Thermoreversible Thickening and Self-assembly Behaviors of pH/Temperature Dually Responsive Microgels with Interpenetrating Polymer Network Structure

The pH /temperature dually responsive microgels of interpenetrating polymer network( IPN) structure composed of poly( N-isopropylacrylamide)( PNIPAM) network and poly( acrylic acid)( PAA) network( PNIPAM /PAA IPN microgels) were synthesized by seed emulsion polymerization. The results obtained by dynamic laser light scattering( DLLS) show that the microgels have good pH /temperature dual sensitivities. The temperature sensitive component and the pH sensitive component inside the microgels have little interference with each other. The rheological properties of the concentrated PNIPAM /PAA IPN microgel dispersions as a function of temperature at pH 4. 0 or 7. 0 were investigated by viscometer,and the results displayed that only at pH 7. 0 the dispersions presented thermoreversible thickening behavior. Then the PNIPAM /PAA fibers were prepared by self-assembly of the PNIPAM /PAA IPN microgels in the ice-crystal templates formed by unidirectional liquid nitrogen freezing method. Field emission scanning electron microscopy( FESEM) images indicate that the PNIPAM /PAA fibers are rounded,randomly orientated and interweaved.

Synthesis and Crystal Structure of a Three-dimensional (3D) Complex Mn(H_2O)_2(HNic)_2 (HNic=2-Hydroxynicotinic Acid)

The title complex Mn（H2O）2（HNic）2 （C22H12MnN2O8, Mr = 367.18） crystallizes in monoclinic, space group P21/c with a = 7.5735（8）, b = 12.5295（13）, c = 7.6466（8）A.β = 101.2790（10）°, Z = 2, V= 711.59（13） A^3, D, = 1.714 g/cm^3,μ（MoKa） = 0.974 mm^-1, F（000） = 374, R1 （1255 observed reflections （Ⅰ 〉 2σ（Ⅰ）） = 0.0250） and wR2 = 0.0662 （all data）. In this paper, we report the complexation of Mn（Ⅱ） by the bidentate ligand 2-hydroxynicotinic acid （HNic）. In the crystal the Mn（Ⅱ） ion exhibits a deformed octahedron structure. The title complex Mn（H2O）2（HNic）2 has a three-dimensional （3D） network structure extended by hydrogen bonds, which are formed by two typical eight-membered hydrogen-bonded rings.

Three-dimensionally interconnected Co9S8/MWCNTs composite cathode host for lithium–sulfur batteries

Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur batteries.In this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur host.The assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 C.The polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling effect.Meanwhile,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li ions.Polysulfide adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.

Preparation and Crystal Structure of Sarcosine 5-Nitrosalicylic Acid Organic Adduct

The title compound (C10H12N2O7, Mr = 272.22) crystallizes in triclinic, space group P1 with a = 5.532(2), b = 9.760(4), c = 11.731(5) ?, α = 68.107(7), β = 89.179(7), γ = 77.830(7)o, V = 573.1(4) ?3, Z = 2, Dc = 1.578 g/cm3, F(000) = 284 and μ(MoKa) = 0.136 mm-1. The final R = 0.0400 and wR = 0.0951 for 1468 observed reflections with I > 2σ(I). The title compound is a 1:1 adduct of sarcosine and 5-nitrosalicylic acid. The nitrogen atom of sarcosine is protonated, and the proton is from the carboxyl group of sarcosine and 5-nitrosalicylic acid with the probability of 50 percent for each. The 5-nitrosalicylic acid and sarcosine molecule of the title adduct are ABAB arranged along the c axis. There exist a lot of hydrogen bonds in the structure, linking sarcosine and 5-nitrosalicylic acid to form a three-dimensional network.

Hydrothermal Synthesis and Crystal Structure of a New Sandwich-type Molybdenum Phosphate

The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.

