Dai, Xuemin; Bao, Feng; Jiao, Long; Yao, Haibo; Ji, Xiangling; Qiu, Xuepeng; Men, Yongfeng
High-performance polyimide copolymer fibers derived from 5-anino-2-(2-hydroxy-4-aminobenzene)-benzoxazole: Preparation, structure and properties
A series of high-performance polyimide copolymer (co-PI) fibers containing phenylenebenzoxazole moiety with one hydroxyl group are synthesized based on the copolymerization of 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA) with two diamine monomers, namely, p-phenylenediamine (p-PDA) and 5-anino-2-(2-hydroxy-4-aminobenzene)-benzoxazole (p-mHBOA), through a two-step method. The molar ratio…
Hyperbranched poly(amido amine) demulsifiers with ethylenediamine/1,3-propanediamine as an initiator for oil-in-water emulsions with microdroplets
Zhang, Lifeng; Ying, Hao; Yan, Shu; Zhan, Ningning; Guo, Yongsheng; Fang, Wenjun
Two kinds of hyperbranched poly(amido amine) (h-PAMAM) with abundant terminal amine groups are synthesized to break the oil-in-water (O/W) emulsions consisting of microdroplets. The demulsification performance of h-PAMAM is systematically evaluated with assistance of UV–vis spectra, micrograph, DLS and SAXS analyses. The demulsifier with 1,3-propanediamine as initiator shows a striking…
Immobilization of the enzyme invertase in SBA-15 with surfaces functionalized by different organic compounds
Ribeiro, Livia M. O.; Falleiros, Larissa N. S. S.; de Resende, Miriam M.; Ribeiro, Eloízio J.; Almeida, Renata M. R. G.; da Silva, Antonio O. S.
The search for appropriate supports for enzyme immobilization has attracted increasing interest in the field of biocatalysis. Immobilized enzymes are catalysts of enormous industrial interest because they combine the advantages of heterogeneous catalysis with the high selectivity and mild operational conditions of enzymes. This study evaluated the use of different…
Influence of an external magnetic field in the two-photon absorption coefficient of magnetite nanoparticles in colloids and thin films
Espinosa, D. H. G.; Oliveira, C. L. P.; Neto, A. M. Figueiredo
The Z-scan nonlinear optical and the small-angle x-ray scattering (SAXS) techniques are used to investigate the structure and nonlinear optical properties of magnetite nanoparticles dispersed in a colloid and trapped in thin films. The nonlinear refractive index (n2) and the two-photon absorption coefficient (β) were measured as a function of…
Influence of Boron Nitride Nanosheets on the Crystallization and Polymorphism of Poly(l-lactide)
Rosely, C. V. Sijla; Nagendra, Baku; Sivaprasad, Vijayan Pillai; Gowd, E. Bhoje
This work reports on the impact of delaminated boron nitride nanosheets (BNNSs) on the crystallization behavior and crystalline structure of melt-crystallized poly-L-lactic acid (PLLA). Wide-angle X-ray diffraction and scanning electron microscopy data revealed that the addition of lower loadings of BNNSs (∼0.5 wt %) resulted in the highly dispersed PLLA…
Influence of different specific surface area of highly dispersible silica and interfacial characteristics of green elastomer composites
Manoharan, Partheban; Anagha, M. G.; Das, Narayan Chandra; Naskar, Kinsuk
Epoxidized natural rubber (ENR) is a modified form of NR bearing polar epoxy groups. The present study focuses on dispersion of highly dispersible silica (HDS) filler with three different specific surface areas in ENR 25/ENR 50 composites. The effect of three different specific surface areas of HDS on bound rubber…
Influence of fluorinated extractant aggregation in diluent on extraction of salicylic acid: Evidence from equilibrium, SAXS and molecular dynamics simulation
Wu, Xue; Chang, Zhidong; Feng, Jingge; Dang, Hui; Uslu, Hasan; Li, Wenjun
In order to get optimal extraction performance as well as ultra-low solvent residual, the extraction behavior of tris(2,2,3,3,4,4,4-heptafluorobutyl) phosphate (FTBP) dissolved in 2,3,4,5,6-Pentafluorotoluene (FB) was evaluated to investigate the influence of the aggregation state on the extraction of salicylic acid (SA). The effect of SA distribution and water content on…
Influence of processing conditions on mechanical properties of blends of styrenic block copolymer and poly(phenylene oxide): Miscibility and microdomain size
Yu, Xiangtian; Wang, Xiang; Zhang, Aiming; Zhou, Tao
The effect of processing conditions on mechanical properties of poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) and poly(2,6-dimethy-1,4-phenylene oxide) (PPO) blends were investigated. Differential scanning calorimetry and small angle X-ray scattering were used to study the miscibility and d-spacing of the blends. The processing temperature plays an important role in mechanical properties.…
Initial lamellar thickness dependency of recrystallization behavior of poly(4-methyl-1-pentene)
Chen, Ran; Lu, Ying; Jiang, Zhiyong; Men, Yongfeng
The isothermal crystallization and subsequent melting process in semicrystalline poly(4-methyl-1-pentene) were investigated via temperature-dependent small- and wide-angle X-ray scattering and Flash DSC techniques. In a phase diagram of inversed crystalline lamellar thickness and temperature, the crystallization and melting lines can be described by two linear dependencies of different slopes and…
Intrinsically disordered N-terminal domain of the Helicoverpa armigera Ultraspiracle stabilizes the dimeric form via a scorpion-like structure
Wycisk, Krzysztof; Tarczewska, Aneta; Kaus-Drobek, Magdalena; Dadlez, Michał; Hołubowicz, Rafał; Pietras, Zbigniew; Dziembowski, Andrzej; Taube, Michał; Kozak, Maciej; Orłowski, Marek; Ożyhar, Andrzej
Nuclear receptors (NRs) are a family of ligand-dependent transcription factors activated by lipophilic compounds. NRs share a common structure comprising three domains: a variable N-terminal domain (NTD), a highly conserved globular DNA-binding domain and a ligand-binding domain. There are numerous papers describing the molecular details of the latter two globular…