Polyhedral Oligomeric Silsesquioxane Methacrylate Research Articles

Processing and Characterization of UV Irradiated HDPE/POSS Fibers.

High-performance polyethylene fibers, renowned for their superior attributes encompassing a high strength, modulus, and lightness, are conventionally manufactured through the gel spinning method. However, this method is encumbered by several drawbacks, including the requisite application of a separate process to eliminate solvents from the fibers and the utilization of chemicals deleterious to both the environment and human health. Alternatively, the adoption of the melt spinning method presents a cleaner and environmentally friendly approach to attain high-performance fibers. In the present investigation, high-density polyethylene (HDPE) fibers were produced employing the melt spinning method. After the spinning process, strategic orientation procedures were implemented to enhance the crystallinity of the spun fibers. As a concluding step, seeking to elevate the overall performance of the oriented spun HDPE fibers, a cross-linking treatment was applied via UV irradiation. Notably, this study pioneers the incorporation of polyhedral oligomeric silsesquioxane (POSS) hybrid nanoparticles into HDPE during melt spinning, presenting a novel advancement aimed at further enhancing the mechanical properties of oriented HDPE fibers during UV irradiation. For this purpose, two distinct types of POSS, namely octavinyl POSS (OVPOSS) and methacryl POSS (MACPOSS), both having unsaturated double bonds capable of participating in the network structure of oriented HDPE spun during UV cross-linking, were used. The thermal, morphological, and mechanical properties, as well as the crystal structure of samples with and without POSS molecules, were investigated. The mechanical properties of the fibers exhibited higher values in the presence of OVPOSS. The incorporation of OVPOSS and MACPOSS resulted in a noteworthy improvement in the material's tensile strength, exhibiting a marked increase of 12.5 and 70.8%, respectively. This improvement can be attributed to the more homogeneous dispersion of OVPOSS in HDPE, actively participating in the three-dimensional network structure. After orientation and UV irradiation, the tensile strength of HDPE fibers incorporating OVPOSS increased to 293 MPa, accompanied by a concurrent increase in the modulus to 2.8 GPa. The addition of POSS nanoparticles thus yielded a substantial improvement in the overall performance of HDPE fibers.

Study of Water Sorption in Methacryl-Based Polyhedral Oligomeric Silsesquioxane (POSS) Dental Composites Using Molecular Dynamics Simulations.

Methacrylate-based polyhedral oligomeric silsesquioxane (POSS) is one of the new composites used as a dental resin. Both monofunctional methacryl isobutyl POSS (MIPOSS) and multifunctional methacryl POSS (MAPOSS) are reported to be possible resins that possess the desired properties for using them as dental resins. Our group's previous comparative study on these two resins showed that the MAPOSS composite has superior mechanical properties compared with the MIPOSS composite. In this article, molecular dynamic simulations (MD simulations) are performed to study the water sorption in these two composites. Water sorption in dental composites can have several effects on the material properties, performance, and longevity of dental restorations. Water sorption in MAPOSS and MIPOSS composites is analyzed by studying the hydrogen bonding, cluster analysis, density projection calculations, and diffusion coefficient calculation of water molecules within the resin matrix. MD simulations results are further used to understand the interaction of water molecules with the resin matrix comprehensively, which governs the composite's mechanical properties. The water sorption study showed that the MAPOSS composite has less water sorption capacity than the MIPOSS composite. The practical significance of this study is to find properties that affect dental restoration and longevity, which can help in the design of better materials for dental applications.

3D printed human hair - polymer continuous fiber reinforced composites through Vat Photopolymerization process

This study gives insight into the fabrication of 3D-printed human hair polymer composites using the Stereolithography (SLA) technique. Different surface modification techniques have been introduced to overcome the problem of poor interfacial adhesion between the fiber and the matrix. Human hair fibers were modified by grafting with Methacryl Polyhedral Oligomeric Silsesquioxane (MA-POSS) and cold air plasma treatment. The effect of the surface treatment was investigated using single hair pull-out tests, and the results showed that plasma-treated human hair composites showed the best performance in terms of interfacial strength between fibers and matrix. Furthermore, the mechanical properties of 3D-printed human hair composites have been investigated. The results indicate that the ultimate tensile strength has increased by 35% in plasma-treated composites compared to nontreated human hair composites and 100% compared to composites with no reinforcement. Scanning Electron Microscopy (SEM) and an optical microscope were used to study the surface morphology of the modified fibers. Moreover, X-ray Photoelectron Spectroscopy (XPS) was performed to confirm the grafting of MA-POSS on the human hair fibers. In addition, the X-ray Computed Tomography (µ-CT) technique has been utilized to analyze voids, fiber volume, and fiber orientation.

