Article
Polymer Science
Xiangning Wen, Yunlan Su, Shaofan Li, Weilong Ju, Dujin Wang
Summary: The study demonstrated that PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix, affecting the crystalline morphology and rate of PEO. The good dispersion of PEG-g-SiO2 in the PEO matrix contributes to enhancing the primary nucleation rate.
Article
Polymer Science
Xiang Liu, Wen-Zhi Cui, Wei Yu
Summary: The presence of silica nanoparticles in poly(epsilon-caprolactone) (PCL) leads to significant melt memory effects during slow isothermal crystallization, as demonstrated by differential scanning calorimetry (DSC) and polarized light microscopy (PLM) measurements. The magnitude of the melt memory effects increases with the addition of silica nanoparticles, but the relationship is non-monotonic depending on the type of nanoparticles and their loadings. The influence of silica on nucleation and crystal growth is influenced by the spatial inhomogeneity of chain entanglements in the silica-filled PCL system.
CHINESE JOURNAL OF POLYMER SCIENCE
(2022)
Article
Thermodynamics
Irena Kresic, Natasa Stipanelov Vrandecic, Matko Erceg, Zoran Grubac, Mia Galic
Summary: This study focuses on the characterization of a series of solid nanocomposite polymer electrolytes consisting of PEO, POSS, and LiBOB. The addition of LiBOB and POSS leads to a decrease in the crystallinity and melting temperatures of PEO, while the glass transition temperatures increase. The thermal stability of the polymer electrolytes was investigated, showing a more complex degradation compared to pure PEO. However, the polymer electrolytes remain thermally stable enough for their applications in electrochemical devices. The incorporation of LiBOB and POSS positively influences the ionic conductivity of PEO. The optimized system was determined based on the ionic conductivity of the nanocomposites.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Chemistry, Multidisciplinary
Wei Zhang, Hongbin Zhang, Liping Yang, Yi Tang, Ping Tang
Summary: Incorporating zeolites into Poly(ethylene terephthalate) (PET) can improve its low crystallization rate and long molding cycle. Among the PET/zeolite nanocomposites, PET/MCM-22P exhibits significantly improved crystallization behavior, thermal stability, and oxygen barrier properties, attributed to the layered morphology of MCM-22P and hydrogen bond interactions between MCM-22P and PET.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Polymer Science
Wei-Tao Huang, Guang-Jian He, Wen-Dong Tang, Xin-Liang Zou, Xiao-Chun Yin
Summary: A synergic strategy combining chemical nucleation with chain extension was employed to enhance the crystallization and mechanical properties of PET composites. Sodium linoleate as a nucleating agent effectively promoted the crystallization behavior of PET, while the ultraviolet-induced chain extension method helped maintain the molecular weight of PET.
POLYMER DEGRADATION AND STABILITY
(2021)
Article
Polymer Science
Kamlesh Bornani, Md Anisur Rahman, Brian Benicewicz, Sanat Kumar, Linda Schadler
Summary: Polyethylene-grafted nanoparticles exhibit different assembly states in a polydisperse polyethylene melt based on graft density and molecular weights of the graft chains. The nucleation rate is suppressed with good NP spatial dispersion but accelerated with poorer dispersion due to formation of NP assemblies. The growth kinetics in nanocomposites are retarded, with the agglomeration state of the NPs directly impacting matrix viscosity and growth rates.
Article
Thermodynamics
Wei Gao, Yufeng Li, Jitao Zhao, Weiwei Tang, Zhe Zhang, Jun Wang, Zhenyu Wu, Minggang Li
Summary: PET/graphene oxide (GO) composites were synthesized to overcome the low crystallization rate and long molding time of PET. The influence of GO on the crystallization performance of PET was investigated, and it was found that GO raised the crystallization temperature and rate of PET. The mechanism of PET nucleation induced by GO was studied, and the addition of GO improved the thermal stability of PET.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Polymer Science
Dimitrios G. Papageorgiou, Irini Tsetsou, Raphael O. Ioannidis, George N. Nikolaidis, Stylianos Exarhopoulos, Nejib Kasmi, Dimitrios N. Bikiaris, Dimitris S. Achilias, George Z. Papageorgiou
Summary: This study investigated the structure, thermal properties, and miscibility of PET/PEF blends, finding that the miscibility varied at different blend compositions and exploring reactive blending as a potential method to improve miscibility.
