FUEL
·
2024
·
IF 6.7
Xinjie Sun,Lingli Jia,Xinyuan Li,Shanrong Zhang,Yiting Wang,Mingwang Fan,Jun Xu
Wax precipitation causes numerous challenges in the transportation and refining of crude oil. Wax deposition can be decreased and the flowability of waxy crude oil in cold temperatures can be increased by addition of polymer additives in the crude oil. Sequentially well-structured polymers synthesized by reversibly additive fragment chain transfer (RAFT) polymerization enhance the capability to inhibit the growing of wax crystals. In this paper, star chain-transfer agents (star-CTA) was synthesized by esterifying polyol with a tri-thiocarbonate RAFT reagent. Then, poly octadecyl acrylate-maleic anhydride (POM) copolymers with linear and star structure (3, 4, 6 arms) were synthesized via RAFT polymerization. The chemical structures were then characterized using FT-IR, 1 H NMR and GPC approaches. The effects of star copolymers on wax crystallization and cold flowability were analyzed by DSC, XRD, polarized light microscopy and rheology. The transformation from lamellar to fibrous crystals and a decrease in fractal dimensions of crystal growth upon adding all polymers were observed through kinetics of isothermal crystallization and non-isothermal crystallization (NIC) using DSC. Upon further calculations, the crystallization activation energy of NIC increased from 34.40 kJ/mol to 63.22 kJ/mol with the increase of arms. Revealed by XRD, both of the relative crystallinity index and the grain size of crystals are reduced by polymers. Further, the growth along the x and z axes is suppressed, resulting in fibrous growth. The viscosity initially decreases and then increases as the number of arms of polymer increases, with 4-arms POM (4X-POM) reducing the viscosity by 64.63 %. The present work reveals the mechanism of inhibiting wax crystal growth by star polymers, providing valuable theoretical guidance for the practical application.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
高影响因子
PACKAGING TECHNOLOGY AND SCIENCE
·
2024
·
IF 2.8
Yang Zou,Yanfen Zhang,Hui Zhang,Bin Cao,Zixin Luo,Huawei Duan
Studies have shown that fluoridated reagents for oil and water resistance are harmful to the human bodies and the environment. Consequently, the developments of nontoxic, environmentally friendly, fluorine-free and degradable materials have received increasing attentions. Here, we introduce a novel method for fabricating a hydrophobic and oleophobic paper-based packaging material through the application of chitosan/carnauba wax emulsions. These emulsions were prepared via high-shear homogenization, blending melted carnauba wax with chitosan in acetic acid aqueous solutions. The stable chitosan/carnauba wax emulsion with particle size of 430 nm was prepared at the chitosan concentration of 1.5 wt%, the carnauba wax concentration of 8 wt% and temperature of 85 °C. After 10 g/m 2 of chitosan/carnauba wax emulsion was applied to the paper surface, the oil and water resistance of the paper was significantly improved. The experimental results of kit rating value, oil contact angle, Cobb 60 value and water contact angle were 9.5 ± 0.6, 86.6 ± 2.1°, 8.90 ± 1.62 g/m 2 and 123.5 ± 2.6°, respectively. The application of chitosan/carnauba wax emulsion coating on papers provided a significantly lower water vapour transmission rate (WVTR, 78.45 ± 18.92 g/m 2 ·24 h) and oxygen transmission rate (OTR, 94.26 ± 20.21 g/m 2 ·24 h) as compared to the original paper, which met the needs of strawberry packaging.
