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| 1 | Frank-Kasper and related quasicrystal spherical phases in macromolecules显示文摘Creation of diverse ordered nanostructures via self-assembly of macromolecules is a promising 'bottom-up' approach towards next-generation nanofabrication technologies. It is therefore of critical importance to explore the possibilities to form new self-assembled phases in soft matter systems. In this review, we summarized recent advances on the identification of several unconventional spherical phases in the self-assembly of functional macromolecules, including Frank-Kasper(F-K) phases and quasicrystals originally observed in metal alloys. We believe that these results provide a new strategy towards the rational design of novel functional materials with hierarchically ordered structures. | Mingjun Huang Kan Yue Jing Wang Chih-Hao Hsu Linge Wang Stephen Z.D.Cheng | 2018 | Science China Chemistry2018，61，1： | 2 |
| 2 | Phase Transitions and Structures of Poly(ethylene-co-chlorotrifluoroethylene)显示文摘Poly(ethylene- co -chlorotrifluoroethylene) with a 1∶1 molar ratio of ethylene and chlorotrifluoroethylene in composition, PECTFE, is a statistically alternating copolymer widely used in cable coating industry. PECTFE has been commonly characterized as a semicrystalline polymer with crystals melting at 238 ℃. Differential scanning calorimetry, thermal mechanical analysis and dynamic mechanical analysis indicated that PECTFE undergoes a reversible solid-solid transition during cooling and heating in the temperature range between 100 ℃ and 200 ℃. Based on detailed structural analysis via wide angle X-ray diffraction and electron diffraction techniques, we proposed that PECTFE possesses a hexagonal phase above 200 ℃( a =0 60 nm, c =0 49 nm) and an orthorhombic phase( a =0 99 nm, b =0 57 nm, c =0 49 nm) at room temperature. | J.M.DEITZEL, Bojie WANG, Ping HUANG, L.Lawrence CHAPOY, Stephen Z.D.CHENG * (The Maurice Morton Institute and Department of Polymer Science, The University of Akron,Akron Ohio 44325-3909,U.S.A.) Dedicated to the Occasion of the 80th Birthday of P | 2001 | 应用化学2001，18，5： | 1 |
| 3 | Professor Emeritus Darrell Reneker显示文摘It is with great sadness that we write today to all of you,the polymer and fber community that Darrell H.Reneker dedicated his career to serve,that he passed away on October 17,2021,aged 91.Darrell H.Reneker,Emeritus Professor of Polymer Science at The University of Akron,was the recipient of the 2nd“Qian Baojun”Fiber Award Distinguished Achievement in 2019,for his pioneering work in electrospinning technology,especially the use of this technology to prepare nanofbers.This biennial award was initiated by the State Key Laboratory for Modifcation of Chemical Fibers and Polymer Materials,Donghua University in 2017. | Stephen Z.D.Cheng | 2022 | Advanced Fiber Materials2022，4，1： | 0 |
| 4 | MOLECULAR AND SUPRAMOLECULAR ORDERING IN CONFINED ENVIRONMENTS显示文摘Crystal and phase morphologies and structures determined by self-organization of crystalline-amorphous diblockcopolymers, crystallization of the crystallizable blocks, and vitrification of the amorphous blocks are reviewed through asystematic study on a series of poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymers. On the base ofcompetitions among these three processes, molecular and supramolecular ordering in confined environments can beinvestigated. In a concentration-fluctuation-induced disordered (DCF) diblock copolymer, the competition between crystalli-zation of the PEO blocks and vitrification of the PS blocks is momtored by time-resolved simultaneous small angle X-rayscattering (SAXS) and wide angle X-ray diffraction (WAXD) techniques. In the case of Tc<TgPS-rich, the crystallization of thePEO blocks is observed to be confined within the bicontinuous DCF phase due to the rapid vitrification of the PS-rich phase.Overall crystallization rate, crystal melting behavior, and crystallinity results further confirm the competition betweencrystallization and vitrification at different temperatures. In an ordered lamellar PEO-b-PS diblock copolymer, the crystalli-zation of the PEO blocks is completely confined within the ordered lamellae due to rapid vitrification of the PS layers asobserved by time-resolved SAXS and WAXD experiments. From the combined two-dimensional SAXS and WAXDmeasurements, the crystal orientation within the confined lamellar geometry is found parallel to the lamellar surface normalwhen it is isothermally crystallized at 35℃. In an ordered cylindrical PEO-b-PS sample, the crystallization of the PEO blocksis also observed to be confined within the ordered cylinders because of rapid vitrification of the PS matrix. The crystalorientation within the confined cylinders is found perpendicular to the cylinder axis as it is crystallized at 35℃. | Stephen Z.D.Cheng Bret H.Calhoun Roderic P.Quirk Benjamin S.Hsiao | 2000 | Chinese Journal of Polymer Science2000，18，4： | 0 |
