LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Mengjing Zhou,Bin Li,Aolin Wu,Zhigang Hu,Li Zhou,Hao Hu,Dandan Fu
In the preparation of bigels, wax is commonly used to create oleogels. However, oleogels made with wax typically have high melting points, which restrict their applicability and performance in practical applications. This study investigates the eutectic phase behavior of beeswax (BW) and rice bran wax (RBW) in bigels after ultrasonic treatment by varying their ratio. A bigel with a lower melting point was also prepared. The results indicated that eutectic phase behavior occurred between beeswax (BW) and rice bran wax (RBW) at a 6:4 ratio, reducing the gel's melting point to 53.4 °C. This was approximately 13.07 °C lower than that of wax mixtures with other ratios. X-ray diffraction (XRD) results showed that the β′-type crystal structure in the oleogels was often used in the food field. Fourier transform infrared spectroscopy (FTIR) analysis showed that the eutectic phase behavior enhanced the formation of intermolecular hydrogen bonds. Rheological analysis revealed that the bigel exhibited shear thinning behavior and gel network characteristics during the frequency sweep. Notably, the eutectic phase behavior significantly enhanced the gel strength and stability.
研究领域:
食品科学
·
材料科学
✓ 已验证
DOI
高影响因子
Petroleum Science
·
2023
·
IF 5.6
Bo Yao,Hao-Ran Zhu,Bao-Dong Yan,Chuan-Xian Li,Fei Yang,Guang-Yu Sun,Hong-Bo Zeng
This paper investigated the effects of pre-heating treatment temperatures ( T pre ) on the flowability and wax deposition characteristics of a typical waxy crude oil after adding wax inhibitors. It is found that there is little difference in wax precipitation exothermic characteristics of crude oils at different T pre , as well as the wax crystal solubility coefficient in the temperature range of 25–30 °C. For the undoped crude oil, the flowability after wax precipitation gets much improved and the wax deposition is alleviated as T pre increasing. At T pre = 50 °C, the viscosity and wax deposition rate of crude oil adding wax inhibitors are higher than those of the undoped crude oil. When the T pre increases to 60, 70, and 80 °C, the flowability of the doped crude oil are largely improved and the wax deposition is suppressed with the T pre increase, but the wax content of wax deposit increases gradually. It is speculated that, on the one hand, the T pre increase helps the dispersion of asphaltenes into smaller sizes, which facilitates the co-crystallization with paraffin waxes and generates more aggregated wax crystal flocs. This weakens the low-temperature gel structure and increases the solid concentration required for the crosslink to form the wax deposit. On the other hand, the decrease in viscosity increases the diffusion rate of wax molecules and accelerates the aging of wax deposits. The experimental results have important guiding significance for the pipeline transportation of doped crude oils.
研究领域:
石油工程
·
化学工程
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Yue Wang,Huijuan Mao,Yunhao Lv,Guogang Chen,Ying Jiang
The cuticular wax of Korla pear stored under different relative humidity (0 ± 1 ℃, 50–55%, 70–75% and 90–95%) was examined in terms of total wax content, chemical composition and crystal morphology. The cuticular wax was composed of alkanes, olefins, fatty acids, alcohols, aldehydes, esters and terpenoids. High humidity maintained the content of total wax, alkanes and aldehydes at sufficient levels, especially C 29 alkane and C 18 aldehyde, which could positively regulate the quality of the pear fruits. Cuticular wax contributes to the capacity of preserving water, maintaining cell wall and delaying senescence. Scanning electron microscopy showed that wax crystals appeared as numerous platelets with irregular ovate crystals, high humidity delayed the transformation of wax structure. Taken together, high humidity delayed the ripening and aging by effectively maintaining wax, which was essential for postharvest storage and provide a reference for the production of synthetic wax for Korla pear fruits.