Article
Polymer Science
Pratick Samanta, V Thangapandian, Rajiv Srivastava, Bhanu Nandan
Summary: This study investigates the non-isothermal crystallization kinetics of confined polymer in electrospun nanofibers. The results indicate that the Avarmi and Jeziorny models successfully predict the nucleation nature and growth behavior of PEO chains, while the Ozawa model is not suitable for the confined system. The Mo's method effectively describes the non-isothermal crystallization behavior of PEO in confined domains. The Kissinger and Takhor methods demonstrate that the activation energy for crystallization of PEO chains increases with reduction of PEO weight fraction in the nanofibers.
JOURNAL OF POLYMER RESEARCH
(2022)
Article
Polymer Science
Chunfeng Jia, Shanshan Zhou, Zhanghua Xie, Lukai Wang, Yubin Yang, Xiaoyu Sun, Yuhong Xie, Jinjun Yang
Summary: The P- and Zn-containing organic/inorganic hybrid layered metal phosphonate (PPZn) acted as a biocompatible nucleator in biodegradable poly(ethylene succinate) (PES) polyester, significantly enhancing its crystallization rate and thermal stability. The nucleation was mainly attributed to good crystal lattice matching between PES and PPZn, which facilitated uniform dispersion.
POLYMER INTERNATIONAL
(2021)
Article
Polymer Science
Maria E. Taverna, Abdullah S. Altorbaq, Sanat K. Kumar, Jorge L. Olmedo-Martinez, Carlos A. Busatto, Manuela Zubitur, Agurtzane Mugica, Veronica V. Nicolau, Diana A. Estenoz, Alejandro J. Muller
Summary: This study examines the influence of lignin nanoparticles (LNPs) on the crystallization kinetics of poly(ethylene oxide) (PEO). The results show that the incorporation of LNPs exponentially increases nucleation density, but decreases the spherulitic growth rate. Overall, the nanocomposites exhibit faster crystallization rates compared to neat PEO, suggesting that the supernucleation effect of LNPs dominates over the decrease in growth rates.
Article
Polymer Science
Feng Zhang, Zhiguo Jiang, Zhaobin Qiu
Summary: In this study, biobased poly(ethylene succinate)-b-poly(triethylene terephthalate) (PES-b-PTEGT) multiblock copolyesters with low weight ratios of PTEGT segment were successfully synthesized using a chain extension reaction. The thermal, crystallization, and mechanical properties of PES-b-PTEGT were systematically investigated and compared with those of PES prepared via the chain extension method. PES-b-PTEGT exhibited high melting temperature, enhanced crystallizability, and improved mechanical property.
Article
Polymer Science
Xiangning Wen, Yunlan Su, Guoming Liu, Shaofan Li, Alejandro J. Muller, Sanat K. Kumar, Dujin Wang
Summary: The correlation between the dispersion quality of PEG-grafted silica nanoparticles and the crystallization ability of PEO nanocomposites was systematically investigated, revealing that high sigma and low P/N conditions can increase the nucleation rate of PEO. This study highlights the importance of nanoparticle dispersion and grafting characteristics in influencing the crystallization behavior of polymer nanocomposites, leading to novel and unexpected results.
Article
Materials Science, Multidisciplinary
Jingqun Liu, Chaohui Wang, Yujing Chen, Qiaofeng Lan
Summary: Despite extensive efforts in studying polymer crystallization, the microscopic mechanisms of crystal nucleation are still not well understood. In this study, the crystal nucleation of poly(L-lactide) under high supercooling was investigated using various techniques. The results revealed a multi-step nucleation pathway involving the formation of metastable intermediate phases. These intermediate phases possessed distinct intermediate orders and gradually transformed into the nascent crystalline phase. The findings provide insights into the crystal nucleation mechanisms under large supercooling and have implications for understanding the crystallization of synthetic polymers.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Ce Mi, Yufei Dong, Shaojuan Wang, Huihui Li, Lei Zhu, Xiaoli Sun, Shouke Yan
Summary: A simple heating-cooling procedure is used to fabricate pure polar gamma-PVDF thin films. The pure gamma crystals are induced by controlling the relaxation state of the crystals, through self-seeding and self-nucleation mechanisms within 30 minutes. This methodology provides a new pathway for the application of PVDF homopolymers in flexible ferroelectric devices.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yang-yang Zhao, Yu Cao, Giuliano Siligardi, Georg H. Mehl, Feng Liu, Goran Ungar
Summary: We report the formation of a 3D body-centred self-assembled superlattice of gold nanoparticles with adjustable plasmonic properties exclusively in the xy-plane due to their anisotropic packing. The gold nanoparticles are coated with ligands containing two mesogens, which allows for reversible melting of the superlattice through UV-induced photo-isomerization with low fatigue on repeated cycling.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Engineering, Manufacturing
Yeon Ju Kwon, Youn Kim, Young-Pyo Jeon, Jin-Yong Hong, Ho Seok Park, Jea Uk Lee
Summary: The development of miniaturized and highly integrated microelectronic products has highlighted the need for heat-dissipation materials with high thermal conductivity and electrical insulation. In this study, a hybrid powder Al@EEG was synthesized using planetary ball milling, providing thermal conductivity and electrical insulation to polymer composites for thermal management of electronics.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2022)
Article
Multidisciplinary Sciences
Ya-xin Li, Hong-fei Gao, Rui-bin Zhang, Kutlwano Gabana, Qing Chang, Gillian A. Gehring, Xiao-hong Cheng, Xiang-bing Zeng, Goran Ungar
Summary: A 3D-ordered liquid crystal phase with complex Fddd structure can be formed by spontaneous self-assembly of bent- and straight-rod molecules. This structure allows close packing of fluorescent groups, reducing their bandgap and giving them promising light-emitting properties.