研究领域:
材料科学
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环境科学
·
食品科学
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产品关联
DOI
高影响因子
Frontiers in Sustainable Food Systems
·
2024
·
IF 3.7
Wang Nannan,Bao Wei,Gouife Moussa,Xu Jiajie,Han Jiaojiao,Lu Chengyang,Ming Tinghong,Zhou Jun,Zhang Wenwen,Su Xiurong
Background: The fermented wax gourd, often referred to as “smelly wax gourd,” is a traditional food that undergoes natural fermentation. It’s a staple in eastern China and is recognized as Ningbo’s “city-fermented food.” Characterized by its distinct putrid flavor and soft texture, its safety, nutritional aspects, and sensory attributes have not been extensively studied.Methods: In this research, the microbial community and flavor components of fermented wax gourd during its traditional fermentation were analyzed. The safety and impact on the gut microbiota were also assessed by administering it to healthy and pseudo-germ-free mice.Results: The findings revealed that organic acids primarily contribute to the gourd’s flavor during fermentation. The aroma reminiscent of fruits is due to 2-methyl-butyric acid, while butyric, pentanoic, caproic, and octanoic acids are responsible for their characteristic smelly taste. In the fermentation of traditional foods, the abundance of substances and open fermentation contribute to the diversity of microorganisms in the system, and the reproduction and metabolism of microorganisms drive the fermentation of foods. From the results of this study, the flavor peaks on the 10th day of fermentation. Predominant microbes include Lactobacillus fermentum, Streptococcus equinus, Fusobacterium perfoetens, Weissella confusa, and Lactobacillus plantarum. Notably, Lactobacillus was the most abundant probiotic in the early fermentation stages. The “smelly” taste of smelly wax gourd was mainly derived from butyric acid, valeric acid, caproic acid, caprylic acid, p-methylphenol and other compounds, and the abundance of Caldicoprobacter algeriensis, Mariniphaga anaerophila, Streptococcus equi and Lactobacillus were significantly correlated with 4 of the above 5 acids. These four bacteria may contribute more to the “smelly” taste of smelly wax gourd. In the study, compared with the control group (CONT), the abundance of Helicobacter ganmani, H. Chanicola, Lactobacillus animalis, Lactobacillus gadi and Lactobacillus reuteri decreased in mice groups treated with anti-biological pretreatment followed by gavage of smelly wax gourd (A.SWG) and the smelly wax gourd (SWG) groups. Conversely, Muribaculum intestinale, Prevotellamassilia timonensis, Alistipes putredinis, Kineothrix alysoides and Clostridium indolis’ abundance of increases. Mice that underwent fecal microbiota transplantation (FMT) exhibited a higher abundance of probiotics like Bifidobacterium animalis, Bifidobacterium pseudolongum, Lactobacillus johnsonii, and others compared to the fecal culture microbiota transplantation (CMT) group. However, the CMT group had a higher presence of fermented and Royce lactobacilli.Implication: Consuming fermented wax gourd can enhance the presence of beneficial probiotics and reduce pathogenic Helicobacter sp. in the mouse gut. Both Lactobacillus sp. and Bifidobacterium sp. showed increased abundance post fecal microbiota and fecal culture microbiota transplantation.
研究领域:
食品科学
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微生物学
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营养学
·
胃肠病学
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产品关联
DOI
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2020
·
IF 4.303
Mingyi Yang,Zisheng Luo,Sunan Gao,Tarun Belwal,Lei Wang,Ming Qi,Zhaojun Ban,Bin Wu,Fengzhong Wang,Li Li
Plant cuticular wax is the first barrier to resist biotic and abiotic stress. However, little is known about the compositional differences between the epicuticular and intracuticular wax in grape berry. The compositional, morphological and functional features of cuticular wax in grape berries of Vitis vinifera cv. ‘Kyoho’, ‘Muscat Hamburg’, ‘Redglobe’, and ‘Zuijinxiang’ were investigated. The total and epicuticular wax of four berries were mainly composed of terpenoids, hydrocarbons, alcohols, fatty acids and esters. Oleanolic acid was the most abundant terpenoid among the four cultivars. Scanning electron microscopy revealed the crystalline flakes structure of the cuticular wax. Additionally, the removal of epicuticular wax accelerated the weight loss, browning, and softening of grape berries, indicating the plastic-wrap-like effect of the cuticular wax on postharvest quality. This study provided the theoretical basis for further application of the fruit wax or waxy analogue.
研究领域:
植物学
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园艺学
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食品科学
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产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 9
·1786
·
IF 4.967
Dongyang Liu,Yuqing Duan,Shumei Wang,Murong Gong,Hongqi Dai
Studies have shown that fluorinated oil repellents are potentially harmful to humans and the environment, and therefore, the development of non-toxic, green, and environmentally friendly oil repellents has become inevitable. Microcrystalline wax is a branched saturated alkane with a molecular weight of 580–700 Da, which has a lower surface tension than edible oil. Herein, microcrystalline wax emulsion (fluorine-free oil repellent) was prepared by mechanical stirring–homogenization, the effects of emulsifier ratio and dosage on the emulsion performance were systematically investigated, and the resultant stable microcrystalline wax emulsions were applied to the paper surface to explore the oil and water resistance and water vapor barrier performance. The results showed that stabilized microcrystalline wax emulsion was obtained at the emulsifier Span-80/Tween-80 ratio of 5:5, and the emulsifier dosage was 20% (relative to the microcrystalline wax). When 6 g/m2of microcrystalline wax was applied to the surface of starch pretreated paper, the kit rating value of the paper was high, at up to 10/12, the Cobb60value decreased to 12.5 g/m2, the overall migration of paper was less than 10 mg/dm2, and the water vapor permeability was reduced by 81.9%, which met the requirements of oil and water resistance performance of food packaging paper.Keywords:microcrystalline wax emulsion;oil and water resistance;fluorine-free oil repellent