Synthesis and Crystal Structure of O-Ethyl-N- (2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate

The crystal and molecular structures of O-ethyl-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography. It crystallizes in the orthorhombic system with space group P2(1)2(1)2(1), lattice parameters a=0.90636(18) nm, b=0.94716(19) nm, c=2.1855(4) nm, V=1.8762(7) nm 3, and Z=4. All the substituents are in equatorial positions. There are four intramolecular interactions, each forming a five-membered ring. The molecules are linked by interactions to form three-dimensional framework. Atoms O6 and O8 show positional disorder.

AlSi11/ Si₃N₄Interpenetrating Composites Tribology Properties of Aluminum Matris Composites

In present work, the metal-ceramic interpenetrating composites (IPCs) as AlSi11/ Si3N4 are fabricated by infiltrating technique. IPCs exhibit special characterization of brittle ceramic reinforced phase introduced by ductile metal matrix phase. During the sliding wear processes, IPCs exhibit four wear mechanism such as initial adhesive wear, mixed adhesive and abrasive wear, adhesive wear and final abrasive wear. Reinforcements inhibit plastic flow and restrict propagation of wear cracks. Increase in the volume fraction of reinforcement leads to improvement in the wear resistance. Under higher load and lower round speed conditions, the friction coefficients are lower than that of relative conditions.

ClO_4^--directed Assembly of Two Co^ⅡComplexes Based on Flexible N-donor Ligands:Syntheses,Crystal Structures and Magnetic Properties

The reaction of Co^II ions with 1,4-bis（imidazol）butane（bimb） or 1,4-bis（triazol）butane（bitb） in the presence of ClO4^-, respectively affords two CoII coordination complexes, namely {[Co（bimb）3]·2ClO4}n（I） and {[Co（bitb）3]·2ClO4}n（II）. Single-crystal X-ray analysis indicates that both complexes I and II show the same α-Po topological structures. However, complex I exhibits a 2-fold interpenetrating network, while complex II features a 3-fold interpenetrating network. In addition, solid-state properties such as thermal stabilities and magnetic properties of two complexes were also investigated.

Generative deep-learning-embedded asynchronous structured light for three-dimensional imaging

Three-dimensional(3D)imaging with structured light is crucial in diverse scenarios,ranging from intelligent manufacturing and medicine to entertainment.However,current structured light methods rely on projector-camera synchronization,limiting the use of affordable imaging devices and their consumer applications.In this work,we introduce an asynchronous structured light imaging approach based on generative deep neural networks to relax the synchronization constraint,accomplishing the challenges of fringe pattern aliasing,without relying on any a priori constraint of the projection system.To overcome this need,we propose a generative deep neural network with U-Net-like encoder-decoder architecture to learn the underlying fringe features directly by exploring the intrinsic prior principles in the fringe pattern aliasing.We train within an adversarial learning framework and supervise the network training via a statisticsinformed loss function.We demonstrate that by evaluating the performance on fields of intensity,phase,and 3D reconstruction.It is shown that the trained network can separate aliased fringe patterns for producing comparable results with the synchronous one:the absolute error is no greater than 8μm,and the standard deviation does not exceed 3μm.Evaluation results on multiple objects and pattern types show it could be generalized for any asynchronous structured light scene.

The three-dimensional structure and the relationship between external and internal vascularizations in the brain of rat embryos