Molecular Simulations of Low-Shrinkage Dental Resins Containing Methacryl-Based Polyhedral Oligomeric Silsesquioxane (POSS)

Nanocomposites of methacrylate-based polyhedral oligomeric silsesquioxane (POSS) are used as resins in dentistry to fill dental cavities. In this article, molecular dynamics simulations (MDS) are used to study and understand the interactions of monofunctional and multifunctional methacrylate groups on hybrid resins containing POSS additives for dental applications. These interactions are further related to the structural properties of the nanocomposites, which in turn affect their macro-properties that are important, especially when used for specific uses such as dental resins. For monofunctional methacrylate, nanocomposite of methacryl isobutyl POSS (MIPOSS) and for multifunctional methacrylate, methacryl POSS (MAPOSS) are used in this study. Molecular dynamic simulations (MDS) are performed on both MIPOSS and MAPOSS systems by varying the amount of POSS. On a weight percent basis, 1%, 3%, 5%, and 10% POSS are added to the resin. Density calculations, stress-strain, and powder diffraction simulations are used to evaluate the macro-properties of these nanocomposites and compare them with the experimental findings reported in the literature. The observations from the simulation results when compared to the experimental results show that MDS can be efficiently used to design, analyze, and simulate new nanocomposites of POSS.

Highly Sensitive Photopolymer for Holographic Data Storage Containing Methacryl Polyhedral Oligomeric Silsesquioxane.

Herein, via introducing eight methacryl polyhedral oligomeric silsesquioxane (Ma-POSS), we dramatically enhance the holographic performance of phenanthraquinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer with excellent characteristics of high sensitivity, high diffraction efficiency, and neglectable volume shrinkage for holographic data storage, the photosensitivity, diffraction efficiency, and volume shrinkage reaching 1.47 cm/J, ∼75%, and ∼0.09%, respectively. Ma-POSS here dramatically enhances the photosensitivity ∼5.5 times, diffraction efficiency more than 50%, and suppressed the volume shrinkage over 4 times. Further analysis reveals that Ma-POSS obviously increased the molecular weight by grafting PMMA to be a star-shaped macromolecule. And the residual C=C of POSS–PMMA dramatically increased the photosensitivity. Moreover, the star-shaped POSS–PMMA acting as a plasticizer dramatically enhances the mechanical properties and so reduces the photoinduced volume shrinkage of PQ/PMMA. Finally, by the use of the POSS–PMMA/PQ in a collinear holography system, it appeared to be promising for a fast but low bit error rate in holographic information storage. The current study thence has not only successfully synthesized photopolymer materials with potential for highly sensitive holographic storage applications but also investigated the microphysical mechanism of the impact of Ma-POSS on the holographic properties of PQ/PMMA photopolymer and clarified the thermal- and photoreaction processes of the POSS–PMMA/PQ photopolymer.

Fabrication of monolithic capillary columns with inner diameter 50-530μm employing a mixture of pentaerythritol tetraacrylate and polyhedral oligomeric silsesquioxane-methacrylate as crosslinkers.

Highly crosslinked monolithic capillary columns with inner diameters in the range of 50-530μm were prepared by radical polymerization of pentaerythritol tetraacrylate, polyhedral oligomeric silsesquioxane-methacrylate, and n-octadecyl methacrylate in the presence of methanol, dodecyl alcohol, and polyethylene glycol lauryl ether. Columns were evaluated by inverse size-exclusion chromatography employing a set of polystyrene standards of narrow molecular-size distribution and by scanning electron microscopy. Chromatographic performance under reversed-phase conditions was also evaluated. The combination of two effective crosslinkers as pentaerythritol tetraacrylate and polyhedral oligomeric silsesquioxane-methacrylate in the polymerization mixture allows for the preparation of robust and efficient monolithic capillary columns within a fairly wide range of internal diameters.