研究领域:
食品科学
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Shikun Tong,Pengfei Li,Fengjun Lv,Zhiyuan Wang,Weiqi Fu,Jianbo Zhang,Litao Chen,Xuerui Wang
Clarifying the effect of wax on hydrate formation and dissociation are important for the safe and high-efficient development of deep-water oil and gas fields. In this study, a series of experiments on the effect of wax on hydrate formation and dissociation in water-in-oil emulsions were systematically studied based on the variation analysis of temperature, pressure, torque, oil–water interface area morphology and water droplet size in emulsions. Microscopic images reveal that wax crystals form shell barriers on the oil–water interface, which increases transfer resistance, and the particle focused beam reflectance illustrates that the wax crystals decrease the water droplet size, which increases the oil–water interface area in emulsions. With increasing wax concentration, the hydrate induction time and growth rate show a bimodal shape because of the dual regulation of wax in emulsions, involving the inhibition effect of the transfer barrier layer and the promotion effect of the increasing water–oil interface area. The inhibition effect on hydrate formation was dominant when the wax concentration exceeds 6 wt%, resulting in a rapid decrease in both the growth rate and conversion ratio with increasing wax concentration. Compared with the bimodal shape of hydrate formation, the inhibition effect of wax on hydrate dissociation is the dominant regulation factor. The duration of complete hydrate dissociation by depressurization increased linearly with the increasing wax concentration, which increased the operation difficulty of hydrate plug removal. These experimental results provide valuable references for hydrate risk assessment and optimization of the project design of flow assurance for deep-water oil and gas fields.
研究领域:
石油工程
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化学工程
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产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Miao He,Dengdeng Xie,Lian Yin,Kaili Gong,Keqing Zhou
It is well known that poor thermal conductivity , easy leakage in melting, and low fire safety will hinder the practical application of phase change materials (PCMs) in energy storage. In this work, a series of graphene aerogels with different reduction degrees were obtained by regulating the reaction temperature and then compounded with paraffin wax to form composite PCMs. Satisfactorily, the composite PCMs not only showed a considerably improved shape stability compared to pure paraffin wax, but also an improvement in thermal conductivity from 13.56% to 44.44% with the increase of reduction temperature. Besides, the composite PCMs exhibited promising thermal stability and flame resistance. The peak heat release rate of the composite PCMs decreased by 27.5%, 32.1% and 41.3% respectively as the reduction temperature increased. More importantly, the composite PCMs had outstanding photothermal conversion capability, and the temperature of the composite phase change material could rise from 20 ℃ to 63 ℃ after absorbing light for 4 min. Overall, the increase of the reduction temperature of graphene aerogel has an outstanding contribution to improving the energy storage performance and thermal properties of the composite PCMs.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Hua Huang,Hailun Liu,Ling Wang,Xu Xiang
Litchi fruit is susceptible to pericarp browning, which is largely due to the oxidation of phenols in pericarp. However, the response of cuticular waxes to water loss of litchi after harvest is less mentioned. In this study, litchi fruits were stored under ambient, dry, water-sufficient, and packing conditions, while rapid pericarp browning and water loss from the pericarp were observed under the water-deficient conditions. The coverage of cuticular waxes on the fruit surface increased following the development of pericarp browning, during which quantities of very-long-chain (VLC) fatty acids, primary alcohols, and n -alkanes changed significantly. Genes involved in the metabolism of such compounds were upregulated, including LcLACS2 , LcKCS1 , LcKCR1 , LcHACD, and LcECR for elongation of fatty acids, LcCER1 and LcWAX2 for n- alkanes, and LcCER4 for primary alcohols. These findings reveal that cuticular wax metabolism may take part in the response of litchi to water-deficient and pericarp browning during storage.
研究领域:
植物生理学
·
园艺学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Xin Wang,Jiayi Sun,Shenghan Zhao,Fang Zhang,Xianghong Meng,Bingjie Liu
The objective of this work was to develop nanostructured lipid carriers (NLCs) with preservation effect by using pea protein isolate (PPI) nanoparticles as emulsifiers, candelilla wax (CW) as organo-gelator and d -limonene (DL) as antifungal agent. The optimal formulation parameters of NLCs were firstly determined based on results of particle size, poly-dispersity index and zeta potential, and then NLCs prepared by optimal formulation were further characterized. The results showed that DL was successfully encapsulated inside NLCs. Moreover, the encapsulation of amorphous DL led to more disordered crystalline state of NLCs. In addition, in comparing the properties of NLCs and nanoemulsions (NEs) without CW, it was found that the addition of CW seemed to have several beneficial effects on NLCs: 1) NLC droplets were well dispersed, whereas NE droplets exhibited coalescence and flocculation; 2) compared with NEs, NLCs displayed excellent storage stability and inhibition ability of DL release. Furthermore, antifungal activity of NLCs was observed by in vitro and in vivo study. The acquired information in current research can provide novel insight into development of stable and antifungal nanocarriers that own a promising application in tomato preservation.
