Synthesis and characterization of hybrid organic-inorganic materials based on EA-MAn-APTES and silica

Poly (EA-MAn-APTES)/silica hybrid materials were successfully prepared fromEthyl acrylate (EA), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of acoupling agent 3-aminopropyltriethoxysilane (APTES),by free-radical solution polymerization and insitu sol-gel process. The mass fraction of TEOS varied from 0 to 25%. The hybrid materials werecharacterized by the methods of FT-IR spectra, solvent extraction, scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC) andthermogravimetric analysis (TGA) measuring apparatus to get their structures, gel contents,morphologies, particle sizes and thermal performances. The results show that the covalent bonds arebetween organic and inorganic phases, gel contents in the hybrid materials are much higher, theSiO_2 phase is well dispersed in the polymer matrix, silicon dioxide exist at nanoscale in thecomposites and have excellent thermal stability.

The Evaluation of the Dietary Habits Influence on the Microhardness of Gingiva-Coloured Composite and Acrylic Denture Base Materials

Purpose: The study investigated the impact of dietary habits, specifically soda, milk kefir, water kefir, almond milk, and distilled water (control) consumption, on the microhardness of gingiva-coloured composite and acrylic denture bases. Methods: Materials included gingiva-coloured composite (Fusion Universal G1), acrylic (Imicryl), and subdivided Procryla group. Subgroups comprised 15 and 30-minute heat polymerized (Pro15, Pro30), and 1 wt% (Pro1Z) and 3 wt% (Pro3Z) zirconium added groups. Immersed in beverages for 1, 7, and 14 days, pH and microhardness were assessed. SEM examined random samples. Statistical analysis used repeated measures ANOVA, and post hoc tests (p Results: The gingiva-coloured composites displayed noteworthy time-associated microhardness changes (p 0.05). Despite variable pH levels in beverages, no substantial group interaction effects were observed (p > 0.05). Initial microhardness rankings shifted after a 14-day immersion. Conclusions: Gingiva-coloured composite exhibited the highest microhardness pre- and post-immersion, followed by Procryla30 and Imicryl groups. .

A Review on the Advancement of Renewable Natural Fiber Hybrid Composites: Prospects, Challenges, and Industrial Applications

Naturalfibre(NFR)reinforced functional polymer composites are quickly becoming an indispensable sustainable material in the transportation industry because of their lightweight,lower cost in manufacture,and adaptability to a wide variety of goods.However,the major difficulties of using thesefibres are their existing poor dimensional stability and the extreme hydrophilicity.In assessing the mechanical properties(MP)of composites,the interfacial bonding(IB)happening between the NFR and the polymer matrix(PM)plays an incredibly significant role.When compared to NFR/syntheticfibre hybrid composites,hybrid composites(HC)made up of two separate NFR are less prevalent;yet,these hybrid composites also have the potential to be valuable materials in terms of environmental issues.A new dimension to theflexibility of composites reinforced with NFR is added by the cost-effective manufacture of hybrid composites utilising NFR.The purpose of this study is to offer an over-view of the keyfindings that were presented on hybrid composites.The emphasis was focused on the factors that influence the performance of the naturalfiber composites,diverse approaches to enhancing MP,physical,electri-cal,and thermal characteristics of the HC.HC study in polymer science gains interest for applications in con-struction and automotive industries.

Flame Retardancy Enhancement of Hybrid Composite Material by Using Inorganic Retardants

This study aims to investigate the possibility of improving the flame Retardancy for the hybrid composite material consisting araldite resin (CY223). The hybrid composite was reinforced by hybrid fibers from carbon and Kevlar fibers on woven roving form (45o -0o), by using a surface layer of 4mm thick of Zinc Borate flame retardant. Afterward, the structure was exposed directly to gas flame of 2000oC due to 10 mm and 20mm exposure interval. The retardant layer thermal resistance and protection capability were determined. The study was continued to improve the performance of Zinc Borate layer mixed by 10%, 20% and 30% of Antimony Trioxide. To determine the heat transfer of the composite material the opposite surface temperature method was used. Zinc Borate with (30%) Antimony Trioxide gives the optimized result of the experiment.

