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para-Substituted bis(3-aminopropyl)hexaisobutyl-cage octasilsesquioxane (T8 cage) (1) was polymerized with several diisocyanates; methylenediphenyl 4,4’-diisocyanate (2a), 4,4’-diisocyanato-3,3’-dimethylbiphenyl (2b), m-xylene diisocyanate (2c), 1,3-bis(isocyanatomethyl)cyclohexane (2d), tolylene-2,4-diisocyanate (2e), and tolylene-2,6-diisocyanate (2f), at room temperature to prepare T8-polyureas (3). Gel formation was observed immediately during the addition of 2 to the solution of 1 when above the critical gel concentrations (Cgs). T8-polyureas with phenylurea moieties, 3a, 3b, 3e, and 3f, promoted organogel formation in comparison with T8-polyureas with nonphenylurea moieties, 3c and 3d. The substitution of methyl groups at the ortho position of the phenylurea groups provided lower Cgs. FT-IR analysis suggests that increasing the intermolecular hydrogen bonding between the ureido groups in T8-polyurea enhanced the organogel formation. We also studied the POSS structure-dependent properties of the polyureas, in which the T8 cages were replaced by double-decker-shaped phenyl-substituted silsesquioxane (DDSQ) units. Polymerization was conducted at various concentrations, and it was found that no organogels were formed below the solubility limit of the monomers except when 2f was used. This observation suggests that the polyureas containing the isobutyl-substituted T8 units promoted organogel formation in comparison with those containing DDSQ units. Organogel formation was observed immediately during the addition of diisocyanate to a solution of para-substituted bis(3-aminopropyl)hexaisobutyl-substituted cage octasilsesquioxane (T8 cage) monomer at room temperature when above the critical gel concentrations (Cgs). T8-polyureas with phenylurea moieties promoted organogel formation in comparison with T8-polyureas with nonphenylurea moieties. The substitution of methyl groups at the ortho position of the phenylurea groups provided lower Cgs. Increasing the intermolecular interaction between the ureido groups in the T8-polyurea enhanced organogel formation, which was supported by the FT-IR analysis of the dried gels.

Purpose The present research aims to manage the formulations of pigment-based inks containing aminopropyl/vinyl/silsesquioxane (APSV) as a pigment binding agent for inkjet printing of polyester as a commercial trial for the printing of polyester as a single-step process. Design/methodology/approach The proposed formulations incorporated APSV by using the mini-emulsion technique at a low relieving temperature under the thermal initiation or UV radiation of vinyl-terminated groups in APSV. In this study, the storage stability of inks with regard to physical properties was broadly examined. Moreover, the color performance, including colorimetric data, color fixation and fastness properties of printed fabrics was evaluated. Findings The results indicated that the inks containing APSV were formulated and were stable in terms of particle size, dispersion stability, surface tension and viscosity over a period of one month and for four freeze/thaw cycles. APSV successfully fixed the pigment-based inkjet inks on polyester fabric and could achieve a significantly higher color performance and degree of fixation than the formulated inks without APSV. Research limitations/implications It could also fulfill all the physical properties of ink prerequisites over storing and eliminating all challenges in improving the performance and utilization of inkjet printing. Practical implications APSV can also be used as a pigment binding agent to formulate inks for inkjet printing of polyester fabrics as the authors’ past examination for inkjet printing of polyester fabrics post-treated with APSV. Social implications This study eliminates the noteworthy challenges in formulating the pigment-based inks for textile applications by incorporation of a binder while keeping up the necessary viscosity profile for a specific print head. Originality/value This study addressed all the issues arising from the complex nature and very challenging requirements of inkjet inks.

Epoxy-polyhedral oligomeric silsesquioxane (POSS) nanocomposites were prepared by incorporating POSS nanofiller into the epoxy-amine network. The monofunctional epoxy-POSS monomer or nonfunctional ...

Cosolvent-free (solventless) hydrolytic polycondensation of fluoroalkyltrimethoxysilanes of linear fluoroalkyl groups of the form R = CnF2n+1C2H4 (n = 1, 4, and 8) and methyltrimethoxysilane followed by thermal curing yielded dense polymeric silsesquioxane (SQ) resins with low refractive indices and deep-ultraviolet transparency with an ultraviolet absorption edge at ∼210 nm. The refractive index at 589 nm was adjustable at ∼1.35-1.39, and the lowest value was ∼1.354 for the stiff resin and ∼1.347 for the soft resin of poly(R-co-Me-SQ) prepared at n = 8. The refractive indices of these resins were consistent with the linear combinations of molar refractivities of constituent functional groups, and there were no free-volume anomalies.

