CRYSTENGCOMM
·
2017
·Vol. 19
·期 47
·7207-7212
·
IF 3.474
Zhiyan Chen,Yabo Zhu,Jia Lei,Wanying Liu,Yunke Xu,Peizhong Feng
In the preparation of black phosphorene (BP) by means of low-pressure mineralization, the complex temperature program makes the synthesis mechanism complicated and confusing. Herein, orthorhombic BP crystals were successfully synthesized by low-pressure mineralization and the phase transitions at every stage were revealed systematically and were accurately confirmed via a series of interference experiments and supported by structure characterization. Additionally, the nucleation agents and nucleation sites were systematically investigated. Based on this, we found that the synthesis of BP is a process of stage-by-stage phase-induction. At first, red phosphorus (RP) is transformed to Hittorf's phosphorus (HP) without the assistance of mineralizers. Subsequently, HP is transformed into BP at the cooling stage. Moreover, Sn24P19.3I8 should work as the sole nucleation agent, and leads to BP crystal nucleation and growth to form large crystals in the subsequent heat preservation stage. Also, the nucleation site lies in the product region opposite the source region. In addition, the radial morphology of the BP crystal bunches under an RP/SnI4/Sn (granule) system was revealed firstly, and taking the straps out from the BP bunches is convenient for exfoliating.
研究领域:
材料科学
·
凝聚态物理
·
纳米技术
·
晶体生长
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 136
·期 6
·2363-2371
·
IF 2.209
Zhang Yue-Fei,Lin Xiang-Feng,Chen Shuai
A highly efficient compound nucleating agent of carboxylated graphene/calcium pimelate (Gra/CaPi) for isotactic polypropylene (iPP) was prepared. The structure of Gra/CaPi was investigated by Fourier-transform infrared spectroscopy. The effects of Gra/CaPi on the crystallization and melting behaviors and crystalline morphology of iPP were investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. The results showed that CaPi and Gra were combined by chemical bonds, improved the dispersibility and nucleation ability of Gra in iPP. When the addition amount of Gra/CaPi in iPP was 0.3 mass%, the crystallization peak temperature was increased by 8.0 °C and the relative content of β -crystal in iPP reached up to 0.868 compared with that of pure iPP.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Lu-Lu Yang,Xue-Wei Wei,Tianyu Wu,Hai-Mu Ye
Self-assembled nucleating agents based on hydrogen bonding interactions have been increasingly used to manipulate the crystallization behavior of polymer materials, yet the specific working mechanism is not well unrevealed. In this study, hydrazide-based nucleator structure of bis -(mono-methyl succinyl)dihydrazide (MSAD) is randomly incorporated in poly(butylene succinate) (PBS) chains to prepare a series copolymers of PBS- co -MSAD. It is confirmed that the multiple hydrogen-bonding interactions strengthen as the content of the MSAD segment increases, leading to a remarkable elevation of crystallization temperature. Meanwhile, the primary nucleation density of PBS is significantly raised without changing crystal modification. The formation of pre-ordered network of hydrogen-bonding structures during non-isothermal crystallization is confirmed by rheological measurement and Fourier transform infrared spectroscopy investigation, which immediately induces the crystallization of PBS segments once strong enough. In addition, the melt crystallization mechanism of PBS- co -MSAD with heterogeneous hydrogen-bonding segments is in detail elucidated by combining a self-nucleation protocol.
研究领域:
高分子科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Dequan Han,Huhu Tian,Lantao Liu,Luya Cao,Hongzhang Cao,Xiaoli Yu
The prevalent use of disposable plastic tableware presents notable environmental and health risks. An alternative, polylactic acid (PLA), often does not meet usage requirements due to its low crystallization rate. This research introduces an amide-based nucleating agent, BRE-T-100, developed through a straightforward method to enhance the heat resistance and crystallization rate of PLA. This study systematically investigates the impact of BRE-T-100 and other nucleating agents on the properties of PLA composites. The incorporation of 0.8 % BRE-T-100 increases the crystallization temperature of PLA from 109.6 °C to 131.9 °C. Further, the total crystallization time of PLA composites at 120 °C is reduced to <60 s, while maintaining good transparency. BRE-T-100 exhibits superior comprehensive properties compared to talcum, TMC-200, and TMC-300 and is nearly on par with LAK-301. Its application as a nucleating agent in PLA-based disposable tableware shows promise.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2021
·Vol. 13
·期 17
·2931
·
IF 4.329
Wanxin Peng,Jian Kang,Xiuduo Song,Yue Zhang,Bo Hu,Ya Cao,Ming Xiang