Fabrication of branch-like Aph@LDH-MgO material through organic-inorganic hybrid conjugation for excellent anti-corrosion performance

Layered double hydroxides(LDH)frameworks have shown significant enhancement in stability and reusability,and their tailorable architecture brings new insight into the development of the next generation of hybrid materials,which attracted considerable attention in many fields over the years.One of the factors contributing to the widespread applicability of layered double hydroxides is their adaptable composition,which can accommodate a wide spectrum of potential anionic guests.This exceptional property makes the LDH system simple to adjust for various applications.However,most LDH systems are synthesized in situ in an autoclave at high temperatures and pressures that severely restrict the industrial use of such coating systems.In this study,LDH was directly synthesized on a magnesium alloy that had undergone plasma electrolytic oxidation(PEO)treatment in the presence of ethylenediaminetetraacetic acid,thereby avoiding the use of hydrothermal autoclave conditions.This LDH system was compared with a hybrid architecture consisting of organic-inorganic self-assembly.An organic layer was fabricated on top of the LDH film using 4-Aminophenol(Aph)compound,resulting in a smart hierarchical structure that can provide a robust Aph@LDH film with excellent anti-corrosion performance.At the molecular level,the conjugation characteristics and adsorption mechanism of Aph molecule were studied using two levels of theory as follows.First,Localized orbit locator(LOL)-πisosurface,electrostatic potential(ESP)distribution,and average local ionization energy(ALIE)on the molecular surface were used to highlight localization region,reveal the favorable electrophilic and nucleophilic attacks,and clearly explore the type of interactions that occurred around interesting regions.Second,first-principles based on density functional theory(DFT)was applied to study the hybrid mechanism of Aph on LDH system and elucidate their mutual interactions.The experimental and computational analyses suggest that the highπ-electron density and delocalization characteristics of the functional groups and benzene ring in the Aph molecule played a leading role in the synergistic effects arising from the combination of organic and inorganic coatings.This work provides a promising approach to design advanced hybrid materials with exceptional electrochemical performance.

Ablation Performance of a Novel Super-hybrid Composite

A novel super-hybrid composite (NSHC) was boron-modified phenolic resin (BPR) with three-dimensional reticulated SiC ceramic (3DRC) and high silica fibers. Ablation performance of the NSHC was studied. The results show that the linear ablation rate of NSHC was lower than that of pure BPR and the high silica/BPR composite. Its linear ablation rate is 1/17 of the high silica/BPR. Mass ablation rate of the NSHC is very close to that of the pure BPR and the high silica/BPR composite. Scanning electron microscope (SEM) analysis indicates that 3DRC has scarcely changed its shape at the ablation temperature. Its special reticulated structure can restrict the materials deformation and prevent high velocity heat flow from eroding the surface of the materials largely and thus increase ablation resistance of the NSHC.

Thermal Studies and Analytical Applications of a Newly Synthesized Composite Material “Polyaniline Stannic Molybdate”

Polyaniline stannic molybdate—an organic-inorganic composite material, was prepared via sol-gel mixing of organic polymer polyaniline into matrices of inorganic precipitate of stannicmolybdate. The composite material synthesized at pH 1.2 showed an ion exchange capacity 1.8 meq/g for Na+?ions. Ion exchange capacity, pH titration and distribution studies were carried out to determine the preliminary ion exchange properties of the material. The distribution studies showed the selectivity of Hg(II) ions by this material. The effect of temperature on the ion exchange capacity of the material at different temperatures had been studied. The sorption behavior of metal ions was also explored in different surfactant media.

Ablation Property of Ceramics/Carbon Fibers/Resin Novel Super-hybrid Composite

A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.

A Comparative Study on Several Anti-Corrosion Materials for Power FGD System

In the study organic-inorganic hybrid composite, epoxy modified silicone coating and vinyl ester flake mastic were comparatively used as several anti-corrosion materials that provided protection for flue gas desulfu-rization (FGD). The relationship between curing conversion rate of hybrid polymer and temperature was investigated by differential scanning calorimeter (DSC). The adhesion strength, coefficient of thermal expansion and flame retardant properties of three anti-corrosion materials were measured and analyzed. A corrosion test in 8% H2SO4 and 5% HCl at temperature cycle of 40°C~ 160°C was applied to study corrosion resistance of several anti-corrosion materials. Gravimetric measurement and morphological observation of three materials before and after corrosion test were comparatively analyzed in the paper. The small weight change and good morphological structure of hybrid composite during corrosion test demonstrate that hybrid composite has better anti-corrosion properties than epoxy modified silicone coating and vinyl ester flake mastic.