研究领域:
植物学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 19
·6962
·
IF 3.748
Kangren Niu,Kuiyan Song
The beeswax used in Chinese traditional hot waxed wood technology has several drawbacks, such as high price, scarce resources, and poor heat resistance. To expand the application of hot waxing technology in the field of wood decoration and protection, polyethylene wax was modified by a grafted maleic anhydride-methyl methacrylate co-monomer. A type of modified polyethylene wax with low cost, high melting point, high stability, and strong polarity suitable for hot waxed wood was prepared as a replacement for beeswax. The effects of the grafting conditions on the chemical properties, thermal properties, chemical structure, and crystallization properties of modified polyethylene wax were studied and compared to those of beeswax. The results show that maleic anhydride-methyl methacrylate co-monomer grafting can effectively improve the acid value of polyethylene wax. For the ratio of two monomers of 1/1, the total amount of monomer of 8 wt%, the amount of initiator of 2 wt%, the reaction temperature of 150 °C, and the acid value of modified polyethylene wax was consistent with that of beeswax, realizing the simulation of the main chemical properties of beeswax. The thermal stability and melting temperature of the modified polyethylene wax are significantly higher than those of beeswax, its crystal structure is similar to that of beeswax, and the cyclic anhydride groups and ester groups introduced by co-monomer grafting endow it with polar groups that play an important role in the wood hot waxing process.Keywords:beeswax;polyethylene wax;grafting;maleic anhydride;methyl methacrylate;thermal and chemical properties
研究领域:
材料科学
·
木材科学与技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Xuewen Ning,Xin Song,Sheng Zhang,Yong Wang,Yujun Feng
Nanohybrid materials can significantly inhibit wax deposition and improve the fluidity of crude oil. However, the mechanisms behind wax resolving, crystal modification, and flow improving are still unclear owing to the complexity of crude oil. Here, we compared the effect of ethylene vinyl acetate (EVA) and nanohybrids composed of EVA and SiO2 nanoparticles on wax crystallization and rheological behavior of Shengli waxy oil. Differential scanning calorimetry results indicate that SiO2 nanoparticles boost the efficiency of EVA for reducing the wax appearance temperature of waxy crude oil. Thermo X-ray diffraction characterization demonstrates that EVA/SiO2 nanohybrids cut down the crystal index of waxes, with the grain size of crystal cells decreased in (006) and (200) but increased in (110) cross sections. Polarized optical microscopy imaging reveals that EVA can modify the morphology of wax crystals to suppress the formation of wax gel, and nanohybrids serve as nucleuses to adsorb asphaltenes and resins, restraining the appearance of wax crystals. The rheological test shows that nanohybrids outperform EVA in decreasing the viscosity, inflection point, and yield stress of waxy crude oil. These findings help the understanding of flow improving by nanohybrid materials and offer guidelines for designing the new generation of wax inhibitors for safe transportation and flow assurance of waxy crude oil.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Xi Zhou,Huiqin Wu,Xiaolan Huang,Fang Hang,Huitai Luo
This study established a simple and rapid method for determination of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) by dispersive liquid–liquid micro-extraction coupled with high performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF/MS) in white and red wines. Affecting variables, including extraction solvent, salt concentration, ultrasound-vortex conditions and ethanol content, were evaluated. Under optimized conditions, the limit of detection (LODs) for SCCPs and MCCPs were in the range of 0.15–3.00 ng mL −1 and 0.08–2.50 ng mL −1 , respectively. The spiked recoveries of SCCPs and MCCPs from white and red wine ranged from 63.2% to 127%. The method is precise with intra- and inter-day variations within 14.0% and 17.0%, respectively. SCCPs and MCCPs in wines from china varied widely, from
研究领域:
分析化学
·
食品安全
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2024
·
IF 6.4
Hua Huang,Xuemei He,Qingming Sun,Guoming Liu,Yayuan Tang,Jian Sun
Pitaya ( Hylocereus undatus ) fruit is susceptible to pathogens that induce fruit decay after harvest. Cuticular waxes covering the outermost plant surfaces are the first site of plant-environment interactions; however, their changes in response to fruit decay are under-researched. Herein, the surface microstructures and chemical composition of wax on pitayas, as well as their changes in response to fruit decay, were comparatively studied. The varieties ‘Baishuijing’ (BSJ) and ‘Hongshuijing’ (HSJ) were examined after harvest. The fruit appearance, morphology, and wax composition differed between cultivars. The surface of both pitaya cultivars was smooth, although traces of granules and a thicker lipid layer were observed using histochemical staining in HSJ than in BSJ, as well as a higher cuticular wax content. Fruit decay rate increased rapidly in both cultivars under room storage conditions, and greater sensitivity to pathogens was found in BSJ than HSJ. As well as the occurrence of fruit decay, the total wax coverage, very-long-chain primary alcohols, aldehydes, fatty acids, and triterpenoids decreased in BSJ, while remaining relatively stable in HSJ. Correspondingly, the relative gene expression levels of HuKCS11 (−1, 2, and 3) , HuKCS17 , and HuKCS19 (for the elongation of very-long-chain fatty acids), HuCER1 (for aldehydes or n -alkanes), HuFAR (−1 and 2) (for primary alcohols), HuBAS1 (−1, 3, and 4) (for β-amyrin), and HuLUS1 (for lupeol) were considerably modified following fruit senescence during storage. The difference in surface topography and wax accumulation between cultivars might have affected pathogen susceptibility after harvest. These results may help when choosing varieties of pitaya based on surface characteristics and cuticular chemicals. They may also help to optimize strategies for postharvest preservation and storage.