Background There have been no detailed reports of the three-dimensional structure and the relationship between the external and internal vascularizations observed successively for a long duration in the rat fetus, although many authors have studied the vascular morphology of the developing brain. This study examined the three-dimensional structure of both the external and internal vascularizations of the prenatal rat telencephalon from embryonic days 12 (E12) to 20 (E20).Method A microvascular casting method for scanning electron microscopy (SEM) was used in this study, along with vascular staining using gold-gelatine solution-autometallography (GGS-AMG) after intravascular injection of colloidal gold, as well as hematoxylin-eosin ( HE) staining for paraffin embedded specimens.Results In GGS-AMG stains, E16 fetuses had a few short perforating cortical blood vessels (SPCVs); E17 fetuses had long perforating cortico-medullary vessels (LPCVs). Older fetuses had specific patterns of vascular networks in the cortex and the deeper subcortical part of the telencephalon. In the cortex, fine longitudinal blood vessels were connected by transverse channels. The deep telencephalon had fine blood vessels running in all directions. Using SEM, the external vascularization was already visible in E12 fetuses as arborizations of arterial branches, forming a mesh of fine vascular networks covering the telencephalon. A coralliform fine venous plexus was observed in the external vascularization of E16 fetuses. There were ring-like anastomoses and bud-like protrusions in the network of small blood vessels, most likely the angiogenesis of fetal vessels. From E12 to E16, an immature and incomplete internal vascularization began to appear. There were short blood vessels with ballooned terminals branching from the external vascularization. They penetrated the brain tissue to form networks in the superficial layer, comparable to SPCVs. In E17 to E20 fetuses, tortuous venous branches, straight arterial blood vessels, and a fine network of small blood vessels formed the external vascularization. There were fewer arterial than venous branches connecting to the fine networks of small blood vessels. LPCVs were noted at E17, at the time the white matter emerged. They branched from the external vascularization, and perpendicularly penetrated the brain surface, traversing the cortical plate, and entering into the deep brain. At E17, arterial and venous blood vessels could be clearly distinguished in the external vascularization. At E20, the cortex and white matter contained specific arrangements of networks of fine blood vessels, as seen by GGS-AMG staining.Conclusion These findings show that the development of both the external and internalvascularization follows the development of thetelencephalon. In particular, the emergence ofthe cortical plate and white matter on E16 andE17 influence the development of both theinternal and the external vascularization. Thelaminal arrangement of blood vessels was notobserved corresponding to the respective laminalneuronal layers.

互穿网络结构的二氧化硅/环氧树脂复合材料的制备及介电性能研究

环氧树脂(EP)具有较高的电绝缘性能和较低的介电损耗,因此被广泛应用于电气设备和电子封装等绝缘材料领域。由于传统EP耐热性能较差、韧性不足,极大限制了其作为微电子元器件在高频电场下的使用。本工作以硅烷偶联剂(3-环氧乙基甲氧基丙基)三甲氧基硅烷(KH-560)和正硅酸乙酯(TEOS)为原料,通过溶胶-凝胶法合成末端含有环氧基团的新型端环氧基纳米SiO_(2)(E-SiO_(2)),用其对E-51型EP进行改性,在固化剂作用下使E-SiO_(2)和EP上的环氧基团发生开环反应,通过有机EP与无机E-SiO_(2)填料之间的化学键结合,制备出具有互穿网络结构的E-SiO_(2)/EP复合材料。本工作研究了添加E-SiO_(2)对EP固化反应工艺和综合性能的影响,以期在保证EP低介电常数和低介电损耗的同时,赋予其良好的韧性和耐热性能,为EP在高频电路下的应用奠定基础。

耐高温湿法缠绕树脂的制备及其应用

目前,普遍使用的湿法缠绕树脂的耐高温性能不足,制备的碳纤维复合材料难以满足新一代武器装备对性能的需求。通过采用多官能度芳香族环氧树脂作为基体,添加环氧基多面体聚倍半硅氧烷(EPOSS)形成有机-无机杂化网络结构,实现了在保证固体火箭发动机碳纤维缠绕壳体工艺性的同时,还显著提高了湿法缠绕树脂的玻璃化转变温度,具备较高的应用价值。结果表明:在EPOSS添加量为环氧组分的7.5%时湿法缠绕树脂具备最高的耐热性,其玻璃化转变温度高达230℃,能够满足某型号固体火箭发动机壳体的性能需求。

Reproducible and low-power multistate bio-memristor from interpenetrating network electrolyte design

