Application of Hydrazine Hydrate in the Synthesis of Octa(aminophenyl)silsesquioxane (OAPS) Poss

Octa(aminophenyl)silsesquioxane (OAPS) was prepared from octaphenyl silsesquioxane (OPS) in two steps, first nitration to obtain Octa(nitrophenyl)silsesquioxane (ONPS) then reduction by using the stable, inexpensive, and readily available hydrazine hydrate as the reducing agent in the presence of Iron(III)Chloride catalyst with a yield of around 87%. Hydrazine is a two-electron reducing agent whereas nitro group is a four-electron reduction process. The activated carbon serves as an adsorbent and electrical conductor enabling the reaction to occur by acting as a mediator between a two-electron reagent and a four-electron process. Adsorption provides a reducing potential and a supply of electrons from many hydrazines making possible the initial four-electron process even though each individual hydrazine is a two-electron donor. The product was characterized by FTIR and 1H NMR. The time period for preparation of ONPS from octaphenyl silsesquioxane was considerably shortened to avoid double nitration of the aromatic rings.

Synthesis and Luminescent Property of Polycarbazole/Polyhedral Oligomeric Silsesquioxane Nanocomposites

Polyvinylcarbazole（PVK） composites containing organic-inorganic hybrid polyhedral oligomeric silse-squioxane（POSS） PVK-POSS were prepared by free radical polymerization. POSS monomers reacted with vinylcarbazole and were completely dispersed at molecular level in PVK matrix and PVK-POSS nanocomposites display higher glass transition temperature（Tg） in comparison with neat PVK. Optical properties of PVK/POSS nanocomposites were investigated by UV-spectrum and PL-spectrum and the results show that the PVK-POSS nanoparticles have a good interface effect and improve color purity effectively. The maximum absorption wavelength bathochromically shifts gradually with the increasing of the content of POSS. The luminescent intensity becomes higher and higher with the increase of POSS content, and reaches its maximum luminescent intensity when the POSS content is 3% （mass fraction）, while some POSS-rich nanoparticles are present in matrix when contents of POSS are beyond 5%.

Synthesis of Silsesquioxane Cages from Phenyl-cis-tetrol, 1,3-Divinyltetraethoxydisiloxane and Cyclopentyl Resins

The synthesis of T_8, T_ 10 and T_ 12 silsesquioxane cages from a range of starting materials: phenyl-cis-tetrol, 1,3-divinyltetraethoxydisiloxane and cyclopentyl T resins by using tetra n-butylammonium fluoride(TBAF) as the catalyst is described in this paper. The reaction yields obtained viathe current route are better compared to those viathe literature routes. Some of the cage compounds have been characterized by X-ray crystallography.

Study of Flame Retardation of Polycarbonate Modified by Polyhedral Oligomeric Silsesquioxane and Caged Bicyclic Phosphate

The flame-retarded polycarbonate（PC） has been made with octaphenyl polyhedral silsesquioxane（OPS） and/or caged bicyclic phosphate（Trimer）.Thermal gravimetric analysis（TGA）,Fourier-transform infrared（FTIR）,TGA-FTIR,limiting oxygen index（LOI）,and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different：OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.

Synthesis and Properties of Organic-Inorganic Hybrid Porous Polymers Obtained with Click Addition Reactions of Thiol-Functionalized Random Type Silsesquioxane by and Diacrylate or Diisocyanate Compounds

Organic-inorganic hybrid network polymers have been synthesized by addition reaction of a thiol-functionalized random type silsesquioxane (SQ109) and alkyl diacrylate or diisocyanate compounds. Thiol-ene reaction of SQ109 and 1,4-butanediol diacrylate (BDA) successfully yield porous polymer in toluene initiated by azobis(isobutyronitrile) (AIBN) at 60°C. Morphology of the porous polymers was composed by connected globules, and the diameter of the globules decreased with increasing in the monomer concentration of the reaction system. By contrast, the reaction with 1,6-hexanediol diacrylate or 1,5-hexadiene yielded homogeneous clear gels. Thermal analyses of SQ109-BDA porous polymers indicated that thermal degradation of ester groups of BDA in the polymer network occurred at around 300°C. The porous polymer was also obtained by the reaction using a photo-initiator (Irugacure184) at room temperature, and showed higher Young’s modulus than the corresponding porous polymer obtained with the reaction with AIBN due to the small size of the globules. Young’s modulus of SQ109-BDA porous polymer increased with increasing in the monomer concentration of the reaction systems. Thiolisocyanate addition reactions between SQ109 and hexamethylene diisocyanate (HDI) or methylenediphenyl 4,4’-diisocyanate (MDI) were investigated to obtain network polymers. The reactions in toluene yielded the corresponding homogeneous clear gels. By contrast the reactions in a mixed solvent of toluene (50 vol.%) and N,N-dimethylformamide (50 vol.%) produced porous polymers. The morphology of the porous polymers was composed by connected globules or aggregated particles. The size of globules and particles in the SQ109-HDI porous polymers was larger than those in the SQ109-MDI porous polymers. Thermal degradation of SQ109-HDI and SQ109-MDI porous polymers started at round 260°C and showed endothermic peak at around 350°C derived from degradation of thio-urethane bond.