Modified POSS nano-structures as novel co-initiator-crosslinker: Synthesis and characterization

ObjectiveTo synthesize an amine-modified polyhedral oligomeric silsesquioxane (POSS) nano-structure as a novel co-initiator-crosslinker (co-Ini-Linker) and to determine the effect of the co-Ini-linker on the physical and mechanical behavior of an experimental dental composite. MethodsThe amine-methacrylate POSS nano-structures (AMA-POSS) were chemically synthesized by anchoring a tertiary amine functionality on the methacrylate POSS (MA-POSS) branches. Three types of AMA-POSS, having different amine branches in their structures, were synthesized through the Aza Michael reaction. The chemical structure of AMA-POSSs were evaluated by1H-NMR spectroscopy. Afterward, the AMA-POSS was incorporated into a dental resin system composed of Bis-GMA, TEGDMA, and photo-initiator. Three resin systems with different AMA-POSS types were then prepared, and their properties were compared with a resin containing DMAEMA as a conventional co-initiator. The degree of conversion evaluated by FTIR spectroscopy and the shrinkage kinetics of the resins were determined through the bonded-disk technique. The flexural properties of the photopolymerized resins were also investigated. The distribution of nano-structures in the matrix resin was analyzed using EDX analysis. ResultsThe modified POSS structure and the number of amine branches were confirmed with1H-NMR spectroscopy. The resin containing 8 amine branches (P8) showed the same degree of conversion (DC%) as the resin containing DMAEMA (P > 0.05). Decreasing the amine branches in the POSS structure, however, revealed an increasing trend in DC%. The resin containing P8 showed the lowest shrinkage strain. By incorporating AMA-POSS into the resin system, the water sorption significantly decreased (P < 0.05). The flexural strength and modulus increased by adding P3 into the resin system (P < 0.05). EDX Si-map revealed that the co-Ini-linker was well dispersed in the resin matrix. SignificanceThe synthesized novel amine-methacrylate POSS nanostructures not only act as an amine co-initiator but also work as a reinforcing filler and a cross-linking agent.

Improving the Physical-Mechanical Property of Dental Composites by Grafting Methacrylate-Polyhedral Oligomeric Silsesquioxane onto a Filler Surface.

Endowing dental composites with excellent interfacial bonding through filler surface modification is pivotal to improve the physical-mechanical property and prolong the life of composite fillings. In this study, methacrylate-polyhedral oligomeric silsesquioxane (MA-POSS) acts as a "molecular bridge" between the commonly used SiO2 particles and the methacrylate-based resin matrix via a thiol-ene click reaction to construct MA-POSS/SiO2 (p-SiO2) hybrid particles. Synthesized p-SiO2 exhibited the roughest surface morphology and had more polymerizable groups, in comparison with SiO2 and silanized SiO2. Furthermore, the p-SiO2 particles were used as a reinforcement to fabricate bisphenol A glycerolate dimethacrylate/tri(ethyleneglycol) dimethacrylate-based dental composites, where the SiO2- and silanized SiO2-filled composites served as the control groups, and the filler loading was fixed at 65 wt %. Results of the mechanical properties indicated that the hybrid p-SiO2 particles significantly improved the flexural strength, flexural modulus, compressive strength, and work of fracture of dental composites, giving improvements of 251.2, 17.89, 122.3, and 1094%, respectively, over the SiO2-filled composites due to the strong interfacial interaction between the resin matrix and p-SiO2. Additionally, this optimal p-SiO2-loaded composite also presented better polymerization shrinkage, acceptable degree of conversion, curing depth, and cell viability. Grafting of MA-POSS onto a filler surface is a promising filler surface modification to improve the resin matrix/filler interfacial interaction, leading to the enhanced overall performance of composites.

Ionic Liquid 1-Vinyl-3-dodecylimidazole Bromide Embedded Hybrid Monolithic Column and Its Versatile Post-modification with Amino Acids

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.

Characterization of Methacrylate-Based Resins Containing Methacryl-Polyhedral Oligomeric Silsesquioxanes (MA-POSS-8).

The use of functionalized dental adhesives that might prevent degradation of the dentin hybrid layer has been proposed. The aim of the study was to characterize the physicochemical properties and the potential to induce mineral precipitation of methacrylate-based resins containing methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS-8). In total, six different compositions of resins based on bisphenol A glycerolate dimethacrylate (BisGMA, 40 to 60 wt.%), triethylene glycol dimethacrylate (TEGDMA, 5 to 35 wt.%) and 2-hydroxyethyl methacrylate (HEMA, 25 or 35 wt.%) were prepared and infiltrated with 5 wt.% MA-POSS-8. Unfilled resins served as control. Degree of conversion, viscosity, Martens hardness, indentation modulus, water sorption, and sol fraction were investigated. Polymerized specimens were examined by SEM/EDX for the presence of Ca/P precipitates after immersion in artificial saliva for 28 days at 37 °C. Statistical analysis was performed with two-way ANOVA and Tukey’s post-hoc test (p < 0.05). The degree of conversion ranged from 55.0 to 59.8% and was not affected by the addition of MA-POSS-8. Viscosity ranged from 60.0 to 422.3 mPa*s and was not affected by MA-POSS-8 except for one methacrylate-based resin with 60 wt.% BisGMA. Martens hardness and indentation modulus ranged from 161.3 to 138.1 N/mm2 and 4.2 to 3.9 kN/mm2 and were affected by MA-POSS-8 in only one resin (50 wt.% BisGMA, 25 wt.% TEGDMA, 25 wt.% HEMA). Water sorption was not affected by MA-POSS-8; sol fraction was below the detection limit. Formation of Ca/P precipitates was observed on all specimens of test and control groups. Material properties were not affected adversly by MA-POSS-8 except for slight differences in Martens Hardness, indentation modulus, viscosity, in some groups.