The aim of this study was to produce crosslinked low-density polyethylene (LDPE) composites using peroxide and octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) and to examine the shape memor...

To study the influences of 3-amino-polyhedral oligomeric silsesquioxane (NH2-POSS) on the properties of waterborne polyurethanes (WPU), a series of NH2-POSS modified WPUs were synthesized by using polypropylene glycol (PPG-2000, PPG-310), 2,2-dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), and NH2-POSS via a one-pot reaction and a high shear emulsification method. The results showed that when the NH2-POSS amount in the WPU/NH2-POSS nanoemulsion was 5.73 wt% (WPU2, based on the weight of WPU resin), its viscosity was 2.496 MPa · s and its Zeta potential was 63.7 mV(pH = 6.1), showing lower viscosity and better dispersion stability. The particle size of WPU2 is smaller than that of WPU0, and the polydispersion index (PDI) of WPU2 was decreased from 5.520 to 3.837 indicating a higher crosslinking density. In addition, the thermal stability of WPU/NH2-POSS nanoemulsion was increased with the content of NH2-POSS from 0.00 to 13.19%. The water contact angle values for the WPU2 (84.5°) were higher than that of WPU0 (80.2°), showing an improvement of the hydrophobic properties. This WPU/NH2-POSS nanocomposites can be used for making coating adhesive for textile and hosting matrix for making multifunctional nanocomposites.

Polyhedral oligomeric silsesquioxane (POSS) is a versatile building block for various organic/inorganic hybrid materials. However, its intrinsic reactivity has attracted limited attention, particularly in polymer chemistry. This study investigated the cage-scrambling properties of POSS-pendant random copolymers catalyzed by fluoride anions, leading to gelation of a solution of random copolymers. A series of POSS-pendant random copolymers was prepared using POSS-containing methacrylates and several vinyl monomers. The gelation properties were first investigated in detail using P(PhPOSSMA-r-BMA) by varying the POSS content and reaction conditions. The insoluble product was characterized by FT-IR and solid-state 29Si-NMR, the results of which support the intermolecular cage-scrambling reaction of the pendant POSS moieties via transient siloxane cleavage. Chloride and bromide anions also acted as catalysts for the scrambling reaction. Altering the comonomer or the vertex substituents resulted in varying gelation times depending on each structural characteristic. The unique polymer reaction presented herein opens up a wider range of uses for POSS—not only as an inorganic component but also as an intrinsically reactive moiety in various organic/inorganic hybrid polymer materials. Fluoride anions-catalyzed cage scrambling and gelation of POSS-pendant random copolymers was investigated. A series of POSS-pendant random copolymers was prepared using POSS-containing methacrylates and several vinyl monomers. FT-IR, solid-state 29Si-NMR, and swelling experiments of the gelation products showed that the pendant POSS groups underwent intermolecular cage-scrambling reaction, which proceeds via transient siloxane cleavage. Chloride and bromide anions also catalyzed the scrambling reaction under modified reaction conditions. Gelation properties depended on various factors such as the comonomers, reaction solvents, vertex substituents, POSS contents, and catalyst feeds.

This paper reports the synthesis and characterization of a silsesquioxane polymer based on a rigid silica inorganic core and 3-n-propyl(4-methylpyridinium) organic linker (Si-4Pic+Cl‒), an organic–inorganic hybrid material which showed great potential for the application as an adsorbent for 4-nitrophenol (4-NP), a hazardous organic compound. The silsesquioxane material was fully characterized by ATR-FTIR, solid-state 13C-NMR, and 29Si-NMR, TGA, potentiometric chloride titration and carbon, hydrogen, and nitrogen elemental analyses (CHN). The effect of pH, contact time on adsorption performance of Si-4Pic+Cl‒ to 4-NP and heterogeneous adsorption equilibrium were investigated systematically. The remarkable adsorption affinity of 4-NP onto Si-4Pic+Cl‒ obeys the Langmuir model and a π–π stacking interaction between adsorbent and adsorbate was proposed. Cycle rate experiments demonstrated that the ability to be recovered and reusable at least three times makes this silsesquioxane material a very promising adsorbent of noxious 4-NP in aqueous media.