研究领域:
植物科学
·
农学
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采后生理学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2019
·
IF 2.813
Xi Zhou,Huiqin Wu,Xiaolan Huang,Fang Hang,Huitai Luo
This study established a simple and rapid method for simultaneous determination of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in human serum by high performance liquid chromatography coupled with electron spray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF/MS). A simple pretreatment procedure of protein precipitation by acetonitrile coupled with liquid-liquid extraction by n-hexane was employed for extraction and purification . The purified samples were separated by a PFP chromatographic column. This method could effectively eliminate the matrix effect by lipids and other matrix substances in serum samples with less time and solvent consuming. 76 congener groups of SCCPs and MCCPs with C 10 -C 17 and Cl 5 -Cl 13 were quantified by their [M-H] − ions. Method detection limit (MDL) were 1.0–8.0 ng mL −1 for ∑SCCPs and ∑MCCPs. Recoveries were 98.4 ± 4.42%, 98.8 ± 3.96% and 90.7 ± 2.79% for SCCPs and 93.1 ± 6.67%, 108 ± 1.21% and 90.8 ± 3.78% for MCCPs at spiking concentrations of 20, 50 and 200 ng·mL −1 , respectively. The relative standard deviations (RSDs) of intra- and inter-day variations were 1.41% and 9.84% for SCCPs, and 4.23% and 6.26% for MCCPs. The suitability of the developed method was demonstrated through the application to analysis of SCCPs and MCCPs in human serum samples.
研究领域:
环境科学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Materials
·
2022
·
IF 3.985
Long Biyu,Zhou Xianzi,Cao Huafeng,Chen Renjie,He Nannan,Chi Lina,Fan Penghui,Chen Xiaohong
Superior encapsulation technology is important for PSCs to prolong their lifetime and realize their commercial application. Paraffin/EVA/paraffin composite encapsulated layers were fabricated with the ambient environment under the thermal temperature of 80°C, which has advantages for simple procedures and low cost. PSCs encapsulated with paraffin/EVA/paraffin and pure EVA layers maintained 95 and 45% of the initial power conversion efficiency (PCE) aged for 1000 h at RH 75%, respectively. Paraffin/EVA/paraffin-encapsulated PSCs were immersed in water for 5 h, which remained 98% of the original PCE, which is far superior to EVA-encapsulated PSCs. High melting point paraffin at 68°C shows better encapsulation than low melting point (60 and 55°C) paraffin, indicating that the high molecular weight of paraffin helps improve the encapsulation performance of PSCs. PSCs encapsulated with paraffin/EVA/paraffin showed better stability of Voc than pure EVA layer because paraffin can inhibit defects, voids, and edges of metal electrodes that quickly expand, and decay. Therefore, paraffin/EVA/paraffin combination encapsulation is an effective strategy, which can form continuous and dense hydrophobic composite encapsulation films with a friendly metal electrode.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 4
·464
·
IF 3.236
Wei Wang,Liping Shi,Chengcheng Wu,Qi Pan,Hua Fang,Jianwei Jiang,Xueyong Guo
In order to reduce the mechanical sensitivity of ε-CL-20, wax and fluororubber polymers were used as coating materials and desensitizers to coat ε-CL-20 by the water suspension method. Through molecular dynamics calculations, fluorine rubber F2311, which had a good combination with ε-CL-20, was selected as the coating material and then ε-CL-20-based composite particles with double-layer structure were prepared. The contact angles of water, glycerin and diiodomethane as the testing liquids on the surface of F2311and wax were measured by a contact angle measuring instrument, and the thermodynamic parameters of ε-CL-20/F2311and the ε-CL-20/wax interface were calculated. ε-CL-20 before and after coating was characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and the mechanical sensitivity analytical method. The results showed that F2311/wax had uniformly passivated on the surface of ε-CL-20, forming a dense and uniform protective film, and the CL-20 crystal form did not change after coating. The double-layer composite structure effectively reduces the sensitivity of ε-CL-20 and improves the thermal stability of ε-CL-20.Keywords:ε-CL-20;F2311/wax;mechanical sensitivity