Synthesis of Hybrid Polymer Modifier (HPM) Nanomaterials with Improved Dispersion in Epoxy Resins

Epoxy resins exhibit good thermal stability, excellent chemical resistance, and enhanced modulus. Despite the favorable properties of epoxy resins, their high crosslink density causes them to be inherently brittle. Recent studies have focused on the potential of carbon-based nanomaterials such as GO to address these issues in epoxies. However, the presence of oxygen within these functional groups could degrade GO thermo-oxidatively and result in the loss of valuable properties of pristine graphene. Past research has reported the successful grafting of GO with suitable molecules like POSS to optimize thermal stability. In this work, a hybrid polymer modifier (HPM) has been developed by grafting Methacryl Polyhedral Oligomeric Silsesquioxanes (MAPOSS) to GO via a redox reaction. HPM was characterized using Fourier Transform Infrared (FTIR), Raman analysis, X-ray diffraction (XRD), X-ray fluorescence (XRF) spectroscopy, Thermogravimetric Analysis (TGA), and Transmission Electron Microscopy (TEM). XRF analysis showed that 10.2 mass% of silicon was added to GO due to the MAPOSS grafting. Furthermore, Raman analysis confirmed the increased structural distortion of GO induced by the incorporation of MAPOSS ((ID/IG) HPM= 1.43, (ID/IG) GO = 1.30). The dispersion of HPM was studied using optical microscopy in Epoxy.

A novel luminescence sensor based on porous molecularly imprinted polymer-ZnS quantum dots for selective recognition of paclitaxel

In this study, a molecularly imprinted fluorescent sensor was constructed successfully for selective recognition of PTX by introducing methacryl polyhedral oligomeric silsesquioxane (M-POSS) to add porous structure. The obtained fluorescent sensors were prepared by grafting MIP shell on the surface of silane functionalized Mn: ZnS Quantum Dots (QDs) by a free radical polymerization process. The binding properties and selectivity of the MIP-QDs were demonstrated by adsorption capacity obtained based on fluorescence spectroscopy. These MIP-based fluorescent sensors showed good dispersibility and high stability in solution. Under the optimized conditions, the binding experiment demonstrated the fluorescent intensity of the porous fluorescent sensors was obviously decreased with the increase of PTX in the concentration range 0.1–2.0 μM and the detection limit was 0.043 μM. These results demonstrated a new type of molecularly imprinted fluorescent porous nanoparticles with potential applications for selective recognition of PTX biological samples.

Pd on magnetic hybrid of halloysite and POSS‐containing copolymer: An efficient catalyst for dye reduction

A novel catalytic nanocomposite, MNPs/Hal‐POSS‐HEMA‐Pd, composed of halloysite nanoclay and polyhedral oligomeric silsesquioxane is reported. To synthesize the catalyst, magnetic halloysite was vinyl functionalized and then polymerized with 2‐hydroxyethyl methacrylate and methacrylate polyhedral oligomeric silsesquioxane. Afterwards, the latter was palladated to furnish a heterogeneous catalyst with use for catalyzing the reductive degradation of organic dyes, Rhodamine B, and methyl orange with NaBH4. The kinetic and thermodynamic parameters of both reactions were estimated. The results asserted that low content of the catalyst could catalyze the dye reduction reactions to furnish hydrogenated product in quantitative conversion in a very short reaction times (1 min). It is assumed that both halloysite and polyhedral oligomeric silsesquioxane can contribute to the anchoring of Pd nanoparticles. On the other hand, the polymeric network around halloysite can furnish a microenvironment for bringing dyes in the vicinity of active sites. Moreover, unique tubular morphology of halloysite can effectively improve dye adsorption and consequently enhance dye reduction. Additionally, the study of the recyclability of the catalyst approved that it could be magnetically recovered and reused for ten successive reaction runs with trivial leach of Pd (2 wt.%) and decrement of the catalytic activity.