In this study, the compatibilization effects of triglycidylisobutyl polyhedral oligomeric silsesquioxane (TEpPOSS) on biodegradable poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were investigated. All blends were prepared via melt blending and PLA/TPU (80/20, 70/30, 50/50 wt%) ratio was selected as the experimental parameter. In order to predict the selective localization of TEpPOSS thermodynamically, wetting coefficient were determined by means of surface energy measurements. Morphological analyses were carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, rheological, mechanical, thermomechanical and thermal properties of the blends were performed via rheometer, universal tensile tester, dynamic mechanic analyses and differential scanning calorimeter (DSC), respectively. Morphological test results revealed that TEpPOSSs were mostly located at the interfaces of the PLA and TPU phases. According to the rheological studies, the interfacial interactions between PLA and TPU were improved with the addition of TEpPOSS, which resulted from the potential reactions between epoxy-carboxylic acid and/or epoxy-hydroxyl functional groups. The addition of TEpPOSS enhanced the mechanical properties of PLA/TPU blends. DSC test results revealed a decrease in the glass transition temperatures of PLA in the presence of TEpPOSS, which was an another indication of improved compatibility between PLA and TPU.

In this study, the multi-wall carbon nanotubes (MWCNTs) were grafted with Octa (propyl glycidyl ether) polyhedral oligomeric silsesquioxane (GOPOS) to form GOPOS-G-MWCNTs prior to use as an additive for improving the mechanical and the flame-retardant characteristics of the epoxy resin (EP). The surface of MWCNTs was also modified with a silane coupling agent before conducting the grafting reaction. The Fourier-transform infrared spectroscopy technique was applied to confirm the success of the grafting reaction. The epoxy-based composite materials were performed at room temperature using diethylenetriamine (DETA) as a hardener. Many characteristics of these materials were examined such as tensile strength, thermal stability, flammability, and fracture surface morphology. The presence of GOPOS-G-MWCNTs helped to reduce the total heat release, the peak of heat release rate (pHRR), and total smoke release by 68.68, 47.69, and 11.78%, respectively. While the tensile strength and fracture energy were also increased up to 30 and 102% when compared with virgin EP. The good dispersion of GOPOS-G-MWCNTs and char residue effect were considered as the main reasons for these improvements. A mechanism for enhancing flame-retardant behaviors of EP was also proposed .

This work describes the preparation and use of a polydimethylsiloxane sponge amino functionalized for the adsorption of copper in water. The sponge was structurally characterized by infrared spectroscopy and solid-state 29Si NMR, which indicated the presence of silsesquioxane units that acted as nodes on the PDMS chains and linked the functional groups to the network. Thermogravimetric analysis of the product showed good thermal stability, with the initial temperature of weight loss at 400 °C. The material displayed a high degree of swelling in polar solvent, presumably due the cavities. The presence of the amino group increases the adsorption of copper onto the surface of the sponge, with adsorption capacity of about 2.0 mmol (127 mg) per gram of material. The sponge shows promising results for environmental remediation with the removal of copper in water, as well as a simple utilization with no need of a separation process after metal adsorption.

In this paper, the laboratory-synthesized single-component intumescent flame retardant (IFR) and the phosphorus-containing polyhedral oligomeric silsesquioxane (P-POSS) as a novel synergist were co...

The addition of methacrylate-functional polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles to styrene-butadiene rubber (SBR) composites was evaluated in terms of rheological, mechanical, and morphological properties. The aging process and cross-link density of rubber nanocomposites were examined in presence of MA-POSS. The MA-POSS could directly participate in the vulcanization reaction due to its methacrylate groups and its concentration affected the rheological and mechanical properties of rubber. The sulfur vulcanization characteristics of MA-POSS/SBR nanocomposites were determined by moving die rheometer. It was indicated that the addition of MA-POSS to SBR composites retarded the curing time and decreased the cross-link density. Due to an effective interaction between MA-POSS nanofiller and SBR matrix and excellent dispersion of POSS, the mechanical properties of nanocomposites were higher than those of the reference compound without MA-POSS. However, there was no significant change investigated in tensile retention in presence of MA-POSS. The presence and the random distribution of MA-POSS in SBR matrix was confirmed by TEM analysis. The cross-link densities of the composites, which were calculated using Flory–Rehner equation, decreased with increasing amount of POSS nanofiller. It was finally revealed that the thermal aging dramatically reduced the mechanical properties and cross-link density of MA-POSS/SBR nanocomposites.