The effects of MXene on the crystallization behavior of β-nucleated isotactic polypropylene (iPP) were comparatively studied. The commonly used MXene Ti3C2Txwas prepared by selective etching and its structure and morphology were studied in detail. Then MXene and a rare earth β-nucleating agent (NA) WBG-II were nucleated with iPP to prepare samples with different polymorphic compositions. The crystallization, melting behavior, and morphologies of neat iPP, iPP/MXene, iPP/WBG-II, and iPP/MXene/WBG-II were comparatively studied. The crystallization behavior analysis reveals that a competitive relationship exists between MXene and WBG-II when they were compounded as α and β nucleating agents. In the system, the β-nucleation efficiency (NE) of WBG-II is higher than α-NE of MXene. The β-phase has relatively low thermal stability and would transform to α-phase when cooled below a critical temperature.Keywords:isotactic polypropylene;MXene;β-nucleating agent;polymorphic crystallization behavior
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2021
·
IF 4.833
Yue Xu,Yong Qiu,Chentao Yan,Lubin Liu,Miaojun Xu,Baoti Xu,Bin Li
In engineering application area, it has always been a challenge to simultaneously improve flame-retardant performance and crystallization rate of polylactic acid (PLA) biomaterials, thus restricting their extensive application. In this work, a multifunctional additive (4,4′-(phenylphosphoryl)bis(piperazine-4,1-diyl))bis(diphenylphosphine oxide) (PDPO) was successfully synthesized and used to fabricate flame retardant PLA biocomposites. The crystallization behavior, fire safety, mechanical properties and flame retardant mechanisms of PLA biocomposites were studied in detail. The results indicated that PDPO notably improved the crystallization rate and crystallinity of PLA biocomposites. When 4 wt% PDPO was incorporated, PLA/PDPO biocomposites successfully passed UL-94V-0 grade and their LOI values were improved from 19.0% of pure PLA to 29.4%. The introduction of PDPO promoted the premature degradation and carbonization of PLA substrate, and inhibited the transesterification of the PLA during thermal pyrolysis process. Besides, PDPO decomposed and produced the Ph and PO , which efficiently exerted the free radical trapping effect in vapor phase. Therefore, the spread of fire for PLA/PDPO was declined and even self-extinguished. Meanwhile, the low addition of PDPO presented little effect on the mechanical properties of PLA composites. This flame retardant PLA biocomposites showed broad application prospects in emerging fields such as electronic devices, automobiles, and 3D printing materials.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Crystallization
·
2020
·Vol. 3
·期 3
·e10125
·
IF 0
Rong Yang,Hongwei Cao,Weilong Chen,Lv Ding,Li Chen,Xin Zhang,Jinchun Li
Polymeric β-nucleating agents (β-NAs) have the advantages of good thermal stability, low toxicity, and relatively superior compatibility with isotactic polypropylene (iPP). However, endowing polymeric β-NAs with high efficiency remains a challenge. Herein, we report a strategy that incorporates ionic monomers into polymeric β-NAs to significantly enhance their nucleation efficiency. Sodium dimethyl 5-sulfonatoisophthalate, an ionic monomer, is introduced into a liquid crystalline polyester NA (PBDPS), and the resulting ionomer is named PBDPSi. The attractive interaction between the ion pairs acts as physical crosslinks and stabilizes the active nucleation center of the ordered benzene rings. Moreover, the ionic monomer modifies the viscosity of the liquid crystalline NA and improves the dispersibility of PBDPSi in the iPP matrix. In addition, it enhances the relative growth rate of β-spherulites of iPP. When 5% sulfonate monomer is introduced into the NA, PBDPSi exhibits the optimal β-nucleation effect, and the maximum value (0.97) of the relative content of β-iPP crystals ( k β ) is obtained. Compared with PBDPS, PBDPSi shows better β-nucleation performance, especially at low concentrations. The incorporation of 0.1 wt% PBDPSi into iPP provides a k β value of 0.41, which is almost four times that obtained with PBDPS.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Yongqi Feng,Piming Ma,Pengwu Xu,Ruyin Wang,Weifu Dong,Mingqing Chen,Cornelis Joziasse
The effects of six nucleating agents (NAs), i.e., orotic acid (OA), potassium salt of 3,5-bis(methoxycarbonyl)benzenesulfonate (LAK-301), substituted-aryl phosphate salts (TMP-5), talc (TALC), N' 1 , N' 6 -dibenzoyladipohydrazide (TMC-306) and N 1 , N 1′ -(ethane-1,2-diyl)bis( N 2 -phenyloxalamide) (OXA), on the crystallization behavior of poly(lactic acid) (PLA) were compared by DSC . Under the same dosing of 0.5 wt%, the nucleation effect of the NAs for PLA declines in the order of TMC-306 ≈ OXA > TALC ≫ TMP-5 ≈ LAK-301 ≈ OA. The nucleation efficiency (NE) of TMC-306 and OXA is around 50%, which is almost 2 times of the NE of TALC. In the best case of the PLA/TMC-0.5% sample, the half-time of crystallization decreases from 30 s to 9 s with decreasing the crystallization temperature from 120 °C to 100 °C, which is of great significance to the fast production of highly crystallized PLA materials. As high-efficient NAs, TMC-306 and OXA are able to accelerate the crystallization rate of PLA even upon fast cooling at 50 °C/min, while make no difference on PLA crystal form, as identified by WAXD . DMA analysis shows that the storage modulus of PLA is significantly improved by TMC-306 and OXA.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainability
·
2021
·Vol. 13
·期 20
·11144
·
IF 3.251
Wei Zhao,Xiaofeng Huang,Bingji Yan,Shaoyan Hu,Hongwei Guo,Dong Chen