Bio-memristor can address the inherent limitations of conventional memory components in artificial perceptual systems due to their biocompatibility with biological tissue.The actual deployment of bio-memristor is restricted by the lack of reproducibility,high power consumption,and insufficient storage capacity.Here,a reproducible and low-power multistate biomemristor is developed by designing the chitosan(CS)-reduced graphene oxide(rGO)interpenetrating network electrolyte.The interpenetrating network structure of the CS-rGO electrolyte reinforces structural stability and improves ionic conductivity.The bio-memristor equipped with CS-rGO active layer shows stable bipolar resistive switching up to 100 consecutive cycles,reproducible multistate storage with six different memory states,and low programming power of 9.4μW.The fabricated biocompatible CS-rGO device also exhibits deformation stability of memory operation over 103 bending cycles,high biocompatibility with HEK293 cells,and skin adhesion.This work provides an enlightening design strategy to develop highperformance bio-memristors for applications in artificial perceptual systems.

聚醚型聚氨酯/乙烯基酯树脂互穿聚合物网络结构的研究

以聚氨酯（ＰＵ）为组分Ⅰ、乙烯基酯树脂（ＶＥＲ）为组分Ⅱ，采用二步法制备了聚氨酯／乙烯基酯树脂互穿聚合物网络（ＰＵ／ＶＥＲ－ＩＰＮ），采用透射电镜（ＴＥＭ）和原子力显微镜观察了ＰＵ／ＶＥＲ－ＩＰＮ的微观形态，用调制ＤＳＣ（Ｍ－ＤＳＣＴＭ ）、动态力学分析方法（ＤＭＡ）研究了ＩＰＮ 的玻璃化转变行为及动态力学性能。结果表明，ＰＵ 网络与ＶＥＲ网络形成了多相微区结构，在界面处互穿和缠结，形成类似胞状的结构，ＰＵ 相为胞壁，ＶＥＲ为胞体。在ＰＵ 和ＶＥＲ之间，次级作用明显加强，出现氢键吸收峰，并且出现宽温度阻尼范围。当ＰＵ／ＶＥＲ＝ ４０／６０ 时。

MDI聚氨酯/聚硅氧烷IPN的结构与力学性能

用MDI聚醚氨酯和含少量苯基的聚二甲基硅氧烷合成了一系列的聚氨酯/聚硅氧烷IPN阻尼弹性体,研究了材料的结构与力学性能。结果表明,当聚氨酯与聚硅氧烷的质量比为90:10时,IPN的抗张强度达41.57MPa,断裂伸长率为376％,并具有良好的阻尼性能,玻璃化转变温度范围大于80℃。聚氨酯/聚硅氧烷IPN具有细微的微相分离结构,聚硅氧烷在IPN中的微相尺寸为微米级,并趋向于分布在IPN的表面。

聚氨酯改性TDE-85/MeTHPA环氧树脂体系的结构表征

选用聚醚二元醇(PPG)和甲苯二异氰酸酯(TDI)为原料,合成聚醚型聚氨酯预聚体。采用该聚氨酯预聚体(PUP)、扩链剂、交联剂对TDE-85/甲基四氢邻苯二甲酸酐(MeTHPA)环氧树脂进行改性,通过扫描电镜与红外光谱分析,探讨聚氨酯(PU)改性环氧树脂(EP)体系的结构特征。结果表明:TDE-85与MeTHPA之间发生固化反应,形成环氧聚合物网络Ⅰ;1,4-丁二醇(1,4-BDO)及三羟甲基丙烷(TMP)与PU预聚体之间发生了扩链、交联反应,形成聚氨酯聚合物Ⅱ;PU改性TDE-85/MeTHPA树脂为非均相结构,PU含量是影响PU/EP材料两相相容性和相区尺寸的主要因素;当添加的PUP质量分数为15%时,PU改性TDE-85/MeTHPA体系具有互穿聚合物网络结构特征。