Organosilsesquioxane hybrid materials are an important class of functional materials due to their tailorable functions and high thermal and optical stability. Recently, several studies showed that ...

The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully developed. For the first step, using 1-vinyl-3-dodecylimidazole bromide (VDI·Br) and polyhedral oligomeric silsesquioxane methacryl substituted (POSS-MA) as monomer and crosslinking agent, the monolithic POSS-VDI matrix material was polymerized in 100 μm capillary. The prepared POSS-VDI column is of ion-exchange/reverse-phase mixed-mode retention characteristics. The column efficiency reached 137,000 N/m for thioureas. The POSS-VDI column has also been successfully applied to recognize and analyze the effective components of Traditional Chinese Medicines Fangji and the Root of Kudzu Vine. Furthermore, based on its good chromatographic performances, in the second step, amino acids l-Proline (l-Pro), Glycine (Gly) or DL-Phenylalanine (DL-Phe) were further exploited as the anion exchangers to post-modify the POSS-VDI column. The new POSS-VDI-Pro, POSS-VDI-Gly and POSS-VDI-Phe columns exhibited different separation selectivity for the complex egg white protein sample. The present work provides a good route to fabricate versatile amino acids and ionic liquids modified monolithic columns with good separation selectivity.

Nowadays, there is a need for a paradigm shift in material selection for surface coatings so as to meet the requirements of advanced systems. Polyhedral oligomeric silsesquioxanes (POSS) are three-dimensional networks with a silica-like core covered by an organic shell, a promising nanosized structure for organic coatings. The use of POSS structures in coating materials has experienced an almost erratic period over the past decade, mainly because of the synthesis of POSS being exclusive and, to some extent, expressive. However, there has been a big return to the use of POSS in coatings during the last years. Epoxy is best known for its versatility of usage as an organic coating. Hybrid organic–inorganic POSS nanostructures with unique properties are a complement to the epoxy for coating applications. The tailorable compatibility and considerable reactivity of POSS molecules towards organic groups have made them promising candidates for emerging multifunctional epoxy coatings. In this sense, the focus of this review is placed on POSS/epoxy nanocomposite coatings. The thermal, mechanical, anti-corrosion and dielectric properties of POSS/epoxy coatings have been comprehensively studied and discussed.

Polyhedral oligomeric silsesquioxane (POSS) is an inorganic-organic nanostructure. POSS nanocage possesses silica core and organic functionalities at corners. POSS has been familiarized with variou...

Double-decker silsesquioxane (DDSQ), a type of incompletely condensed silsesquioxane, has been used as a molecular precursor for synthesizing new organotin discrete and oligomeric compounds. The equimolar reaction between DDSQ tetrasilanol (DDSQ-4OH) and Ph2SnCl2 in the presence of triethylamine leads to obtaining discrete [Ph4Sn2O4(DDSQ)(THF)2] (1). The change of sterically bulky aryl Ph2SnCl2 precursor to linear alkyl nBu2SnCl2 led to the isolation of oligomeric [nBu4Sn2O4(DDSQ)] (2). The structures of compounds 1 and 2 have been demonstrated using single-crystal X-ray diffraction measurements. Indeed, the formation of oligomeric organotin DDSQ compound (2) was determined using GPC and MALDI-TOF mass spectroscopy. In compound 1, the geometry of the tin atom is five-coordinated trigonal bipyramidal by two phenyl groups, two Si–O from DDSQ and one tetrahydrofuran. Compound 2 contains four coordinated two peripheral tin atoms and two five-coordinated central tin atoms, in which, the fifth coordinating oxo groups in the central tin atoms create the bridge between two different DDSQ units that leads to the formation of oligomeric structure. Density functional theory calculations on organotin DDSQs infer that the obtained lattice energy for compound 1 is far higher than for the case of compound 2, which indicates that the crystal of compound 1 is better stabilized in its crystal lattice with stronger close packing via intermolecular interactions between discrete molecules with coordinated THF compared to the crystal of compound 2. The greater stability arises mainly due to the sterically bulkier phenyl groups attached to the tin centers in compound 1, which provide accessibility for accommodating the THF molecule per tin via Sn–THF bonding, while contrarily the smaller n-butyl groups aid the polymerization of the four repeating units of [SnSi4O7] or two Sn2O4(DDSQ) through μ-oxo groups. Both compounds 1 and 2 were chosen to be promising precursors for the synthesis of ceramic tin silicates. The thermolysis of 2 at 1000 °C afforded the mixture of crystalline SnSiO4 and SiO2 but the same mixture was only formed by thermolysis of 1 at relatively higher temperature (1500 °C), which infers that compound 1 is more stable than compound 2 that is in good synergy with theoretical lattice energy.

