Polybenzoxazine/organosilicon composites with low dielectric constant and dielectric loss

The evolution of electronic communication technology raises higher requirements for low dielectric constant(low-k)materials.For this,a benzoxazine functional organosilicon(HP-aptes)with dense Si—O—Si crosslinking networks and large sterically hindered tert-butyl groups was prepared by the sol–gel method.Then,a series of polybenzoxazine composites(PPHP)were prepared from intrinsically low dielectric constant bis-functional benzoxazine monomer(P-aptmds)and HP-aptes.The double crosslinking networks of polybenzoxazine and organosilicon further increased the crosslinking density and decreased the dipole density of composites,which endowed the composites with enhanced low-k properties.When the content of HP-aptes is 30%(mass),the crosslinking density was 2.05×10^(-3)mol·cm^(-3),while that of PP-aptmds was 3.31×10^(-3)mol·cm^(-3).In addition,the dielectric constant and dielectric loss of PPHP composite at 1 MHz could reach 2.61 and 0.0056,respectively.

Functionalization of Silica Surface with UV-Active Molecules by Multivalent Organosilicon Spacer

Immobilization of active molecules by attachment onto solid surfaces is a well-established practice in many processes and applications. Silica micro- and nano-particles are attractive candidates as support for active molecules as a result of a combination of desirable properties. The present study deals with grafting of a functional UV active molecule onto silica surfaces via hydrosilylation reactions using multivalent organosilicon spacers. Different types of organosilicon precursors based on dimethylsiloxysilanes containing multiple SiH groups were used as spacers between vinyl-modified silica surface and the benzotriazole UV-absorber (UVA). Firstly, the surface of silica was modified with vinyltrimetoxsisilane coupling agent. The UVA molecules were attached to the silica-vinyl by a two-step procedure involving hydrosilylation reaction. The successful grafting was confirmed by FTIR, TGA and UV-Vis characterization. More than fivefold increase in UVA loading was found for the MH30 multifunctional spacer, which contains approximately 75 SiH groups per molecule, when compared to a four-functional spacer. Furthermore a branched, bulky six-functional spacer is preferred over a linear spacer of the same functionality. UV activity of functionalized silica was studied by UV-Vis spectroscopy, indicating that the immobilization of UVA onto silica surface has not altered its UV absorbance properties.

Deposition of organosilicone thin film from hexamethyldisiloxane(HMDSO)with 50kHz/33MHz dual-frequency atmospheric-pressure plasma jet

The deposition of organosilicone thin films from hexamethyldisiloxane(HMDSO) by using a dual-frequency(50 kHz/33 MHz) atmospheric-pressure micro-plasma jet with an admixture of a small volume of HMDSO and Ar was investigated.The topography was measured by using scanning electron microscopy.The chemical bond and composition of these films were analyzed by Fourier transform infrared spectroscopy(FTIR) and x-ray photoelectron spectroscopy.The results indicated that the as-deposited film was constituted by silicon,carbon,and oxygen elements,and FTIR suggested the films are organosilicon with the organic component(-CH_x)and hydroxyl functional group(-OH) connected to the Si-O-Si backbone.Thin-film hardness was recorded by an MH-5-VM Digital Micro-Hardness Tester.Radio frequency power had a strong impact on film hardness and the hardness increased with increasing power.

Synergistic Activity of Organosilicone to Emamectin Benzoate against Beet Armyworm (Spodoptera exigua Hübner)

Based on determination for surface tension of organosilicone solution and its expansion on the solid surface,the biological activity of 5% emamectin benzoate WDG with organosilicone against beet armyworm was determined by spraying method to study their synergistic activity. The results showed that organosilicone significantly reduced surface tension of aqueous solution,and the surface tension was reduced to 26mN/m as the concentration of organosilicone was 0.01%. The organosilicone significantly raised expansion of liquid drops on solid surface,and the expansion diameter of 10 μL 0.01% organosilicone was 34 mm. The indoor toxicity results indicated that when addition dosage of organosilicone was 1%-5%,synergistic activity of 5% emamectin benzoate WDG with organosilicone against beet armyworm was significant,and increase extent of synergistic activity slowed down as organosilicone dosage was higher than 5%. Field experiment showed that the control efficacies of 5% emamectin benzoate WDG + 5% organosilicone 33 mg/L against beet armyworm were 81.57% and 82.66% after spraying for 3 and7 d respectively,which were significantly better than treatments of 5% emamectin benzoate WDG 33 mg/L,24% metaflumizone SC 96 mg/L,5% chlorantraniliprole SC 33 mg/L,20% flubendiamide WDG 40 mg/L and 15% indoxacarb EC 43 mg/L.

A novel nano-grade organosilicon polymer:Improving airtightness of compressed air energy storage in hard rock formations

Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.

Recent Advance in Low-Dielectric-Constant Organosilicon Polymers

Comprehensive Summary,Low dielectric(low-k)organosilicon polymers have received extensive interests from industry and academia due to good electrical insulation,high temperature resistance,flame retardancy and hydrophobicity.These attractive properties enable them to be utilized as low-k materials in fabrication of electronic devices in high-frequency communication technology.This review summarizes recent progress in developing low-k organosilicon polymers,including the synthetic methods and properties of different organosilicon polymers classified according to the chemical structures.It may provide some inspiration to design new low-k organosilicon polymers for application in the.

页岩气调查井复杂地层有机硅聚合物钻井液体系的研制与应用

页岩气调查井通常地质条件复杂,钻探难度大。在对页岩气调查川沐地2井井壁稳定性分析的基础上,优选了有机硅聚合物钻井液体系,并通过正交试验,明确了有机硅改性聚合物、多级配超细碳酸钙、乳化石蜡和硅氟聚合物等主要处理剂的最优加量,形成了基本配方,在室内实验评价中该体系展现了良好的抗钻屑污染能力、抗钙侵能力、抑制性和封堵性。现场应用表明,川沐地2井在采用有机硅聚合物钻井液体系后,井内复杂情况得到明显改善,有效保障了井内安全,并顺利钻进至设计井深,实现了地质目标,钻进效率相比同区域同类型钻井大幅提高。研究成果可为页岩气调查井复杂地层钻探钻井液的选择与应用提供借鉴。

改性硅溶胶封孔剂对多孔Al_(2)O_(3)陶瓷绝缘性能和微观结构的影响

采用甲基三甲氧基硅烷和二甲基二甲氧基硅烷对硅溶胶进行改性制得有机硅改性硅溶胶封孔剂,并通过浸渍和加热固化的方法对多孔Al_(2)O_(3)陶瓷片进行封孔处理。研究了固化温度和固化时间对封孔Al_(2)O_(3)陶瓷片绝缘性能的影响,并对多孔Al_(2)O_(3)陶瓷片封孔前后的微观结构进行了表征。结果表明,较佳封孔条件为固化温度120℃、固化时间60 min,此时封孔Al_(2)O_(3)陶瓷片的直流和交流击穿电压分别达到最大值10.76 kV和6.01 kV,1000 V绝缘电阻不低于9999 MΩ。封孔Al_(2)O_(3)陶瓷片表面为改性硅溶胶涂层,呈致密无孔隙状态且与基体结合紧密,涂层厚度约为25μm,表面水接触角提高到86.93°,封孔层深度约为10μm。

Optimal synthesis of heat-integrated distillation configurations using the two-column superstructure

In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocolumn configuration.However,this approach frequently necessitates tedious enumeration procedures,resulting in a considerable computational burden.To surmount this formidable challenge,the present study introduces an innovative remedy:The proposition of a superstructure that encompasses both single-column and multiple two-column configurations.Additionally,a simultaneous optimization algorithm is applied to optimize both the process parameters and heat integration structures of the twocolumn configurations.The effectiveness of this approach is demonstrated through a case study focusing on industrial organosilicon separation.The results underscore that the superstructure methodology not only substantially mitigates computational time compared to exhaustive enumeration but also furnishes solutions that exhibit comparable performance.

Organosilicon polymer-derived ceramics: An overview

Polymer-derived ceramics(PDCs) strategy shows a great deal of advantages for the fabrication of advanced ceramics. Organosilicon polymers facilitate the shaping process and different silicon-based ceramics with controllable components can be fabricated by modifying organosilicon polymers or adding fillers. It is worth noting that silicate ceramics can also be fabricated from organosilicon polymers by the introduction of active fillers, which could react with the produced silica during pyrolysis. The organosilicon polymer-derived ceramics show many unique properties, which have attracted many attentions in various fields. This review summarizes the typical organosilicon polymers and the processing of organosilicon polymers to fabricate silicon-based ceramics, especially highlights the three-dimensional(3 D) printing technique for shaping the organosilicon polymerderived ceramics, which makes the possibility to fabricate silicon-based ceramics with complex structure. More importantly, the recent studies on fabricating typical non-oxide and silicate ceramics derived from organosilicon polymers and their biomedical applications are highlighted.

有机硅基RAFT试剂制备聚醚改性有机硅消泡剂

以八甲基环四硅氧烷和巯丙基甲基二甲氧基硅烷为原料,合成了巯基硅油;再以巯基硅油、CS_(2)和2-溴代异丁酸甲酯为原料,合成了有机硅基可逆加成-断裂链转移(RAFT)试剂(RAFT-SSO);RAFT-SSO与甲基封端的烯丙基聚氧乙烯醚(EO)、甲基封端的烯丙基聚氧丙烯醚(PO)采用RAFT聚合反应合成了聚醚改性有机硅消泡剂(RS-EOPO)。采用FTIR、1HNMR,GPC对RS-EOPO进行了结构表征,对其消泡、抑泡、相容性进行了测试,并将RS-EOPO与进口消泡剂性能进行对比。RS-EOPO最佳合成工艺条件为RAFT-SSO相对分子质量为2000、m(EO)∶m(PO)=1∶4、m(RAFT-SSO)∶m〔醚(EO和PO)〕=1∶1.15、反应温度75℃、反应时间8 h、引发剂用量为EO(3.45 g)和PO总质量的2%。在上述条件下,RS-EOPO收率为91.8%。

有机硅废触体处理的研究进展

综述了有机硅废触体处理的研究进展,介绍了包括氧化还原回收铜、废触体深度转化和其他用途在内的3种处理方法及其处理效果的影响因素,并展望了有机硅废触体处理的发展方向。

有机硅三元共聚物阻垢剂的制备及性能评价

以环氧琥珀酸、乙烯基三乙氧基硅烷和丙烯酸为原料,偶氮二异丁腈为引发剂,通过共聚反应合成了有机硅三元共聚物(EAVT)阻垢剂。探讨了聚合反应条件对EAVT阻钙垢性能的影响,并对EAVT对单一垢及复合垢的阻垢性能进行了评价。结果表明,较佳合成条件为反应温度65℃、反应时间4 h、引发剂用量6%、环氧琥珀酸、丙烯酸与乙烯基三乙氧基硅烷物质的量之比0.8∶1∶0.8。当EAVT用量为100 mg/L时,其对某油田地层水中钙镁垢和钡锶垢的阻垢率分别为88.28%和87.26%。

Organosilicon modified method to improve Li^+ storage capacity of graphene oxide (GO)

Organosilicon modified reduced graphene oxide(Mr GO) has been fabricated by direct organosilicon modification of graphene oxide(GO). Interestingly,it is observed that 3D rGO-like structures occurred after directly carrying out the organosilicon modification on the surface of GO. The obtained organosilicon Mr GO displays the more remarkable improvement of electrochemical performances than GO,which was verified by electrochemical measurements in detail. For instance,the organosilicon MrGO shows the cycling performances at 901 mA hg^-1 after 200 cycles at 0.1 Ag^-1 and 446 mA hg^-1 after 300 cycles at 2.0 Ag^-1,respectively. These results unveil that organic modification method is an effective way to improve the Li^+ storage capacity of general carbon materials.

Recent advances in synthesis of organosilicons via radical strategies

Organosilicon compounds play an important role in the fields of materials science,pharmacy,and organic synthesis.The development of effective approaches for the preparation of these compounds have also become a research focus in organic synthesis.In recent years,free radical synthesis of organosilicons has been vigorously developed,which generally has the advantages of milder synthesis conditions,higher yields and selectivity,and free of precious metal catalysts compared with traditional strategies.This article reviews research progresses in the synthesis of organosilico n compounds by free radical pathways since 2016.In most cases,the radical silylation is achieved based on the reaction of silyl radicals,which are triggered by four routes including peroxide,transition-metal-induced peroxide decomposition,alkali,photocatalysis.The alkyl radicals can also initiate the radical silylation for the generation of C(sp^(3))—Si bonds.

有机硅高沸物及废触体资源化利用的研究进展

有机硅高沸物及废触体都是有机硅的副产物,前者Cl元素含量高、后者遇空气易自燃,其产量随有机硅行业的高速发展而急剧上升,环保压力不断增大。本文综述了近年来有机硅高沸物及废触体的资源化利用技术,分析了各种技术的优劣势。指出:未来有机硅高沸物及废触体的资源化利用技术可从梯级资源化利用、以废治废、物料循环利用、能量耦合等方面进行整合和升级。

新型有机硅改性聚丙烯酸酯类无氟防水剂的开发及在化纤面料上的应用

文章以自制反应型硅油和丙烯酸酯类防水单体为原料,通过乳液聚合制备了新型有机硅改性聚丙烯酸酯类无氟防水剂,并研究了其在化纤面料上的整理工艺。优化的工艺条件为:该新型无氟防水剂在涤纶春亚纺、涤塔夫、尼丝纺、锦纶塔丝隆面料上的用量分别为20~30、40~60、40~50、30~50 g/L;焙烘温度为170℃,焙烘时间为60 s;其与交联剂搭配使用,选定的涤塔夫、尼丝纺面料在水洗30次后,室温晾干防水性能均可达80分,防水性能及耐洗性能优于市场畅销的无氟防水剂A、无氟防水剂B,且面料色变小,手感好;该新型无氟防水剂适用于大批量面料的防水加工,是无氟防水剂中综合性能突出的新一代产品。

Preparation of Metal Particle Catalysts Wrapped in Organosilicon Compound via Metal Vapor Synthesis

Three kinds of metal catalysts Ni/D4, Ni-Mn/D4, Ni-Mn-La/D4, wrapped in organosilicon compound were prepared by metal vapor synthesis. Their feature was characterized with XRD, TEM, XPS, FMR and static magnetic measurement. The metal particle size in catalysts was less than 3.5 am. The results of XPS showed that the metals in the catalysts existed in zero and other valent state. Inner metal, as an organosilicon compound folded around the metal particle, was protected from oxidation. FMR and static magnetic measuremeat revealed that metal particles were spheroidal and of superparamagnetism. Of all the caralysts the catalytic activity of Ni-Mn-La/D4 was the highest in hydrogenating furfuraldehyde into furfuralcohol.

STUDIES ON ORGANOSILICON REACTIVE INTERMEDIATES (Ⅴ)~*——STEREOSPECIFIC ADDITION OF CYCLOPROPYLPHENYLSILYLENE TO OLEFINS

This paper reports that cyclopropylphenylsilylene (1) is obtained by photolysis of 2-cyclopropyl-2-phenylhexamethyl-trisilane. 1 added stereospecifically to cis-and trans2-butene gives the corresponding siliranes. Opening of the sillranes by methol also occurs in stereospecifically cis fashion.

含硅有机废气预处理剂的开发与应用

在处理含硅有机废气的过程中,由于分解产物覆盖贵金属催化剂活性位点,从而导致催化剂失活。若开发预处理剂,安装在贵金属催化剂前端,可吸附、锚固Si物种,从而保护后端贵金属催化剂,延长VOCs催化剂寿命。本研究利用浸渍后涂覆制备预处理剂,并对样品的效果进行分析,分析结果表明该方法可延长贵金属使用寿命50%以上。