Diopside-based glass-ceramics are successfully produced by recycling blast furnace slag and fluorite tailing with the addition of supplementary elements such as TiO2, Fe2O3and Cr2O3as nucleation agents, using a conventional melting method. The effects of various nucleating agents on the phase components and structure of the prepared glass-ceramics were evaluated by a differential scanning calorimeter, X-ray diffraction and scanning electron microscope–energy disperse spectrometer methods to determine the optimal dosage of nucleating agents. The results show that, in the preparation of diopside-based glass-ceramics, the suitable percentages of blast furnace and fluorite tailing are 55% and 45%, and the recommended composite nucleating agents consist of 1.5% Cr2O3, 2% TiO2and 3% Fe2O3. Heat treatment was conducted at a nucleation temperature of 720 °C and a crystallization temperature of 920 °C, and the nucleation and crystallization durations were 1.0 h and 1.5 h, respectively. Under the abovementioned parameters, the obtained diopside-based glass-ceramics displayed a Vickers hardness of 7.12 GPa, density of 2.95 g·cm−3, water absorption of 0.02%, acid resistance of 0.23% and alkali resistance of 0.02%.Keywords:blast furnace slag;fluorite tailing;diopside;glass-ceramics;nucleating agent
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 23
·
IF 1.768
Zhongfei Qi,Yong Yang,Zhu Xiong,Jun Deng,Ruoyu Zhang,Jin Zhu
A series of aliphatic diacyl adipic dihydrazides (ADHs) with different alkyl moieties were synthesized by the reaction between adipic dihydrazide and acyl chloride. Then these ADHs were solution blended with PLA respectively and were evaluated as nucleating agents. Through the investigation of nonisothermal and isothermal crystallization, it was found that both the crystallization rate and the crystallinity of PLA could be enhanced by adding only 1 wt % of ADHs. Especially for ADH-Oc (ADH-Octyl), the crystallization rate of PLA increased about 4 times at 105°C. Optical morphology showed that and the size of PLA spherulites decreased and the nucleation density increased with the existence of ADH-Oc. Meanwhile, the crystal structure of PLA were not discerniblly affected after the addition of ADHs as found by wide-angle X-ray diffraction. Thus, this study suggested these ADHs compounds are simple and potential nucleating agents to enhance crystallization ability of PLA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42028.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2017
·
IF 0
Yijun Li,Xinyu Wen,Min Nie,Qi Wang
Dendritic β-nucleating agent (β-NA) can readily manipulate the formation of dendritic β-crystal with a unique toughening effect on polypropylene (PP) to drastically enhance the ductility. However, by the current method, the geometric size is too large to fully perform the nucleating efficiency. In this study, by comparatively investigating the effect of molecular weight of PP and diffusion of β-NAs in a PP melt, we proposed a novel carrier strategy that selective enrichment of β-NAs in a PP carrier was followed by directed migration into polymer matrix. Accordingly, the growth of NAs was controlled by the release from the PP carrier, which decreased the available amount of β-NAs during the growth stage. In this case, the viscosity difference between PP carrier and matrix determined the interfacial movement of β-NAs. When the PP carrier and matrix had same molecular weight, the diffusion and release became favorable to facilitate the formation of the dense and fine dendritic aggregates. As a result, the relative content of β-crystals reached 92%, with a drastic increase of ∼82% in the optimal condition compared to the directed compounded PP/β-NAs sample. This study can open a new avenue to tailor the topologies of β-NAs and the ensuing β-crystals for high-performance PP products.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
Nanomaterials
·
2023
·Vol. 13
·期 14
·2064
·
IF 5.3
Qin Yang,Zhenkun Zhang,Lin Wang,Xiwen Xing,Jiahai Zhou,Long Li
Modifying crystallization plates can significantly impact the success rate and quality of protein crystal growth, making it a helpful strategy in protein crystallography. However, appropriate methods for preparing nano-sized particles with a high specific surface area and strategies for applying these nanoparticles to form suitable coatings on crystallization plate surfaces still need to be clarified. Here, we utilized both an ultrasonic crusher and a high-pressure homogenizer to create a nano metal–organic framework (MOF), specifically HKUST-1, and introduced a solvent evaporation method for producing MOF coatings on 96-well crystallization plates to induce protein crystal growth. The morphology of MOF coatings on the resin surface of the plate well was characterized using optical and scanning electron microscopy. Compared to the control group, crystallization screening experiments on nine proteins confirmed the effectiveness of plates with MOF coatings. Applying MOF coatings to crystallization plates is an easy-to-use, time-efficient, and potent tool for initiating crystallization experiments.Keywords:protein crystallization;crystallization plates;nucleant;metal–organic framework;coatings
研究领域:
结构生物学
·
生物化学
✓ 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）