研究领域:
材料科学
·
爆炸化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Chuangchuang Zhang,Mengting Ma,Yijuan Xu,Zekun Xu,Zhongquan Sui,Harold Corke
This study compared blending effects of native and octenyl succinic anhydride (OSA) modified blends (waxy rice and waxy potato starch). OSA groups were observed to be present primarily in the outer layer of waxy potato starch granule, but throughout the whole waxy rice granule. A high linear correlation with blending ratio was observed for trough viscosity and final viscosity of native blends, but for peak viscosity (PV) and breakdown viscosity (BD) of esterified blends. PV and BD of esterified blends showed weaker non-additive effects than those of native blends. Consistency coefficient in downward curve, flow behavior index in downward curve, and loss tangent mainly showed non-additive effects in native blends, but additive effects in esterified blends. OSA modification affects interaction between molecules on the outer surfaces of two starch granules by altering molecular structures on the outer surfaces, resulting in different blending effects between native and esterified waxy starch blends.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Peng Bao,Su Jiang,Yang Chen,Yuanlin Fan,Yaning Li,Boliang Wang
Despite the extensive researches on CL-20 crystals, the mechanical safety issues and process problems of CL-20 applications have not been studied in-depth. Herein, the cellulose nanocrystals (CNC) was doped in microcrystalline wax (MW), oxidized microcrystalline wax (OMW) and hydrogel (PPC) to design and fabricate the cross-linked CL-20 composites by simple water-suspension melting and freeze-drying methods. The composites were characterized by SEM, XPS, TG-DSC, XRD, mechanical sensitivity device and inclined chute tester. It is found that the CNC@OMW composite film exhibits excellent coating effect (99.96%) on CL-20 due to the cross-linking results. The E a of CL-20 is increased from 190.92 to 388.71 kJ/mol under the synergistic effect of the excellent compatibility between components and the compact coating structure of CNC@OMW. Additionally, the film enhances the T p0 of CL-20 from 218.15 to 222.66 ℃ and T b from 220.27 to 223.73 ℃, respectively. While, the PPC@CNC only promoted E a , T p0 and T b of CL-20–292.89.71 kJ/mol, 224.22 ℃ and 225.66 ℃, respectively. Besides, the XRD results confirms that three composite films dose not cause a transformation of the ε- CL-20 crystal phase. Most importantly, the cross-linked film brings mechanical sensitivity of CL-20 from 60 N and 3.5 J to a level of over 360 N and 10.4 J, comparable to WO 3 /Al nanothermite with 5 wt% polyaniline (360 N) and composite with 95 wt% LLM-105 and 5 wt% ternary (11–12 J). This improvement enables the composite explosives to be handled using standard procedures. Furthermore, the ability of the particles to accumulate electrostatic charge after cross-linking coating is significantly reduced, and PVC is more suitable as the contact material of CL-20 and composite particles than copper for use in the transportation and packaging. These findings can serve as a reference for wide application of CL-20.
研究领域:
材料科学
·
炸药工程
·
化学工程
✓ 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）