcome polymorphs.
研究领域:
药学
·
材料科学
·
光谱学
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2023
·
IF 3.8
Xiaolin Pan,Mengyuan Gao,Yun Wang,Yanping He,Tian Si,Yanlin Sun
Drug-loaded microspheres are significant for the development of modern pharmaceutical products. It is well known that the taken of aspirin for long-term increases the risk of serious gastrointestinal complications, therefore a controllable delivery of aspirin is of importance to lighten those side effects. In this work, poly(lactic acid) (PLA) was chosen as the carrier to prepare PLA-aspirin microspheres by using the traditional and the improved solvent evaporation methods. It was found that no matter which experimental condition was, the encapsulation efficiency of aspirin was higher by using the improved method than that of the traditional method. Specifically, when the concentration of polyvinyl alcohol = 1% (mass), the polymer concentration = 1:20, the oil/water rate = 1:2.5, PLA-aspirin microspheres were obtained via the improved method with a high yield of 82.83% (mass) and an encapsulation efficiency of 44.09%. PLA-aspirin microspheres were then prepared continuously using the improved method, which further enhanced the encapsulation efficiency to 54.56%. Approximate 85% aspirin released from microspheres within 7 days. Obvious degradation which was represented by reduction on hardness was observed by soaking microspheres in PBS for 60 days. This work is of interest because it provides a continuous route to prepare PLA-aspirin microspheres continuously with a high drug encapsulation efficiency.
研究领域:
药剂学
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生物医学工程
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产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Tiantian Song,Weichao Shi
Solvent evaporation is a dynamic process associated with mass transfer, heat exchange and complex internal flow . Their complicated effects on crystallization remain unclear in evaporating sessile droplets. Here, we study crystallization in evaporating poly(ethylene oxide) (PEO) sessile droplets and obtain three kinds of spherulites with monochromatic, anisotropic or negative birefringence . Monochromatic spherulites are generated at very slow solvent evaporation and low molecular weight , while high anisotropic spherulites are created under flow field at rapid solvent evaporation and large molecular weight . Ordinary negative spherulites appear at intermediate conditions. The temperature variation is verified during solvent evaporation, but plays an insignificant thermodynamic effect on crystallization. The experimental findings are further validated in different solvents and polymer systems . This work establishes the relationship between solvent evaporation and polymer crystallization in sessile droplets and also provides a guideline for modulating optical properties of deposited films using droplet processing techniques.
研究领域:
材料科学
·
物理化学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Junyan Fu,Chang Chen,Richard Lee Smith Jr.,Xinhua Qi
Humins, which are intractable carbon byproducts formed during thermochemical conversion of carbohydrates, are considered to be undesirable because of their adverse effects on product yields, catalyst activity, stability, and recycling. Herein, we show that the alcohol-soluble fraction of humins can be used to directly synthesize ordered mesoporous carbons (OMCs) by the classical solvent evaporation-induced self-assembly (EISA) method without the use of aldehydes or metal ion cross-linkers. The key mechanistic feature of the self-assembly of alcohol (ethanol)-soluble humins is that ulmic acid-containing humins act to cross-link micelles according to condensation reactions occurring in humins formation. The prepared OMCs show well-defined two-dimensional (2D) hexagonal mesoporous structures having uniform pore sizes (3.5 to 4.8 nm), high surface areas (∼600 m2 g–1), and pore volumes (∼0.4 cm3 g–1). Using dyes as model pollutants, selective adsorption of OMCs for macromolecular organic pollutants was confirmed, thus the resulting OMC materials appear to have many technological applications. The method proposed for humins conversion to ordered materials may serve as a simple and green way to utilize undesirable and commonly generated humins in carbohydrate conversions, which should improve the sustainability of carbohydrate transformation schemes and broaden the scope of biomass-based or natural humic acid precursors.
研究领域:
材料科学
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化学工程
·
环境科学
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DOI
高影响因子
CHEMISTRY LETTERS
·
2011
·Vol. 40
·期 5
·544-545
·
IF 1.401
Xiao Yan,Li Yan,Zhang Meng,Wang Feng-Xia,Pan Ge-Bo
Copper–phthalocyanine (CuPc) nanorods were prepared on a Si substrate by a solvent evaporation method. The results of XRD indicate that the CuPc nanorods were β-phase single crystals and grown along the [010] direction. The diameters of CuPc nanorods depend on the solution concentration, and the formation of CuPc nanorods is insensitive to the solvents and substrates. This implies that the growth of CuPc nanorods is dominated by the intrinsic π–π stacking between Pc rings. In addition, a p–n junction was formed between CuPc nanorod and Si substrate.