Octasilsesquioxane cages with co-substituent characteristics were synthesized through polyhydrolytic–condensation reactions involving two mixed monomers, namely i-butyl(triethoxysilane) and organotrialkoxysilanes (e.g., phenyl, vinyl, ethyl, propyl, and 3-chloropropyl groups). Only mild and simple methods were required to obtain crystalline products as all products consisted octameric silsesquioxane (T8) cubes with normal distribution between i-butyl and other substituents. The formation was confirmed by NMR and ESI-MS spectra. The i-butyl group on the silane monomer was not only a controller to yield cage-like structural products with mixed substituents, but also their highly symmetrical Oh in the cubic Si–O core, which drives the product separation through crystallization. The crystalline structure of the products was validated by the correlation between the endothermic peak at the melting temperature (Tm) from the DSC analysis and sharp peaks observed in the XRD diffraction patterns.

Luminescent cyclometallated iridium(III) complexes with a polyhedral oligomeric silsesquioxane (POSS) unit were designed as efficient theranostic agents that displayed tuneable organelle-targeting properties, minimal dark cytotoxicity and substantial photocytotoxicity even under hypoxic conditions.

We have successfully synthesized a series of monodispersed chain-like giant molecules with precisely controlled macromolecular composition and sequence based on polyhedral oligomeric silsesquioxane (POSS) nanoparticles using an orthogonal “click” strategy. Their nonspherical supramolecular structures, such as lamellae, double gyroids, and hexagonal packed cylinders, are mainly determined by the composition (namely, the number of incorporated amphiphilic nanoparticles). In addition, by precisely alternating the sequence of arranged nanoparticles in the giant molecules with identical chemical compositions, the domain sizes of their supramolecular structures could be fine-tuned. This is attributed to the macromolecular conformational differences caused by collective hydrogen bonding interactions in each set of sequence isomeric giant molecules. This work has demonstrated multilevel manipulation of supramolecular structures of giant molecules: coarse tuning by composition and fine-tuning by sequence.

Nanostructured solid electrolytes containing ion-conducting domains and rigid nonconducting domains are obtained by block copolymer self-assembly. Here, we report on the synthesis and characteristics of mixtures of a hybrid diblock copolymer with an organic and inorganic block: poly(ethylene oxide)-b-poly(acryloisobutyl polyhedral oligomeric silsesquioxane) (PEO–POSS) and a lithium salt. In the neat state, PEO–POSS exhibits a classical order-to-disorder transition upon heating. Dilute electrolytes exhibit a dramatic reversal; a disorder-to-order transition upon heating is obtained, indicating that the addition of salt fundamentally changes interactions between the organic and inorganic chains. At higher salt concentrations, the electrolytes primarily form a lamellar phase. Coexisting lamellae and cylinders are found at intermediate salt concentrations and high temperatures. The conductivity and shear modulus of PEO–POSS are significantly higher than that of an all-organic block copolymer electrolyte with ...

A series of shape amphiphiles based on functionalized polyhedral oligomeric silsesquioxane (POSS) head tethered with two polymeric tails of symmetric or asymmetric compositions was designed and synthesized using sequential "grafting-from" and "click" surface functionalization. The monofunctionalization of octavinylPOSS was performed using thiol-ene chemistry to afford a dihydroxyl-functionalized POSS that was further derived into precisely defined homo- and heterobifunctional macroinitiators. Polymer tails, such as polycaprolactone and polystyrene, could then be grown from these POSS-based macroinitiators with controlled molecular weight via ring-opening polymerization and atom transfer radical polymerization (ATRP). The vinyl groups on POSS were found to be compatible with ATRP conditions. These macromolecular precursors were further modified by thiol-ene chemistry to install surface functionalities onto the POSS cage. The polymer chain composition and POSS surface chemistry can thus be tuned separately in a modular and efficient way.