Effect of different molecular architectured POSS-fluoropolymers on their self-assembled hydrophobic coatings

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.

Echinops bannaticus plant and Zinnia grandiflora extract as char biosource and reducing agent for the biosynthesis of Ag on magnetic char‐polymer: An efficient catalyst for water treatment

In attempt to expand the use of natural compounds for waste treatment, a novel catalyst with the utility for dye reductive degradation is reported. In the catalyst synthesis procedure, the plant Echinops bannaticus was applied as a biosource and hydrothermally treated to furnish a hydrochar that served as a support. The latter was magnetized, vinyl functionalized, and then polymerized with copolymer of 2‐hydroxyethyl methacrylate and methacrylate polyhedral oligomeric silsesquioxane. Subsequently, Ag nanoparticles were stabilized on the resultant composite with the aid of Zinnia grandiflora extract as a natural reducing agent. The resulting catalyst displayed high catalytic activity for the reduction of methylene orange and rhodamine B dyes in aqueous media at room temperature. The effects of the reaction variables, including the reaction time and temperature, and the catalyst loading, were examined and the kinetic and thermodynamic terms for both reactions were evaluated. Ea, ΔH#, and ΔS# values for the reduction of methyl orange were estimated as 50.0 kJ/mol, 51.50 kJ/mol, and −102.42 J mol−1 K−1, respectively. These values for rhodamine B were measured as 28.0 kJ/mol, 25.5 kJ/mol, and −187.56 J mol−1 K−1, respectively. The recyclability test also affirmed that the catalyst was recyclable for several runs with insignificant Ag leaching and decrement of its activity.

Phase Behavior of Carbon Dioxide and Polyhedral Oligomeric Silsesquioxanes with Two Different Functional Groups

Phase behavior of carbon dioxide and polyhedral oligomeric silsesquioxanes (POSS) modified with two different functional groups is studied in the temperature range of 308-323 K, up to 22 MPa. Different than the common types, one of the eight functional groups attached to the Si atoms of these POSS is a CO2-philic functional group, methacryl, while the rest are branched alkyl chains, either isooctyl (MIOPOSS) or isobutyl (MIBPOSS). Methacrylisobutyl POSS-CO2 binary system exhibits pressure-induced melting temperature depression. Both molecules have higher solubilities in scCO2 compared to their counterparts with single type of functionality, octaisobutyl POSS, isooctyl POSS and methacryl POSS. The measured highest solubility of MIBPOSS is 0.006 mole fraction at 323 K and 16.8 MPa, while it is 0.0017 mole fraction at 323 K and 22.1 MPa for MIOPOSS. Various density-based semi-empirical models used to model the solubility data gave good correlations with AARD of about 4%.

Study of POSS on the Properties of Novel Inorganic Dental Composite Resin.

Various amounts of methacryl polyhedral oligomeric silsesquioxane (POSS) were explored to be incorporated into novel nano SiO2 dental resin composites using light curing method. The scanning electron microscopy (SEM), optical microscopy, fourier transform infrared spectroscopy (FTIR), nanoindentation, nanoscratch and three-point flexure tests were performed. The volumetric shrinkage and mechanical properties such as hardness, elastic modulus, resistance, flexural strength and fracture energy were analyzed. With the additions of POSS, the volume shrinkage decreased and the mechanical properties initially increased. The effects of POSS on these properties were studied to provide a reference for clinically selecting a composite resin with excellent properties.

Mineral precipitation, polymerization properties and bonding performance of universal dental adhesives doped with polyhedral oligomeric silsesquioxanes

ObjectivesTo investigate the effect of methacrylate polyhedral oligomeric silsesquioxane (POSS-8) particles on the polymerization process, dentin bond strength, and mineral precipitation of universal dental adhesives. MethodsFive universal adhesives (Adhese Universal, CLEARFIL Universal Bond, Futurabond U, iBOND Universal, Scotchbond Universal) were filled with POSS-8 particles (10 wt%, additionally 2 wt% and 5 wt% in Scotchbond Universal). The particle size and dispersion in ethanol and acetone were examined by dynamic light scattering. Degree of conversion, linear shrinkage, and shear bond strength to dentin treated with the filled and pure adhesives (controls) were measured. Growth of calcium phosphate (Ca/P) precipitates on the adhesive specimens immersed in artificial saliva for up to 28 days was analyzed by energy-dispersive X-ray spectroscopy and scanning electron microscopy. