RSC Advances
·
2016
·Vol. 6
·期 111
·110349-110355
·
IF 3.289
Bolin Liu,Yangguang You,Haifei Zhang,Hao Wu,Junsu Jin,Hongtao Liu
Zinc oxide (ZnO) nano-powders were prepared by a simple PVA-assisted freeze-drying process. Porous materials were firstly prepared by freeze-drying of polyvinyl alcohol (PVA) and zinc nitrate aqueous solutions with different mass ratios, and then calcined to produce ZnO nano-powders directly. PVA was applied as a polymeric carrier and its interaction with zinc nitrate was investigated for its effects on the morphology of the obtained ZnO nano-powders. The PVA/Zn(NO3)2 foams were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The obtained ZnO nano-powders were also characterized using various techniques and were evaluated as photocatalysts for dye degradation.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Weiqiang Hu,Xiangwei Kong,Zunfeng Du,Aslam Khan,Zongqing Ma
In order to synthesize carbide dispersion strengthened tungsten (CDS-W) with high performance, the W-(0, 0.2, 0.5, 1.0 wt%)TiC alloys were synthesized by novel freeze-drying and low temperature sintering . When adding the optimum amount of 0.5 wt%TiC, the W–TiC composite powders possess finest grain size (about 30 nm). Afterwards, a prominent balance between the high density (98.3%) and ultrafine grain (680 nm) was achieved in the sintered W-0.5 wt%TiC alloys. Furthermore, the TiC particles (<50 nm) keep their original size and are uniformly distributed within W matrix. The ultrafine size of W grain and TiC particles are mainly attributed to the uniform doping of powder precursors and their stable phase interface . As a result, the sintered W-0.5 wt%TiC alloys possess the highest hardness (625 ± 38 HV 0.2 ) among all the sintered samples. Based on above analysis, the new technology of freeze-drying can be employed to prepare W–ZrC alloys or other alloys with ultrafine grains and second phase particles.
研究领域:
材料科学
·
粉末冶金
·
纳米材料
·
金属基复合材料
·
固态加工
✓ 已验证
DOI
高影响因子
Food Science & Nutrition
·
2019
·Vol. 7
·期 5
·1677-1684
·
IF 1.747
Chengli Hou,Xuan Song,Zheng Li,Wenting Wang,Qingwu Shen,Dequan Zhang
To increase the color stability of hemoglobin (Hb) powder, the technological conditions for arginine–hemoglobin (Arg-Hb) powder preparation were optimized by response surface methodology and the influence of arginine (Arg) on the color stability of Hb powder was evaluated. Results showed that: (a) Arg-Hb powder had better colors (less MetHb% and higher a* value) than Hb powder ( p < 0.05); (b) using MetHb% as an indicator, the optimal conditions to prepare Arg stabilized Hb were Arg concentration of 10.5 mg/ml Hb extract, reaction pH of 10.75, and reaction temperature of 18°C; (c) pH and NaCl had a significant influence on the color stability of Hb ( p < 0.05). At various NaCl concentrations and pH conditions, Arg-Hb solution showed better color than Hb ( p < 0.05); (d) Arg-Hb powder had higher a* values and higher percentages of deoxyhemoglobin and oxyhemoglobin but lower MetHb% than Hb powder during storage ( p < 0.05).
研究领域:
食品科学
·
生物化学
·
制药技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2018
·
IF 1.686
Wei Wang,Jing Yang,Dapeng Hu,Yanqiu Pan,Shihao Wang,Guohua Chen
Freeze-drying of initially porous frozen material was investigated aimed at improving the process economics by reducing drying time and raising productivity. Experimental results showed that freeze-drying can be significantly enhanced by the frozen material with prebuilt porosity, and about 31% of drying time can be saved compared with the conventionally solid frozen material under the tested operating conditions. A multiphase transport model was formulated based on the local mass non-equilibrium assumption. Numerical results showed excellent agreements between measured and predicted drying curves. Analyses of saturation and temperature profiles displayed that volumetric sublimation-desorption can occur for the initially porous frozen material.
研究领域:
食品科学
·
化学工程
·
生物工程
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产品关联
DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2021
·Vol. 46
·期 6
·e13814
·
IF 2.72
Xiaoshuo Lu,Hui Hou,Donglu Fang,Qiuhui Hu,Jiluan Chen,Liyan Zhao
In this study, modified headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) were utilized to investigate the dynamic aroma changes of Lentinula edodes ( L. edodes ) at different stages of vacuum freeze drying (VFD). The extraction efficiency of volatile compounds from vacuum freeze-dried L. edodes was improved by optimizing five parameters of the HS-SPME. A total of 50 volatiles were identified in L. edodes from different VFD stages by GC-MS. Alcohols, aldehydes, and volatile sulfur-containing compounds (VSCs) were the main flavor constituents of fresh L. edodes , frozen L. edodes , and secondary dried L. edodes . Aldehydes, ketones, and VSCs were the main aroma groups in L. edodes after primary drying. There were 20 volatiles as key odorants with the odor activity values greater than 1, in which esters appeared only before secondary drying of L. edodes . These findings could contribute to a comprehensive insight into the formation mechanism of flavor in the VFD process of L. edodes . Practical applications Lentinula edodes is the second most widely cultivated edible fungus worldwide. It is considered a valuable health food not just because of its abundance of nutrients but also because of its delicious taste. This study investigated the regularity regarding the changes of volatile compounds in L. edodes during vacuum freeze drying. The results of the present study offer valuable knowledge for the formation mechanism of volatile substances in the drying process of L. edodes , which can be beneficial to promote the development and utilization of flavor substances in L. edodes .
研究领域:
食品科学
·
真菌学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 39
·22169-22176
·
IF 2.936
Shiyang Wei,Qiaoxi Yu,Zhenguo Fan,Siwei Liu,Zhenguo Chi,Xudong Chen,Yi Zhang,Jiarui Xu
The preparation of polymeric composite materials with low filler content as well as high thermal conductivity has been an important subject for the field of polymer material research. During our recent investigation on polyimide (PI), it was found that poly(amic acid) (PAA) solution (in dimethylacetamide, DMAc) could crystallize at low temperature. When adding reduced graphene oxide (rGO) as the thermal conductive fillers in the PAA solution, it was also found that the crystallization process of PAA would impel the rGO to rearrange in order and form an aligned thermal conductive network. To retain the rGO network structure, the freeze-drying technique was used to remove the solvent. Subsequently, through a thermal imidization process the final rGO/PI films containing a 3D rGO network could be obtained. The PI composite films retain good flexibility, excellent thermal stability, and exhibit excellent thermal conductivity. When the content of rGO added is 8 wt%, the thermal conductivity of the rGO/PI film can reach a high value of 2.78 W m−1 K−1, which is about 15.4 times that of neat PI and 5.5 times that of the rGO/PI composite film prepared by the conventional two-step routine with the same content of rGO.
研究领域:
材料科学
·
热传导技术
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产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Jing Zhang,Hongli Zhang,Tinghui Yan,Ye Fang,Yuzhong Huang,Jijun Tang,Mingyang He
Low shrinkage, open-cell structure, and mechanically-strong polymethylacrylimide (PMI) aerogels were synthesized using a freezing-drying process. Specifically, methacrylonitrile (MAN) and methacrylic acid (MAA) were used as the comonomers to synthesis the copolymer . PMI aerogels after heat treatment presented the lowest shrinkage of 10.5%. The fabricated aerogels exhibited a network-like structure with the minimum measured porosity of 89%. Increasing the copolymer solid contents resulted in a better compression property. The maximum stress of the PMI aerogels at 50% strain can reach 0.256 MPa. The fabricated aerogels presented low thermal conductivity and density, as low as 43 mW/mK and 0.050 g/cm 3 , respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·Vol. 108
·期 6
·e20401
·
IF 3.8
Yu Ma,Zhenting Zhu,Huangshuai Zhang,Mohamed Kallel,Zihao Yang,Juanna Ren,Salah M. El-Bahy,Zhe Chen,Zeinhom M. El-Bahy,Hang Zhang,Zhanhu Guo
Freeze-drying is a promising method for drying gels, but it is considered incapable of preparing bulk inorganic oxide aerogels. Herein, using tert-butanol/water co-solvent as the freeze-drying solvent, large-size crack-free monolithic silica aerogels with different absolute ethyl alcohol to tetraethylorthosilicate molar ratios were successfully synthesized via a vacuum freeze-drying process. Superhydrophobicity was then obtained through an efficient chemical vapor deposition hydrophobic modification process. As the molar ratio increased from 8 to 16, the density, linear shrinkage, specific surface area (SSA), and mechanical properties decreased, while the thermal conductivity decreased first and then increased. The freeze-dried silica aerogels show the lowest density of 0.078 g/cm 3 , the lowest linear shrinkage of 4.6%, the highest SSA of 962 m 2 /g, the highest Young's modulus of 904.3 kPa, and a lowest thermal conductivity of 0.026 W/(m·K). Despite the formed fine ice crystals compressing the gel skeleton to some extent in the freeze-drying process, the developed mesoporous skeleton structure is basically preserved, which ensures excellent thermal insulation and mechanical performance. This study demonstrates that high-quality monolithic inorganic oxide aerogels can be effectively prepared by the freeze-drying method, which provides them with another efficient drying method independent of supercritical fluid drying and ambient pressure drying methods.
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2026
·
IF 6.6
Siyuan Chu,Lijia Chen,Wenjie Zhang,Huaiyue Sun,Xiaoyu Du,Zhengquan Wang,Xichang Wang,Jian Zhong
Nutrients co-encapsulation is a significant research focus in functional foods. This study developed a method to co-encapsulate fish oil and curcumin (Cur) using bovine bone gelatin (BBG)-chitosan (CS) complex coacervation, followed by freeze-drying with maltodextrin (MD) as a drying aid. The results confirmed that the successful encapsulation of fish oil/Cur droplets in the powder particles. As the MD/BBG mass ratios increased (0–8), several trends were observed for the powders: the oil loading capacity decreased progressively (17.7%–2.7%), oil encapsulation yields increased and then decreased (54.1%–27.9%), oil encapsulation efficiencies exponentially increased (75.6%–92.9%), Cur loading capacities exponentially decreased (0.82%–0.24%), Cur encapsulation yields exponentially increased (63.7%–85.9%), Cur encapsulation efficiencies linearly decreased (79.8%–73.4%), and peroxide values during the oxidative stability process logistically increased (19.5–44.5 mmol/kg oil at 1 h). During simulated small intestinal digestion, an MD/BBG mass ratio of 5 resulted in the highest percentage (92.8%) among all ratios tested (0–8). These results suggested fish oil can act as an effective carrier for Cur in functional powders, and that miscible nutrients can be co-encapsulated within complex coacervates. This work provided an efficient strategy for developing raw materials with co-encapsulated nutrients for functional foods and contributed to understanding the underlying mechanism of the multi-nutrient co-encapsulation.
✓ 已验证
产品关联
DOI
高影响因子
DRYING TECHNOLOGY
·
2026
·
IF 3.2
Shuo Zhang,Qi Fan,Yanqiu Pan,Runze Lin,Wei Wang
Nanocellulose (NC) aerogels with positively and negatively charged groups were prepared for selective dyes adsorption. The 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation was employed to prepare carboxylated nanocellulose (CNC)-NC aerogels for cationic dyes adsorption. Polyethyleneimine (PEI) was physically crosslinked with CNC to prepare CNC-PEI aerogels with amino groups for anionic dyes adsorption. Directional freezing was adopted to construct mono-directional pores for intensifying mass transfer, and dielectric-aided microwave heating was used to intensify heat transfer for freeze-drying. The results showed that the proposed drying method could reduce more than 40% of drying time. The maximum adsorption capabilities of prepared aerogels were 778.70 mg⋅g−1 for Crystal violet (CV) and 543.81 mg⋅g−1 for Methyl orange (MO). Adsorption kinetics and isotherm experiments were conducted to analyze adsorption mechanism. The aerogels showed excellent adsorption selectivity in hybrid dyes solution and satisfactory reusability in 10-cycle operations, possessing an outstanding promise for dyeing wastewater treatment.
✓ 已验证
DOI
高影响因子
AAPS PHARMSCITECH
·
2017
·Vol. 19
·期 2
·541-550
·
IF 2.451
Liu Daichun,Galvanin Federico,Yu Ying
The purpose of this study was to prepare ginkgolide B (GB) lyophilized powder for injection with excellent appearance and stable quality through a formulation screening and by optimizing the freeze-drying process. Cremophor EL as a solubilizer, PEG 400 as a latent solvent, and mannitol as an excipient were mixed to increase the solubility of GB in water to more than 18 times (about from 2.5 × 10 −4 mol/L (0.106 mg/mL) to 1.914 mg/mL). Formulation screening was conducted by orthogonal design where the content of GB in the solution before lyophilization (using external standard method of HPLC) and reconstitution time after lyophilization were the two evaluation indexes. The optimized formulations were GB in an amount of 2 mg/mL, Cremophor EL in an amount of 16% ( v / v ), PEG 400 in an amount of 9% ( v / v ), mannitol in an amount of 8% ( w / v ), and the solution pH of 6.5. Through four single-factor experiments (GB adding order, preparation temperature of GB solution, adding amount, and adsorption time of activated carbon), the preparation process of GB solution was confirmed. The glass transition temperature of maximally GB freeze-concentrated solution was − 17.6°C through the electric resistance method. GB lyophilized powder began to collapse at − 14.0°C, and the fully collapsed temperature was − 13.0°C, which were determined by freeze-drying microscope. When the collapse temperature was determined, the primary drying temperature was obtained. Thereby, the freeze-drying curve of GB lyophilized powder was initially identified. The freeze-drying process was optimized by orthogonal design, the qualified product appearance and residual moisture content were the two evaluation indexes. The optimized process parameters and process were (1) shelf temperature, decreased from room temperature to − 45.0°C, at 0.5°C/min in 2 h; (2) shelf temperature increased from − 45.0 to − 25.0°C, at 0.1°C/min, maintained for 3 h, and the chamber pressure was held at 10 Pa; (3) shelf temperature was increased from − 25.0 to − 15.0°C at 0.1 °C/min, maintained for 4 h, and the chamber pressure was held at 10 Pa; and (4) shelf temperature was increased from − 15.0 to 20.0°C at 1.0 °C/min, maintained for 4 h, and the chamber pressure was raised up to 80 Pa. In these lyophilization process conditions, the products complied with relevant provisions of the lyophilized powders for injection. Meanwhile, the reproducibility was satisfactory. Post-freezing annealing had no significantly beneficial effects on shortening the freeze-drying cycle and improving the quality of GB lyophilized powder.
研究领域:
药学
·
药剂学
·
药物传递系统
·
制药技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food and Bioprocess Technology
·
2023
·
IF 5.6
Li Jiangfei,Zhou Yajun,Lu Weihong
Vacuum freeze drying (VFD) has been widely used for drying berries, by combining with pretreatment technology, energy consumption and cost can be effectively reduced as well as product quality improved. However, the effect of cold plasma pretreatment (CPP) on the drying efficiency and quality characteristics of VFD haskap has not been investigated. In this study, an innovative drying technology, cold plasma pretreatment–assisted vacuum freeze drying, was applied to process haskap. The purpose of the present study was to explore the effect of different times of CPP (0–75 s) on VFD haskap performance. The results indicated that the application of CPP enhanced the effective diffusion rate and drying rate (27.68%) owing to pretreatment etching larger and more cracks in the microstructure, increasing cell membrane permeability (15.59%), and altering cell wall pectin composition. Midilli is the most recommended model for drying kinetics. CPP contributed to increased hydrophilicity (25.33%) and degraded enzymatic activity, thereby prompting the enhancement of polyphenols, anthocyanins, flavonoids, and antioxidant capacity. Besides, the physico-chemical properties were ameliorated, the possible mechanism for the enhanced drying rate and quality properties of VFD haskap by CPP was explained by chemometrics. Overall, CPP is a promising pretreatment technology for haskap VFD.
研究领域:
食品科学
·
农产品加工
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）