This letter reports a sequential triple “click” chemistry method for the precise synthesis of functional polyhedral oligomeric silsesquioxane (POSS)-based multiheaded and multitailed giant surfactants. A vinyl POSS-based heterobifunctional building block possessing two alkyne groups of distinct reactivity was used as a robust and powerful “clickable” precursor for ready access to a variety of POSS-based shape amphiphiles with complex architectures. The synthetic approach involves sequentially performed strain-promoted azide–alkyne cycloaddition (SPAAC), copper-catalyzed azide–alkyne cycloaddition (CuAAC), and thiol–ene “click” coupling (TECC). Specifically, the first SPAAC reaction was found to be highly selective with no complications from the vinyl groups and terminal alkynes in the precursor. The method expands the toolbox of sequential “click” approaches and broadens the scope of synthetically available giant surfactants for further study on structure–property relationships.

A new polyhedral oligomeric silsesquioxane (POSS) methacrylate monomer, 1-(3-(methacryloyloxy)propyl)dimethylsiloxy-3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13,9.15,15.17,13]octasiloxane ((i-Bu)7POSS-OSiMe2-MA, 1), with a flexible spacer between the cubic POSS cage and methacrylate group was synthesized to reduce steric strain and thus achieve polymethacrylates (poly(POSS-MA)s) with high molecular weight (MW). Atom transfer radical polymerization (ATRP) of 1 at high monomer concentration (1 M, corresponding to ca. 85 wt % of 1) led to polymers with the absolute number-average MW, determined by multiangle laser light scattering, Mn,MALLS = 2 350 000 (and apparent MW, measured by gel permeation chromatography with linear poly(methyl methacrylate) (PMMA) standards, Mn,GPC = 550 000). Optimization of the reaction conditions, including the ATRP catalyst, targeted degrees of polymerization, monomer concentrations, as well as a monomer feeding, resulting in the first well-defined high MW polymers with P...

Rapid and precise synthesis of macromolecules has been a grand challenge in polymer chemistry. In this letter, we describe a convenient, rapid, and robust strategy for a one-pot synthesis of various precisely defined giant surfactants based on polyhedral oligomeric silsesquioxane (POSS). The method combines orthogonal oxime ligation, strain-promoted azide–alkyne cycloaddition (SPAAC), and thiol–ene “click” coupling. The process is usually completed within 0.5–2 h and does not require chromatography methods for purification. With near quantitative conversion efficiency, the method yields giant surfactants with distinct topologies, including single-tailed and asymmetric, multitailed giant surfactants. Both polymer tail composition and POSS surface chemistry are controlled precisely and tuned independently, enabling the design and preparation of new classes of giant surfactants.

A total of 1/2/4/6-armed molecular architectured polyhedral oligomeric silsesquioxane (POSS) fluoropolymers were synthesized via atom transfer radical polymerization (ATRP) by linear (L), dicephalus (D), four-arm (T), and six-arm (S) initiators initiating same content of methyl methacrylate (MMA), methacrylate POSS (MA-POSS), and dodecafluoroheptyl methacrylate (DFHM). The obtained L/D/T/S-(PMMA-b-PMAPOSS-b-PDFHM)1/2/4/6 had increased molecular weight with arm increase. Driven by the stereo-hindrance and curvature effects of segments in tetrahydrofuran (THF), they assembled into the decreased spherical core-shell micelles (250–100 nm) with arm increase as PMA-POSS/PDFHM core and PMMA shell. Because of easy surface migration of fluorine-containing groups in small micelles, the casted film by S-(PMMA-b-PMAPOSS-b-PDFHM)6 performed the fluorine-rich (46.44%) and rough (5.41 nm) surface, and therefore with the hydrophobic (112°) and low water adsorption surface (1522 ng/cm2). Also, POSS-fluoropolymers obtained the enhanced thermostability with arm increase. It is believed that this research will provide a bright view for design and application of POSS-fluoropolymers.