Synthesis of cage-like octa(trimethylsiloxy)silsesquioxane

Cage-like octa(trimethylsiloxy)silsesquioxane [(Me3SiO)SiO1.5]8 has been synthesized via the trimethylsilylation of cubic tetramethylammonium silicate octamer [(Me4NO)-SiO1.5]8 with chlorotrimethylsilane. The silicate octamer can be selectively formed by the reaction of tetraethoxysilane Si(OEt)4 with aqueous tetramethylammonium hydroxide in equal

ORGANIC/INORGANIC HYBRID EPOXY NANOCOMPOSITES BASED ON OCTA(AMINOPHENYL)SILSESQUIOXANE

Octa（aminophenyl）silsesquioxane （OAPS） was used as the curing agent of diglycidyl ether of bisphenol-A （DGEBA） epoxy resin. A study on comparison of DGEBA/OAPS with DGEBA/4,4＇-diaminodiphenyl sulfone （DDS） epoxy resins was achieved. Differential scanning calorimetry was used to investigate the curing reaction and its kinetics, and the glass transition of DGEBA/OAPS. Thermogravimetric analysis was used to investigate thermal decomposition of the two kinds of epoxy resins. The reactions between amino groups and epoxy groups were investigated using Fourier transform infrared spectroscopy. Scanning electron microscopy was used to observe morphology of the two epoxy resins. The results indicated that OAPS had very good compatibility with DGEBA in molecular level, and could form a transparent DGEBA/OAPS resin. The curing reaction of the DGEBA/OAPS prepolymer could occur under low temperatures compared with DGEBA/DDS. The DGEBA/OAPS resin didn＇t exhibit glass transition, but the DGEBA/DDS did, which meant that the large cage structure of OAPS limited the motion of chains between the cross-linking points. Measurements of the contact angle indicated that the DGEBA/OAPS showed larger angles with water than the DGEBA/DDS resin. Thermogravimetric analysis indicated that the incorporation of OAPS into epoxy system resulted in low mass loss rate and high char yield, but its initial decomposition temperature seemed to be lowered.

Synthesis of Ladder-like Polyphenylsilsesquioxanes with Fairly High Regularity Using 1,2-Ethylenediamine as Endo-template

Ladder-like polyphenylsilsesquioxanes with fairly high regularity were synthesized using an endo-template 1,2-ethylenediamine at mild temperature via direct co-hydrolysis and condensation reactions in the presence of acid catalysts in the mixture of 1,4-dioxane/H20. The features for synthesis of ladder-like polyphenylsilsesquioxanes were investigated in detail. The products obtained were characterized by FTIR, SEC, XRD and NMR.

Ultrasmall Nanoparticle ROS Scavengers Based on Polyhedral Oligomeric Silsesquioxanes

Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.

Arylazopyrazole-functionalized photoswitchable octanuclear Zn(Ⅱ)-silsesquioxane nanocage

Photoswitchable organic materials have shown significant advancement for photonic applications,however,the polynuclear metal clusters conjugated with photoswitching properties are still formidable.Herein,a novel octanuclear Zn(Ⅱ) nanocage{[Zn_(8)-(Me_(4)Si_(4)O_(8))_(2)(azopz)_(8)]·4CH_(2)Cl_(2)·MeOH·MeCN}(SD/Zn8)(Hazopz=3,5-dimethyl-4-(phenyldiazenyl)-1H-pyrazole),based on multidentate silsesquioxane and pyrazole modified by photoisomerizable azo group has been designed and synthesized to realize the reversible photoswitching behavior.X-ray crystallographic study reveals that the unique metal core consists of two annular Me_(4)Si_(4)O_(8)^(4-)sandwiching a ring of eight Zn atoms where the pyrazole end of azopz-bridges them together.The azopz-ligands diverge above and below the plane defined by eight Zn atoms.Importantly,SD/Zn8 shows quick trans-to-cis transformation upon 365 nm light irradiation,which can be easily changed back by 450 nm light,but slow cis-to-trans reversibility at room temperature as confirmed by UV-V is and 1H NMR spectroscopies.This process,which presumably regulates the spaces,acts like a pump and is completely repetitive.As such,it can be considered as a molecular pump energized by light.Importantly,the molecule is an energy reservoir where it absorbs the light energy and releases it slowly with time.

Three-dimensional configurations of organic/inorganic hybrid nanostructural blocks (I).A quantum mechanical investigation for ladder-like structure of vinylsilsesquioxane

The organic/inorganic hybrid nanostructural vinylsilsesquioxanes (VSSO) were prepared from the hydrolytic condensation of vinyltrimethoxysilane (VMS). The proposed formu- las of VSSO were assigned with standard spectroscopic techniques, FTIR, NMR (1H, C and 13 29Si) and MALDI-TOF MS, and a generic formula of the SSO, Tn(OH)x(OR’)y(x, y = 0, 1, 2…; n = 1, 2…; T = RSiO1.5 ?(x+y)/2n). Geometric parameters (Si-O and Si-C bond lengths, Si-O-Si and O-Si-O bond angles) and total energies of the multi-structures of VSSO were calculated by a quantum mechanical investigation and molecular symmetries. According to the results of the calculation, most molecules had stabler ladder structures than the cage isomers, therefore, the most probably reasonable and optimum structure of the VSSO system was the ladder type.

Synthesis of peptide dendrimers with polyhedral oligomeric silsesquioxane cores via click chemistry

Inorganic polyhedral oligomeric silsesquioxane （POSS） was used as the core for the synthesis of poly（t- lysine） peptide dendrimer via copper-catalyzed azide-alkyne click chemistry. The inorganic/organic composite dendrimer was characterized by MS, 1H NMR, FTIR, GPC and DLS.

Bridged polyhedral oligomeric silsesquioxane(POSS):A potential member of silsesquioxanes

Two novel and well-defined polyhedral oligomeric silsesquioxanes（POSS） with two same Si_8O_（12） cores and a reactive NH group, namely bridged-POSS（2a and 2b）,have been prepared by the traditional ＇corner-capping＇ reaction.X-ray diffraction demonstrates that those two POSS have the similar T_8 structure.From the thermo-gravimetric analysis,bridged-POSS shows the belter thermal degradation stability than the contrastive POSS.

Positive Luminescent Sensor for Aerobic Conditions Based on Polyhedral Oligomeric Silsesquioxane Networks

There are numerous numbers of hypoxia-selective luminescent probes based on oxygen quenching of phosphorescence.We show a unique design for luminescent probes to detect hyperoxia utilizing hybrid networks consisting of aggregation-induced emission(AIE)-active dyes and disulfide linkers.At the initial state,emission from the AIE-active dyes is inducible by suppressing energy-consumable intramolecular motions in the hybrid matrices,while the decrease in intensity was detected by releasing molecular motions corresponded to bond scission at the disulfide linkers.Particularly,it was shown that this process selectively proceeds in hypoxia.As a result,positive luminescent signals were obtained in hyperoxia.

Effect of Polyhedral Oligomeric Silsesquioxane and Sorbitol on Properties of Isotactic Polypropylene

Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- propyl-heptaisobutyl POSS with DMDBS（POSS-DMDBS）, and physical mixing of DMDBS with octaisobutyl POSS （iso-POSS/DMDBS） or trisilanolisobutyl POSS（tri-POSS/DMDBS） were applied respectively to modifying iPP, and the effects of POSS and DMDBS on crystallization, rheological and mechanical properties of iPP were systematically investigated. The results indicate that iso-POSS/DMDBS and tri-POSS/DMDBS were more effective than POSS-DMDBS on the improvement of the crystallization behavior of iPP due to the higher crystallization temperature, while the crystal!inity of iPP containing POSS-DMDBS was enhanced, approximately approached to that of iPP containing tri-POSS/DMDBS. The tensile strength of iPP with POSS-DMDBS was significantly increased from 34 MPa to 40 MPa, as high as that of iPP with iso-POSS/DMDBS. The different effects caused by the specific interaction between POSS and DMDBS could possibly be applied in the modification of iPP.