| 5 | Spherical Packing Superlattices in Self-Assembly of Homogenous Soft Matter:Progresses and Potentials显示文摘The construction of complex superlattices using homogenous soft matter has great potential for the bottom-up fabrication of complex,nanoscale structures.This topic is not only interested in scientific exploring for new concepts of supramolecular crystals with nanometer in sizes,which is about thousand times larger in volumes than those of normal crystals,but also practically important to provide construction principles of metamaterials which are artificially structured materials for controlling and manipulating light,sound,and other physical behaviors.These systems have fast assembly kinetics and convenient processing procedures,making them ideal for large-scale superlattice production.In this perspective,we focus on recent developments in the construction of complex spherical packing superlattices using homogenous soft self-assemblies.We discuss the general mechanism of those formations of supramolecular motifs and provide an overview of the spherical packing superlattices self-assembled by homogenous soft matters based on different volume asymmetry.Additionally,we outline the potentials of utilizing this approach in constructing novel superlattices as well as its future challenges. | Yuchu Liu Huanyu Lei Qing-Yun Guo Xianyou Liu Xinghan Li Yuean Wu Weiyi Li Wei Zhang Geng Xin Liu Xiao-Yun Yan Stephen Z.D.Cheng | 2023 | Chinese Journal of Polymer Science2023，41，5： | 0 |
| 6 | Special topic on soft matter science and technology显示文摘Soft matter,as first proposed by de Gennes in 1991,describes a broad range of molecular systems exhibiting a large response to small foreign stimuli.Typically,it includes colloidal particles,amphiphiles,liquid crystals,polymers and others.The term'soft'originates from the common macroscopic properties of these systems and differentiates them from conventional'hard'materials.Over the past decades,the field of'soft matter'has progressed tremendously.Today,it is a truly multidisciplinary research endeavor bridging physics with chemistry and life science. | Wen-Bin Zhang Stephen Z.D.Cheng Yong Cao | 2018 | Science China Chemistry2018，61，1： | 0 |
| 7 | SEMI-QUANTITATIVE CHARACTERIZATION OF SEGMENT DISTRIBUTION IN LLDPE BASED ON THERMAL SEGREGATION显示文摘Based on successive multiple-step isothermal crystallization and self-nucleation annealing methods, a novel semi-quantitative method for the characterization of segment distribution in linear low density polyethylene (LLDPE) wasestablished by treating the thermal analysis data using the Gibbs-Thomson equation. The method was used to describe thesegment distribution of Ziegler-Natta catalyzed LLDPE (Z-N LLDPE), metallocene catalyzed LLDPE (m-LLDPE) and twocommercial LLDPEs with wide molecular weight distribution. The differences of the results obtained from the two thermallytreated samples were compared. The results of segment distribution of the polymers were discussed according to theirmicrostructure data and were compared with their characteristics. It can be deduced from the results that this characterizationmethod is effective to characterize the sequence structure of the branched ethylene copolymers. | Stephen Z.D.Cheng | 2002 | Chinese Journal of Polymer Science2002，20，4： | 0 |
| 8 | Constituent Isomerism-Induced Quasicrystal and Frank-KasperσSuperlattices Based on Nanosized Shape Amphiphiles显示文摘Naturally,subtle variations in the chemical structures of constituent molecules may significantly affect their multiscale spatial arrangements,properties,and functions.Deceptively simple spherical assemblies supply an ideal platform to investigate how subtle chemical differences affect hierarchically assembled structures.Here,the authors report two sets of nanosized shape amphiphiles,which were constructed by a triphenylene core and six polyhedral oligomeric silsesquioxane cages peripherally grafted through linkers.The slight differences in these samples are merely