研究领域:
材料科学
·
纳米技术
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DOI
高影响因子
CRYSTENGCOMM
·
2025
·Vol. 27
·期 18
·2920-2930
·
IF 2.6
Haoxin Hu,Shizhao Ren,Feiting Gan,Rongrong Xue,Fenghua Chen
Hypoxanthine is an important component in guanine biominerals, and its polymorphs and morphology controls are rarely reported. In this work, three polymorphs of hypoxanthine were obtained by a solvent evaporation method: form I (triclinic) from an aqueous solution, form II (monoclinic) from an ethanol solution, and form III (a newly proposed polymorph but not observed first) from an ammonia solution. Solubility measurements in water and ethanol indicated that the stability order of the three polymorphs of hypoxanthine was form I > form III > form II. The Raman, IR and 13C ss-NMR spectra indicated that the crystal structures of forms I and III were similar but different from that of form II. The formation of form II was related to the hypoxanthine assemblies in ethanol, as demonstrated by UV spectroscopy. The PXRD patterns and SEM images showed that the three polymorphs had different growth behaviors, as revealed by comparing the hydrogen-bonding planes and π–π stacking modes. Form I had a flat hydrogen-bonding plane with non-vertical π–π stacking, benefitting v∥hydrogen-bonding, while form II had a wavy hydrogen-bonding plane with vertical π–π stacking, benefitting from v∥π–π stacking. The polymorph and morphology controls of hypoxanthine can extend the understanding of the principles of organic biomineralization based on guanine biominerals.
研究领域:
化学
·
生物矿化
·
材料科学
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2012
·Vol. 14
·期 6
·1933-1935
·
IF 3.842
Yan Xiao,Meng Zhang,Feng-Xia Wang,Ge-Bo Pan
Hierarchical flower-shaped NPB architectures are prepared via a facile solvent evaporation method and investigated by means of SEM, TEM, FT-IR, and XRD. The results indicate that each NPB flower is composed of a number of randomly oriented nanoflakes, which are single crystals and connect with each other. Furthermore, time-dependent experiments reveal that the NPB flowers are formed via a heterogeneous nucleation, coupled with “Ostwald ripening”. The densely packed films of NPB flowers, which can withstand extreme conditions, e.g., high temperature, strong acid, and strong alkali possess a durable water-repellent property.
研究领域:
材料科学
·
表面化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yingjie Zhang,Li Kang,Huajun Huang,Jianping Deng
Polymer Janus particles (PJPs) have been extensively investigated due to their intriguing features which cannot be achieved in traditional counterparts. Chiral polymer particles also have constituted a unique research area in polymer science. However, how to construct PJPs derived from chiral polymers, especially chiral helical polymers, still remains a significant academic challenge. This contribution reports the first success in preparing optically active PJPs constructed by chiral helical substituted polyacetylene via emulsion polymerization combined with solvent evaporation to induce phase separation. In emulsion polymerization systems, polymethyl methacrylate worked as a template and separated from polyacetylene domains in the course of acetylenic monomers’ polymerization and evaporation of the solvent, by which optically active PJPs were formed. The major influencing factors were explored to elucidate their effects on the formation and morphology of PJPs. Mushroom- and bowl-like PJPs were obtained. Scanning electron microscopy (SEM) images ascertain nonspherical morphologies of the obtained PJPs. Circular dichroism and UV–vis absorption spectra demonstrate their optical activity, which originated in the predominantly one-handed helical polyacetylene chains constructing the PJPs. A formation mechanism was then proposed for understanding this unprecedented type of PJPs.