NATURE COMMUNICATIONS
(2022)
Article
Biochemistry & Molecular Biology
Joonwon Bae, Gyo Eun Gu, Yeon Ju Kwon, Jea Uk Lee, Jin-Yong Hong
Summary: As the importance of controlling radioactive materials increases, the development of functional materials for decontamination is becoming crucial. In this study, a three-dimensional porous carbon monolith functionalized with Prussian blue particles was prepared by removing colloidal silica particles from exfoliated graphene/silica composite precursors. The material showed a unique surface and pore structure and was effective in adsorbing hazardous radioactive substances. Various characterizations confirmed the successful incorporation of PB nanoparticles. Adsorption tests demonstrated that the functionalized porous carbon monolith had a higher adsorption capacity compared to the pristine porous carbon monolith and bulk PB for various radioactive ions. This material has potential applications in decontamination.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Yu Cao, Tianyi Tan, David M. Walba, Noel A. Clark, Goran Ungar, Chenhui Zhu, Lei Zhang, Feng Liu
Summary: In this study, the relationship between the helical pitch of the helical nanofilament phase formed by the bent-core molecule NOBOW and the concentration of achiral dopants 5CB and octane was investigated using linearly polarized resonant soft X-ray scattering (RSoXS). The results showed that the variation of the helical pitch is related to the concentration of 5CB and is not temperature-dependent. Doping rodlike immiscible 5CB led to a shortening of the helical pitch, which was attributed to a change in interfacial tension. This study provides insights into the phase behavior of binary systems and enables control over the pitch length.
Article
Chemistry, Multidisciplinary
Yang-yang Zhao, Yaxin Li, Yu Cao, Georg H. Mehl, Feng Liu, Goran Ungar
Summary: The correlation between the size of nanoparticles, the structure and shape of mesogenic ligands and the ensuing assembly behaviour is not fully understood. In this study, gold nanoparticles of different sizes were synthesized and modified with ligands containing rod-like mesogens. The resulting structures were compared and analyzed, and general rules were derived to assist in designing the soft corona of nanoparticles to achieve desired structures and anisotropy.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Kazuma Hamaguchi, Huanjun Lu, Shota Okamura, Satoshi Kajiyama, Junya Uchida, Shunsuke Sato, Go Watanabe, Yoshiki Ishii, Hitoshi Washizu, Goran Ungar, Takashi Kato
Summary: In this study, a combined experimental and computational approach was used to investigate the self-assembly and reentrant behavior of a single-component thermotropic liquid crystal for dynamically functional materials. A designed mesogenic molecule with an unprecedented sequence of layered smectic phases was synthesized, and it exhibited switching functions due to competition between mesogen stacking and conformational flexibility. Ion-conductive reentrant liquid-crystalline materials, showing multistep conductivity changes, were developed.