Regulatable Orthotropic 3D Hybrid Continuous Carbon Networks for Efficient Bi-Directional Thermal Conduction

Vertically oriented carbon structures constructed from low-dimen-sional carbon materials are ideal frameworks for high-performance thermal inter-face materials(TIMs).However,improving the interfacial heat-transfer efficiency of vertically oriented carbon structures is a challenging task.Herein,an orthotropic three-dimensional(3D)hybrid carbon network(VSCG)is fabricated by depositing vertically aligned carbon nanotubes(VACNTs)on the surface of a horizontally oriented graphene film(HOGF).The interfacial interaction between the VACNTs and HOGF is then optimized through an annealing strategy.After regulating the orientation structure of the VACNTs and filling the VSCG with polydimethylsi-loxane(PDMS),VSCG/PDMS composites with excellent 3D thermal conductive properties are obtained.The highest in-plane and through-plane thermal conduc-tivities of the composites are 113.61 and 24.37 W m^(-1)K^(-1),respectively.The high contact area of HOGF and good compressibility of VACNTs imbue the VSCG/PDMS composite with low thermal resistance.In addition,the interfacial heat-transfer efficiency of VSCG/PDMS composite in the TIM performance was improved by 71.3%compared to that of a state-of-the-art thermal pad.This new structural design can potentially realize high-performance TIMs that meet the need for high thermal conductivity and low contact thermal resistance in interfacial heat-transfer processes.

Dimensioning of Punctiform Metal-Composite Joints: A Section-Force Related Failure Criterion

Reliable line production processes and simulation tools play a central role for the structural integration of thermoplastic composites in advanced lightweight constructions. Provided that material-adapted joining technologies are available, they can be applied in heavy-duty multi-material designs (MMD). A load-adapted approach was implemented into the new fully automatic and fault-tolerant thermo mechanical flow drill joining (FDJ) concept. With this method it is possible to manufacture reproducible high strength FRP/metal-joints within short cycle times and without use of extra joining elements for the first time. The analysis of FDJ joints requires a simplified model of the joint to enable efficient numerical simulations. The present work introduces a strategy in modeling a finite-element based analogous-approach for FDJ-joints with glass fiber reinforced polypropylene and high-strength steel. Combined with a newly developed section-force related failure criterion, it is possible to predict the fundamental failure behavior in multi-axial stress states. The functionality of the holistic approach is illustrated by a demonstrator that represents a part of a car body-in-white structure. The comparison of simulated and experimentally determined failure loads proves the applicability for several combined load cases.

Enhancement of superconductivity in organic-inorganic hybrid topological materials

Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity.Reducing the thickness of transition metal dichalcogenides(e.g.WTe2 and MoTe2)has provided an important pathway to engineer superconductivity in topological matters.However,such monolayer sample is difficult to obtain,unstable in air,and with extremely low Tc.Here we report an experimentally convenient approach to control the interlayer coupling to achieve tailored topological properties,enhanced superconductivity and good sample stability through organic-cation intercalation of the Weyl semimetals MoTe2 and WTe2.The as-formed organic-inorganic hybrid crystals are weak topological insulators with enhanced Tc of 7.0 K for intercalated MoTe2(0.25 K for pristine crystal)and2.3 K for intercalated WTe2(2.8 times compared to monolayer WTe2).Such organic-cation intercalation method can be readily applied to many other layered crystals,providing a new pathway for manipulating their electronic,topological and superconducting properties.

Organic-inorganic Hybrid Materials Based on Molybdophosphate and Organic Polyammonium

A new organic-inorganic hybrid compound （dienHs）2（P2Mo5O23） （1） [dien=NH（CH2CH2NH2）2] has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, thermogravimetric analysis, and the single crystal X-ray diffraction technique. Compound 1 crystallizes in the triclinic system with space group P1 and a=0.9790（2） nm, b=0.9922（2） nm, c= 1.4644（3） nm, α=95.510（10）°, β=98.860（10）°, γ=95.700（10）°, V=1.3895（5） nm^3, Z=2, R=0.0465. The results show that the compound consists of dienH3^3＋＋ and P2Mo5O23^6-, and the heteropoly anion P2Mo5O23^6- is connected to a 1-D chain structure with the protonated dien by hydrogen bonds.