Sixteen-arm star-shaped polymer of s-POSS-(PDMAEMA)16 was synthesized by octakis(dibromoethyl) polyhedral oligomeric silsesquioxane (POSS-(Br)16) initiating 2-(dimethylamino)ethyl methacrylate (DMAEMA) via atom transfer radical polymerization (ATRP) process. The obtained s-POSS-(PDMAEMA)16 showed controllable and reversible pH-responsive behavior at pH = 1–12 and thermoresponsive behavior at 20–60 °C. Typical core/shell micelles (100–130 nm) were formed by s-POSS-(PDMAEMA)16 at pH = 7.8 and transformed into 450–600 nm snowflake-shaped micelles at pH = 6, 400 nm butterfly-shaped micelles at pH = 3, and 20–40 nm spherical particles at pH = 10 due to the different interactions between the PDMAEMA chains and the aqueous solution. When the pH of the solution decreased from 10 to 3, 350–400 nm butterfly-shaped micelles were reformed, demonstrating the reversibility of this process. The soluble-insoluble transition temperature for s-POSS-(PDMAEMA)16 was located between 20 and 60 °C. Furthermore, equilibrium adsorption indicated that s-POSS-(PDMAEMA)16 could adsorb Cr(VI) due to strong electrostatic interactions between its tertiary amines and Cr(VI).

Double-decker silsesquioxane (DDSQ) cages were introduced into the main chains of polycyclooctadiene via a ring-opening metathesis polymerization (ROMP) approach. Toward this end, a macromolecular ...

An efficient process for the synthesis of degradable hydrogels containing octa-betaine ester polyhedral oligomeric silsesquioxane (POSS) through efficient thiol-ene and Menschutkin click reactions was developed. The hydrogels exhibited a yield strength of 0.36 MPa and a compressive modulus of 4.38 MPa and displayed excellent flexibility as well as torsion resistance. Antibacterial efficacy of hydrogels (and degradation products) was evaluated using

We study the phase behavior of a triblock organic–inorganic hybrid copolymer, poly(polyhedral oligomeric silsesquioxane)-b-poly(ethylene oxide)-b-poly(polyhedral oligomeric silsesquioxane) (POSS-PE...

The chain dimension and dynamics of type-A polymer, poly(1, 2-butylene oxide) (PBO), in the nanocomposites comprising polyhedral oligomeric silsesquioxane (POSS) nanoparticles have been investigate...

Especially in orthopedics and implant applications, the bone cements are the main pillar of implants to form permanent bonds with the body. However, the main risk factor for implants is infection and loosening of the implant over time. This situation can seriously compromise patient comfort and even patient life. Therefore, superior mechanical strength, biocompatibility and antimicrobial properties are required for comfortable and healthy use. In this study, antibacterial bone cements synthesized as bone filler for application in orthopedic surgeries. Compositon was conducted by synthesing polymethyl methacrylate in the presence of curcumin, polyhedral oligomeric silsesquioxane (POSS), hydroxyapatite and free radical curable PEG functional quaternary polyethylenimine and were analyzed by using the methods of X-ray diffraction, Fourier Transform Infrared Spectroscopy, dynamic mechanical analysis and scanning electron microscopy. The inhibition zone areas and the surface activity resistances of the bone cement composites were analyzed against the bacteria Escherichia coli (E. coli), Listeria monositogenes (L. monositogenes), Salmonella and Staphylococcus aureus (S. aureus). Biocompatibility analysis was also applied via MTS assay. Analysis results confirm the suitable surface biocidal activity along with high cells viability of curcumin and pegylated quaternary polyethylene based bone cement, indicating its potentials for orthopedic applications.

The poly(lactic acid)(PLA)/aliphatic poly(carbonate)(PPC)/polyethylene glycol-polyhedral oligomeric silsesquioxane (PEG-POSS) composites were prepared by reactive melting extrusion. The effect of v...

The present work focuses on the phase evolution of SiZrOC ceramic hybrids derived from the doping of Zr in a phenyl-containing silsesquioxane based preceramic polymer in the temperature range of 800 °C–1300 °C. A commercially available polymethylphenylsilsesquioxane polymer was doped with 5–20 mol% of Zr (through alkoxide source), and cross-linked. Inert atmosphere pyrolysis of thus produced powders yielded black colored SiZrOC ceramics. It was revealed that the dopants phase separate into t-ZrO2 beyond 800 °C. The crystallite size of t-ZrO2 was calculated from the X-ray diffractograms using Scherrer formula. Raman spectroscopy was employed to study the effect of dopant ion on retention of carbon and silica residual phases in the final ceramic hybrid. The crystallites of ZrO2 were further analyzed by high resolution transmission electron microscopy. The characterizations of Zr doped SiOxCy ceramic hybrids exhibit potential for coating systems in moderate to high temperature applications.