Article
Polymer Science
Haohui Huo, Jing Zou, Shu-Gui Yang, Jiaqi Zhang, Jie Liu, Yutong Liu, Yanyun Hao, Hongfei Chen, Hui Li, Chaobo Huang, Goran Ungar, Feng Liu, Zhiyue Zhang, Qilu Zhang
Summary: In this study, novel multicompartment nanoparticles (MCNs) with high stability and cargo loading capacity were developed using crystallization-driven self-assembly (CDSA) method. The MCNs exhibited excellent encapsulation capability for hydrophobic drugs and demonstrated cytocompatibility and dose-dependent cellular uptake and cytotoxicity.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Jiaining Cui, Qilu Zhang, Feng Liu, Shu-Gui Yang, Goran Ungar
Summary: The formation of stereocomplex crystals (SC) is an effective method to enhance the heat resistance and mechanical performance of poly(lactic acid) products. However, the SC crystallization of a high-molecular-weight poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) racemate stops or does not start at high temperatures, leading to the crystallization of homochiral crystals (HC) or an SC-HC mixture on cooling. This phenomenon is caused by the accumulation of the pure enantiomer that is rejected from the SC growth front, which is a result of random compositional fluctuation in the melt. The growth of SC can be resumed at lower temperatures along with the growth of HC, and the problem is mainly in growth rather than nucleation.
Article
Polymer Science
Shu-Gui Yang, Liang-Qing Zhang, Jiaming Cui, Xiang-bing Zeng, Baolin Guo, Feng Liu, Goran Ungar
Summary: This study used two-photon confocal laser microscopy to obtain three-dimensional images of the morphology of poly(lactic acid) after shear-induced crystallization. By doping the polymer with Nile Red, the necessary fluorescence contrast was achieved. The results showed that the shape of the resulting cylindrites, or large-diameter shish-kebabs, was influenced by the shear method used. Additionally, the formation of a row of spherulites was observed during fiber pull, which was attributed to crystallization-induced volume contraction.
Article
Chemistry, Physical
Kazuma Hamaguchi, Huanjun Lu, Shota Okamura, Satoshi Kajiyama, Junya Uchida, Shunsuke Sato, Go Watanabe, Yoshiki Ishii, Hitoshi Washizu, Goran Ungar, Takashi Kato
Article
Chemistry, Multidisciplinary
Xiangbing Zeng, Benjamin Glettner, Ute Baumeister, Bin Chen, Goran Ungar, Feng Liu, Carsten Tschierske
Summary: This study presents a two-dimensional columnar liquid quasicrystal with dodecagonal symmetry, which is different from previous dodecagonal quasicrystals based on random tiling. It observes a honeycomb structure based on a strictly quasiperiodic tessellation of tiles. The stability of this quasicrystal may rely solely on energy minimization, or with minimal entropic intervention.
Article
Chemistry, Multidisciplinary
Ningdong Huang, Weiheng Huang, Zhenlin Luo, Wangsheng Chu, Goran Ungar
Summary: 3D crystalline order with 1 nm resolution is observed in aqueous solutions of supramolecular nanotubes containing 94% water, at concentrations as low as 6 wt%. The nanotubes are formed by supramolecular rings of star-like organic ions, which stack on top of each other to form long hollow tubes with 15 nm outer diameter. The high 3D order is attributed to long-range attraction between like-charged tubes and amplified charge modulation by the extremely high intra-tube correlation length.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Polymer Science
Shu-Gui Yang, Liang-Qing Zhang, Changlong Chen, Jiaming Cui, Xiang-bing Zeng, Liying Liu, Feng Liu, Goran Ungar
Summary: Polymorphism of semicrystalline polymers has a significant impact on their physical properties, but determining the shape, spatial distribution, and volume fraction of different coexisting crystal polymorphs remains a challenge. In this study, 3D imaging using two-photon fluorescence confocal microscopy and synchrotron X-ray beam scanning was employed to visualize and quantify the different crystal forms and their specific morphologies. The ability to distinguish crystal forms and their distributions is demonstrated, providing valuable insights into the processing and properties of semicrystalline polymers.
Article
Chemistry, Multidisciplinary
Virgil Percec, Ning Huang, Qi Xiao, Benjamin E. Partridge, Dipankar Sahoo, Mohammad R. Imam, Mihai Peterca, Robert Graf, Hans-Wolfgang Spiess, Xiangbing Zeng, Goran Ungar
Summary: Programming complex living and soft matter through primary structure and self-organization is key in designing functions in biological and synthetic nanoscience. Memory effects, such as supramolecular orientational memory (SOM), have been utilized in creating commercial technologies and engineering complex nanoscale soft matter. The discovery of SOM in a non-cubic Frank-Kasper phase suggests the potential expansion of this methodology to other periodic and quasiperiodic nanoarrays in soft and living complex matter.