聚氨酯乳液互穿聚合物网络的制备与结构

以甲苯二异氰酸酯(TDI)、聚己二酸丁二醇酯(PBA2000)和环氧树脂(E-20)为主要原料,制备了高环氧树脂含量的聚氨酯(PU)/环氧树脂(EP)乳液互穿聚合物网络(LIPN)。通过红外光谱,动态力学分析,透射电镜等研究了产物的结构与性能。结果表明,LIPN已形成,乳液乳胶粒子为非核壳结构,EP和PU两种组分完全互容且在分子尺度互穿。改性PU的耐溶剂性大幅提高,表现出明显的互穿协同效应。可作为一种新型的环保PU涂层应用于各个领域。

聚氨酯/聚甲基丙烯酸甲酯/有机蒙脱土纳米复合材料的结构、形态与力学性能

将插层纳米复合技术与同步互穿聚合物网络(IPN)技术相结合,制备了聚氨酯(PU)/聚甲基丙烯酸甲酯(PMMA)/有机蒙脱土(OMMT)纳米复合材料.用XRD,SEM,TEM等手段并通过力学性能测试研究了该复合材料和相应的PU/PMMA-IPN材料的结构、形态和力学性能.结果表明,PU/PMMA/OMMT纳米复合材料中一部分蒙脱土以8～20nm厚、50～200nm长的片层有序地分布在聚合物基体中,形成了插层/剥离型纳米复合材料,其力学性能显著优于相应的PU/PMMA-IPN材料.OMMT易与PU/PMMA/OM-MT体系中的PU硬段及PMMA分子链形成氢键结合,使得OMMT,PU,PMMA彼此之间的相互作用加强,相容性改善,导致体系的力学性能显著提高.文中还研究了OMMA添加量、PU/PMMA质量比、过氧化二苯甲酰(BPO)添加量、二甲基丙烯酸乙二酯(EGDMA)添加量、1,4丁二醇(BDO)系数等因素对PU/PMMA/OMMT纳米复合材料力学性能的影响,获得PU/PMMA/OMMT纳米复合材料的最佳制备条件为:PU/PMMA质量比为60/40,OMMT,BPO和EGDMA添加量分别为MMA单体质量的5.0%,0.80%和2.0%,BDO系数为0.80.

透明屏蔽材料的研究现状及展望

阐述了研究透明屏蔽材料在军用和民用事业上的重要意义。在分析屏蔽材料作用机理的基础上,提出屏蔽材料能够透光对导电粒子的要求,同时介绍当前透明屏蔽材料的两个热点研究方向,对薄膜型透明屏蔽材料和互穿网络结构型透明屏蔽材料的研究现状做了详细的叙述。在总结上述两种材料各自特点的基础上,提出具有一定厚度的均匀复合体材料才是将来最理想的透明屏蔽材料,并对透明屏蔽体材料的研究和发展趋势作了简要的阐述和展望。

胶乳型互穿聚合物网络研究 Ⅲ.环氧树脂/聚丙烯酸酯Semi-LIPN的结构与性能

通过ＩＲ、ＤＳＣ、ＴＧ、ＴＥＭ、溶胀比测定等方法，对丙烯酸丁酯－苯乙烯－甲基丙烯酸甲酯（ＢＡ－Ｓｔ－ＭＭＡ）交联共聚物的结构和ＥＰ／Ｐ（ＢＡ－Ｓｔ－ＭＭＡ）Ｓｅｍｉ－ＬＩＰＮ（ＥＰ为环氧树脂）的结构、热稳定性、溶胀性及乳胶膜的吸水性、乳胶粒形态进行了研究。结果表明，ＢＡ－Ｓｔ－ＭＭＡ共聚物中主要是无规共聚物，也含有嵌段或接枝共聚的链段，但并不太长；当该Ｓｅｍｉ－ＬＩＰＮ受热时，其中的ＥＰ因未交联而先行分解；ＥＰ的加入使乳胶膜的吸水性降低；在乳胶粒的测试过程中，由于分散程度不同还观察到了网络结构。