研究领域:
高分子科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Nutrition
·
2022
·
IF 6.59
Li Ao,Zhu Aixia,Kong Di,Wang Chunwei,Liu Shiping,Zhou Lan,Cheng Ming
For improving solubility and bioaccessibility of phytosterols (PS), phytosterol nanoparticles (PNPs) were prepared by emulsification–evaporation combined high-pressure homogenization method. The organic phase was formed with the dissolved PS and soybean lecithin (SL) in anhydrous ethanol, then mixed with soy protein isolate (SPI) solution, and homogenized into nanoparticles, followed by the evaporation of ethanol. The optimum fabrication conditions were determined as PS (1%, w/v): SL of 1:4, SPI content of 0.75% (w/v), and ethanol volume of 16 ml. PNPs were characterized to have average particle size 93.35 nm, polydispersity index (PDI) 0.179, zeta potential −29.3 mV, and encapsulation efficiency (EE) 97.3%. The impact of temperature, pH, and ionic strength on the stability of fabricated PNPs was determined. After 3-h in vitro digestion, the bioaccessibility of PS in nanoparticles reached 70.8%, significantly higher than the 18.2% of raw PS. Upon freeze-drying, the particle size of PNPs increased to 199.1 nm, resulting in a bimodal distribution. The solubility of PS in water could reach up to 2.122 mg/ml, ~155 times higher than that of raw PS. Therefore, this study contributes to the development of functional PS-food ingredients.
研究领域:
食品科学
·
纳米技术
·
生物学
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产品关联
DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Zhenhui Liu,Rongjie Yang,Fei Xiao
Because of the existence of an oxide layer on the surface of micron aluminum (μAl) powder, it is difficult to ignite. In order to improve μAl ignition, Al particles were coated with bismuth citrate (Bi(cit)) by a solvent evaporation method. The morphology of Al-Bi(cit) was observed by scanning electron microscope (SEM) showed that Bi(cit) was evenly distributed on the surface of Al particles. The ignition temperature was reduced and ignition delay time at different temperatures of the Al-Bi(cit) were tested in a transparent tube furnace. With the increase of Bi(cit) content, the ignition temperature and ignition delay time shortened, and the combustion flame captured by the high-speed camera was more bright. The test results showed that Al-20 wt% Bi(cit) has a low ignition temperature of 479 °C, and the ignition delay time at 450 °C is only 7 s. The thermal behavior of Al-Bi(cit) was studied by thermogravimetric analysis (TG-DSC). Combined with the characterization results of the products at different heating temperatures, the combustion mechanism was proposed and proved.
研究领域:
材料科学
·
燃烧化学
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产品关联
DOI
高影响因子
LANGMUIR
·
2011
·
IF 4.269
Tao Zhao,Dong Qiu
A facile method of preparing highly folded cross-linked polymeric microparticles has been developed via one-pot suspension polymerization under high-speed homogenization. The wrinkles result from the evaporation of solvent in the cross-linked microparticles. The effects of microparticle cross-linking density and solvent on the polymer have been studied in detail. It was found that a medium cross-linking density (DVB/St = 0.5 by weight) is optimal for producing the most folded surface and the higher the solvent content, the deeper the surface wrinkles. This method is very simple and in principle can be applied to produce wrinkled microparticles with other chemical compositions.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Small
·
2025
·
IF 12.1
Shanqiu Liu,Zhenxiang Shen,Jingguo Li,Zhiyong Sun,Wei Cui,Yizhen Li,Qiuyue Liu,Enze Yu,Yi Shen,Qing Liu,Taotao Ge,Qiu Meng,Ping Li,Jie Yu,Qiang Lin
Covalently crosslinked polymers, renowned for their stability and superior performance, play a pivotal role in materials science and technology. Yet, conventional crosslinking, reliant on external agents and energy-intensive processes, prompts a growing demand for sustainable and energy-efficient alternatives. Here, it is demonstrated that irreversible covalent crosslinking can be achieved simply through ambient solvent evaporation in a molecularly engineered polydimethylsiloxane system functionalized with dithiolane moieties. This process, validated using reduced density gradient analysis, forms a robust, irreversible covalent polymer network (CTP), fundamentally distinct from conventional dynamic disulfide-based reversible crosslinking systems or physically bonded polymers typically formed via solvent evaporation. The resultant CTP demonstrates strong adhesion to various substrates, as analyzed quantitatively through Density Functional Theory simulations. Furthermore, the CTP displays excellent waterproofing, high optical transparency, and notable resistance to extreme temperatures and highly corrosive solvents. The superior performance of CTP derives from its robust covalent network, enriched with disulfide and peptide bonds and liquid-like PDMS segments. Moreover, the CTP's preparation is straightforward, sustainable, and cost-effective. These advancements position CTP as a promising development in adhesive technology, suitable for a wide range of applications requiring mechanical robustness, chemothermal resilience, and optical clarity, particularly in scenarios sensitive to thermal or radiation exposure.
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
危险品化学品经营许可证（带存储）