研究领域:
药学
·
食品科学
·
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2023
·Vol. 45
·期 4
·3343-3354
·
IF 5.2
Hongyu Liu,Xiaobing Fan,Bingli Pan,Yuxuan Zhou,Longlong Zhang,Menghan Li,Ziying Li,Xinchang Pang
Epoxy composites with simultaneously enhanced tribological and mechanical properties filled with basalt belt/reduced graphene oxide/paraffin wax (EP/BF/RGO/PW) have been successfully prepared. Experimental results indicated that the mechanical property of the composites was reinforced by basalt belt, and the tribological property was greatly improved by reduced graphene oxide/paraffin wax at the same time. Thanks to the synergy of PW and RGO sheets, the optimized coefficient of friction and wear rate of the composite declined by 77.5% and 14.4% than pure EP under dry friction conditions of 60 N and 0.42 m s −1 . In comparison to pure EP, the tensile strength and modulus of the optimized composite increased by 75.5% and 100% on account of the robust basalt fibers. Thus, the combination of basalt fiber and reduced graphene oxide/paraffin wax can readily realize the introduction of enhancer and oil-impregnation in EP, offering a promising approach for simultaneously improving the mechanical and tribological properties of epoxy. Highlights A novel BF/RGO/PW 3D skeleton was developed via a facile hydrothermal method. The BF/RGO/PW can enhance the mechanical and tribological properties of EP. The basalt fibers account for the improvement in mechanical property. A reduction of 77.5% in COF and a decrease of 14.4% in wear rate were realized.
研究领域:
材料科学
·
复合材料工程
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产品关联
DOI
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Guangchun Song,Yuanxing Ning,Yuxing Li,Wuchang Wang
In oil industry, the coexistence of hydrate and wax can result in a severe challenge to subsea flow assurance. In order to study the effects of wax on hydrate growth at the oil–water interface, a series of microexperiments were conducted in a self-made reactor, where hydrates gradually nucleated and grew on the surface of a water droplet immersed in wax-containing oil. According to the micro-observations, hydrate shells formed at the oil–water interface in the absence of kinetic hydrate inhibitor (KHI). The roughness and growth rate of hydrate shells were analyzed, and the effects of wax were investigated. In addition, vertical growth of the hydrate shell was observed in the presence of wax, and a mechanism was proposed for illustration. In the presence of KHI, small hydrate crystals formed separately at the oil–water interface instead of hydrate shells. The presence of KHI reduced the growth rate of hydrates and changed the wettability of hydrates. Moreover, the presence of wax showed no obvious effect on the effectiveness of KHI under experimental conditions.
研究领域:
石油工程
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2026
·
IF 10.4
Yejun Zhong,Ziyi Zhu,Ruiyun Chen,Liqiang Zou,Wei Liu,Shan Sun,Jianyong Wu,Er Sheng Gong
Natural waxes in oil phase enhance structural integrity of W/O/W emulsion gels. • Sunflower wax yields superior probiotic survival during pasteurization and digestion. • Wax-driven oil solidification protects L. plantarum and S. thermophilus effectively. • Novel oil-phase gelled emulsion system advances probiotic delivery in food matrices. This study explored impact of natural waxes (beeswax, BW; rice bran wax, RBW; sunflower wax, SFW)-mediated oil-phase gelling on the physicochemical properties and probiotic-protective efficacy of W/O/W emulsion gel beads co-encapsulating Lactobacillus plantarum and Streptococcus thermophilus . Wax incorporation preserved “two-membrane, three-phase” emulsion architecture while increasing droplet sizes and viscosity, with SFW and RBW yielding denser, more uniform bead microstructures and reduced moisture mobility compared to controls (without wax, NW) and BW. XRD and DSC revealed β’-polymorphic crystals in RBW and SFW, correlating with higher melting points and thermal stability. During pasteurization, simulated gastrointestinal digestion, and 28-day storage in acidic orange juice, SFW beads exhibited superior probiotic viability, with log CFU reductions minimized to 2.6 for Lactobacillus plantarum and 2.0 for Streptococcus thermophilus , versus 3.4 and 3.1 in NW. This approach holds significant promise for improving probiotic encapsulation in functional foods, enabling targeted delivery and extended shelf-life under adverse conditions. Download: Download high-res image (99KB) Download: Download full-size image
✓ 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）