several methylene units in their linkers,including several pairs of constituent isomers.These nanosized shape amphiphiles self-assemble into a variety of unconventional spherical packing structures,which include the Frank-Kasperσphase and dodecagonal quasicrystal.Several types of unconventional phase transitions were systematically investigated.The authors alternated the conventional columnar phases of discotic molecules to unconventional spherical packing phases.These unconventional structures may shed light into discovering discotic mesogens-based materials with new properties and functions. | Zebin Su Jiahao Huang Wenpeng Shan Xiao-Yun Yan Ruimeng Zhang Tong Liu Yuchu Liu Qing-Yun Guo Fenggang Bian Xiaran Miao Mingjun Huang Stephen Z.D.Cheng | 2021 | CCS Chemistry2021，3，5： | 0 |
| 9 | 利用柔性单体构筑液晶高分子显示文摘 通常,液晶高分子都含有被称为液晶基元的刚性成分以维持液晶相的分子取向序。常见的液晶基元含有2个以上对位相连的苯环,如二联苯、苯甲酰氧基苯等。已知聚对苯二甲酸乙二酯不能生成液晶相,而联苯二甲酸乙二酯却是液晶性高分子,其区别即在于前者只含有孤立的苯环而后者则含有可以维持液晶相结构的联苯型液晶基元。不过,液晶相结构除了通过液晶基元稳定外,还可以通过高分子的超分子组装实现。在我们最近开展的一系列研究中已经发现,利用甲壳型液晶高分子设计思想合成的各种聚(乙烯基对苯二甲酸环烷酯)都能生成稳定的热致液晶相,尽管在这些分子中不存在传统意义上的液晶基元(1,2)。本文报告一个以柔性的对苯二甲酸双烷基酯为侧基的聚乙烯,聚(乙烯基对苯二甲酸-4-庚酯)的合成与性质。…… | 涂慧琳 宛新华 刘宇翔 陈小芳 张东 周其凤
Zhihao Shen Jason J.Ge Stephen Z.D.Cheng | 2000 | 厦门大学学报(自然科学版)2000，39，z1： | 0 |
| 10 | WHAT ARE THE DIFFERENCES OF POLYMER SURFACE RELAXATION FROM THE BULK?显示文摘在薄电影的聚合物表面松驰是一个长辩论问题。我们报导聚合物的表面松驰行为变瘦的学习上的一个新方法在稳固的底层上拍摄。这个方法涉及在液体与一个 pretilting 角度利用磨擦 polyimide 表面水晶的房间。由于表面排列,液体晶体沿着磨擦方向被排列。在加热液体期间水晶的房间,我们连续地监视了液体晶体的取向的变化。在液体水晶的取向被失去的温度,玻璃底层上的表面松驰发生失去 polyimide 表面取向,这被理解。液体晶体在失去他们的取向的松驰温度取决于 polyimide 的电影厚度,这被发现。在松驰温度之间的一种量的线性关系并且电影厚度相互能被观察。而且,不同拓扑学磨擦了并且放松薄电影用聚乙烯装饰方法被放大并且遵守了使用原子力量显微镜学。 | Ian Mann Ryan M.Van Horn Jason J.Ge Matthew J.Graham Frank W.Harris Stephen Z.D.Cheng | 2011 | Chinese Journal of Polymer Science2011，29，1： | 0 |
| 11 | TRANSIMIDIZATION IN THERMOPLASTIC POLYIMIDES显示文摘In order to improve the processibility in thermoplastic polyimides, a new method, termed the'reactive plasticizer' approach, has been proposed. This method uses a small amount (5~15 mol%) of a lessactivated, weak nucleophilic diamine co-monomer as a 'reactive plasticizer' to obtain copolyimide resinswhich possess relatively low viscosity at low temperatures and can be readily processed through the autoclavecycle at low pressures. During a high temperature treatment, the reactive plasticizers join the reaction to formhigh molecular weight copolyimides, and the preferred material properties are thus achieved. The mosteffective reactive plasticizer is aromatic heterocyclic diamines, such as 2, 6-diaminopyridine diamine (DAP),and the transimidization involved with a reactive plasticizer has been proposed to play a major role for thesuccess of this approach. In order to understand the transimidization mechanism, three steps have been takenin this research: first, a copolyimide system of 50% of DAP and 50% 1, 4 -bis [4-aminophenoxy] benzenediamine (DODA) with 100% of 2, 2’-bis[4-(3, 4-dicarboxyphenoxy)phenyl] propane dianhydride (UltemRDA) is prepared. Second, several specifically designed polyimide mixture systems were used, and they consistof two homopolyimides: one is UltemR DA-DODA, and the other is UltemR DA-DAP. The third step is toinvestigate two mixture systems in which UltemR DA-DODA is mixed with DAP monomer solution andUltemR DA-DAP is mixed with DODA monomer solution. For all systems, with increasing degree oftransimidization upon heat-treatment, the chain structures of the mixtures and their thermal and dynamicmechanical transition behaviors are investigated via one-dimensional and two-dimensional nuclear magneticresonance, differential scanning calorimetry, and dynamic mechanical analysis experiments. Experimentalresults indicate that in the mixture of two homopolyimides, transimidization takes place much moreefficiently in solution than in the melt. For the two mixtures with monomer solutions, the transimidizationcan only be found in the mixture of UltemR DAP/DODA system in p-chlorophenol, and this process does noteffectively occur in the UltemR DODA/DAP system in p-chlorophenol, indicating that free DODA canefficiently attack the imide linkage of UltemR DA-DAP. The final product resulting from the transimidizationin the mixtures is a random copolyimide with a major population of DAP as end groups for the copolymersystem. | Yoan Kim Doyun Kim Frank W.Harris Stephen Z.D.Cheng | 1999 | Chinese Journal of Polymer Science1999，17，2： | 0 |
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