Functional-template directed self-assembly(FTDSA) of mesostructured organic-inorganic hybrid materials

Since the discovery of a surfactant directed self-assembly approach for the fabrication of mesoporous silica in 1992,increasing attention has been focused on the design and synthesis of mesostructured functional materials.Organic functionalization is becoming a major topic in this research field,since highly ordered mesostructured organic-inorganic hybrids offer novel functionalities and enhanced performance over their individual components.We begin with a brief overview of the three fundamental methods(post-synthetic grafting technique,co-condensation method,and preparation of periodic mesoporous organosilicas) for the preparation of organically functionalized mesostructured silica,and focus on one of the most promising approaches,which herein was named as functional-template directed self-assembly(FTDSA) approach,and in the eyes of the authors it has a special position in the preparation of this class of hybrid materials.A comprehensive overview of the state of research in the area of FTDSA and its potential applications will be given.

Fabrication of 2×2 Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by Sol-Gel Technique

2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms and switching power 9.3 mW.

Enhanced photocatalytic hydrogen production under visible light of an organic-inorganic hybrid material based on enzo[1,2-b:4,5-b']dithiophene polymer and TiO_(2)

Titanium dioxide(TiO_(2))has been limited in photocatalysis due to its wide band gap(3.2 eV)and limited absorption in the ultraviolet range.Therefore,organic components have been introduced to hybrid with TiO_(2) for enhanced photocatalytic efficiency under visible light.Here,we report that benzo[1,2-b:4,5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO_(2).The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0μmol g^(-1) h^(-1) under visible light irradiation.Meanwhile,the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles.The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions.Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.

双种群混合遗传算法求解航空复合材料柔性调度问题

考虑航空复合材料柔性车间调度中的运输约束,以最小化完工时间为目标,建立调度模型,提出一种改进的双种群混合遗传算法进行求解。根据问题特点,基于工序排序、机器选择和运输约束3个子问题,设计三层实数编码以及对应解码方案。采用混合初始化提高种群质量,进化过程中采用交叉算子执行全局搜索,为双种群设计基于机器负载平衡和变邻域的局部搜索,提高全局和局部搜索能力。与对比算法相比10个测试算例中BPRD指标取得9个最优,APRD指标全部取得最优,t检验显著性有明显差异,验证算法的优越性。将算法应用于航空复合材料车间中,实现实际生产的调度,验证算法的可行性。

大展弦比混杂纤维复合材料机翼的强度及失效分析

以大展弦比机翼为研究对象,基于经典层合板理论和Tsai-Wu失效准则,考虑几何非线性效应,用流固耦合数值模拟方法,重点研究碳/玻纤维混杂比、铺层相对位置、铺层角度对机翼强度及失效特性的影响。研究表明:碳/玻纤维混杂比=8∶2为最佳纤维混杂比,机翼可兼顾高强度、低成本;玻璃纤维铺设在蒙皮对称中面位置时,机翼的强度及安全性更高,玻璃纤维铺设位置的变化不会对机翼的弹性变形产生显著影响;在不同混杂比下,以±45°铺层角度铺设的机翼整体力学性能更稳定,失效概率更低。

不同温度环境下复合材料/金属混合壁板结构热应力试验研究

极端气候条件,如高温、低温和湿热环境,均会影响飞机上复合材料/金属混合结构的承载能力和工作寿命,进而影响飞机的飞行性能和安全。由于复合材料和金属材料之间的热膨胀系数差异较大,实际飞行中遇到的温度变化会导致复合材料元件和金属元件内部产生较高的热应力。这种附加热应力会改变复合材料/金属混合连接结构内部的载荷传递和内应力分布情况。对大规模、多钉连接的复合材料/金属混合结构壁板在不同温度环境中的热力学行为进行了试验研究,并研究了不同温度条件下受到单向拉伸载荷时的热力响应。通过试验过程中的应变变化,对不同环境和载荷条件下复合材料/金属混合结构内不同组件的应力分布和钉载情况进行了分析。