Effectiveness of an ocular adhesive polyhedral oligomeric silsesquioxane hybrid thermo-responsive FK506 hydrogel in a murine model of dry eye

Dry eye is a common ocular disease that results in discomfort and impaired vision,impacting an individual’s quality of life.A great number of drugs administered in eye drops to treat dry eye are poorly soluble in water and are rapidly eliminated from the ocular surface,which limits their therapeutic effects.Therefore,it is imperative to design a novel drug delivery system that not only improves the water solubility of the drug but also prolongs its retention time on the ocular surface.Herein,we develop a copolymer from mono-functional POSS,PEG,and PPG(MPOSS-PEG-PPG,MPEP)that exhibits temperature-sensitive sol-gel transition behavior.This thermo-responsive hydrogel improves the water solubility of FK506 and simultaneously provides a mucoadhesive,long-acting ocular delivery system.In addition,the FK506-loaded POSS hydrogel possesses good biocompatibility and significantly improves adhesion to the ocular surface.In comparison with other FK506 formulations and the PEG-PPG-FK506(F127-FK506)hydrogel,this novel MPOSS-PEG-PPG-FK506(MPEP-FK506)hydrogel is a more effective treatment of dry eye in the murine dry eye model.Therefore,delivery of FK506 in this POSS hydrogel has the potential to prolong drug retention time on the ocular surface,which will improve its therapeutic efficacy in the management of dry eye.

Facile generation of highly durable thiol-functionalized polyhedral oligomeric silsesquioxane based superhydrophobic melamine foam

In this study,a durable superhydrophobic/superoleophilic melamine foam was fabricated by a facile and rapid one-step thiol-ene click chemistry and Michael addition reaction,which demonstrated excellent robustness in oil/water separation.First,1H,1H,2H-perfluoro-1-hexene reacted with thiol-functionalized polyhedral oligomeric silsesquioxane via the thiol-ene click chemistry to obtain a fluorinated thiol-functionalized polyhedral oligomeric silsesquioxane solution.Subsequently,the melamine foam was immersed to the solution system to form nanoaggregates on the melamine foam surface by the Michael addition reaction in the presence of ultraviolet light.The micro/nano rough structure and low surface energy of the nanoaggregates layer endowed the pristine melamine foam with superhydrophobicity;the water contact angle was greater than 150°.More importantly,the as-prepared melamine foam could withstand harsh conditions,such as a corrosive solution environment,strong ultraviolet light,mechanical compression,high and low temperature exposure,and ultrasonic washing.Driven by gravity,the as-prepared melamine foam could efficiently separate the oil/water mixtures and maintain 98%separation efficiency at high and low temperatures.In addition,it maintained the desirable absorption capability in different oil/organic solvents even after 15 absorption cycles.Accordingly,this facile,low-cost,and robust onestep method provides important support for the superhydrophobic oil/water separation field.

Latest developments in EUV photoresist evaluation capability at Shanghai Synchrotron Radiation Facility

Evaluating the comprehensive characteristics of extreme ultraviolet(EUV)photoresists is crucial for their application in EUV lithography,a key process in modern technology.This paper highlights the capabilities of the Shanghai Synchrotron Radiation Facility(SSRF)08U1B beamline in advancing this field.Specifically,it demonstrates how this beamline can create fringe patterns with a 15-nm half-pitch on a resist using synchrotron-based EUV lithography.This achievement is vital for evaluating EUV photoresists at the advanced 5-nm node.We provide a detailed introduction to the methods and experimental setup used at the SSRF 08U1B beamline to assess an EUV photoresist.A significant part of this research involved the fabrication of high-resolution hydrogen silsesquioxane mask gratings.These gratings,with an aspect ratio of approximately 3,were created using electron beam lithography on an innovative mask framework.This framework was crucial in eliminating the impact of zeroth-order light on interference patterns.The proposed framework propose offers a new approach to mask fabrication,particularly beneficial for achromatic Talbot lithography and multicoherent-beam interference applications.

HSQ用于电子束曝光的性能分析

作为一种非化学放大的无机负性电子束光刻抗蚀剂,HSQ(hydrogen silsesquioxane)具有极高的分辨率(约5 nm),由于灵敏度较低,限制了其在微纳米加工方面的应用。从化学结构变化的角度分析了HSQ在电子束曝光中的性能,通过实验验证了其灵敏度及对比度受前烘温度及显影液浓度的影响较大,并且其在电子束曝光中的邻近效应也可以通过改变这两个条件而得到一定的抑制。根据所得优化工艺条件,在450 nm胶层上,制作出100 nm等间距光栅结构胶层图形,且其侧壁陡直性良好。