Methacrylate-containing silsesquioxane–siloxane oligomers with Mw = (2–20) × 103 determined by gel permeation chromatography (GPC) are synthesized by acidohydrolytic copolycondensation of γ‑methacryloxypropyltrimethoxysilane and diorganodialkoxysilanes. According to the data of 29Si NMR spectro-scopy, the molecules of these oligomers contain silsesquioxane units (RSiO1.5)n, where R is a γ-methacryloxypropyl radical, and mixed cyclic structures of the (RSiO1.5)m(R'R''SiO)p type, where R' is CH3 and R'' is CH3 or C6H5, with linear diorganosiloxane fragments added to them. The introduction of 6 wt % silsesquioxane–siloxane oligomers into a filled base dental compound based on a mixture of bismethacrylates increases its mechanical characteristics by more than a factor of 1.25–1.75 with a simultaneous substantial decrease in the polymerization shrinkage, water uptake, and water solubility.

Polyhedral oligomeric silsesquioxane (POSS) was grafted onto the surface of carbon fibres (CFs) to fabricate carbon fibre/epoxy (CF/EP) composites with improved interlaminar shear strength (ILSS) and atomic oxygen (AO) erosion resistance. POSS-CF was prepared by reacting amine groups on the pretreated CF surface with the POSS to form a continuous uniform layer of siloxane oligomers. X-Ray photoelectron spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated that POSS was successfully grafted onto the CF surface. The ILSS and AO erosion resistance of the POSS-treated CFs and CF-EP interface were improved because a SiO2 passivation layer formed with AO exposure, especially with POSS-EP0409. This is an effective solution for enhancing the interfacial bonding force and interfacial AO erosion resistance for the low-Earth orbit environment.

Author(s): Gao, KW; Jiang, X; Hoffman, ZJ; Sethi, GK; Chakraborty, S; Villaluenga, I; Balsara, NP | Abstract: Poly(ethylene oxide)-b-polyhedral oligomeric silsesquioxane (PEO–POSS) mixed with lithium bis(trifluoromethanesulfonyl)imide salt is a nanostructured hybrid organic–inorganic block copolymer electrolyte that may enable lithium metal batteries. The synthesis and characteristics of three PEO–POSS block copolymer electrolytes which only differ by their POSS silica cage substituents (ethyl, isobutyl, and isooctyl) is reported. Changing the POSS monomer structure results in differences in both thermodynamics and ion transport. All three neat polymers exhibit lamellar morphologies. Adding salt results in the formation of a disordered window which closes and gives way to lamellae at higher salt concentrations. The width of disordered window decreases with increasing length of the POSS alkyl chain substituent from ethyl to isobutyl and is absent in the isooctyl sample. Rheological measurements demonstrate good mechanical rigidity when compared with similar all-organic block copolymers. While salt diffusion coefficient and current ratio are unaffected by substituent length, ionic conductivity increases as the length of the alkyl chain substituent decreases: the ethyl substituent is optimal for ion transport. This is surprising because conventional wisdom suggests that ion transport occurs primarily in the PEO-rich domains, that is, ion transport should be unaffected by substituent length after accounting for the minor change in conducting phase volume fraction. © 2020 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2020 © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 363–371.

In this study, a novel ionic silsesquioxane (Si4DMAP+Cl−) was developed through a facile synthetic sol–gel method and utilized as a recoating layer with the cobalt(II) tetrassulphophthalocyanine (CoTsPc) compound in order to modify a glassy carbon electrode (GCE) substrate. The silsesquioxane material was characterized using 29Si and 13C NMR, FTIR, TGA, fluorescence and UV-Vis spectroscopic techniques. Additionally, the GCE/CoTsPc–Si4DMAP+Cl− electrode platform was applied as an electrochemical sensor for the determination of nifedipine (NIF), an anti-hypertensive drug, and its main metabolite, dehydronifedipine (dHNIF). DFT calculations were also performed to evaluate the redox properties of NIF and dHNIF. Individual and simultaneous determinations of NIF and dHNIF were performed in the range of 0.015–1.75 μmol L−1 using optimized supporting electrolyte conditions and stripping differential pulse voltammetry as an analytical tool. The limit of detection (LoD) values for both analytes were 6.2 nmol L−1 for NIF and 4.5 nmol L−1 for dHNIF, respectively. The proposed method was applied for the determination of NIF and dHNIF in synthetic urine and serum samples with a recovery range between 101–110% (n = 3). The GCE/CoTsPc–Si4DMAP+Cl− electrode platform is presented here as a biomedical testing tool considering therapy-resistant conditions of hypertensive patients.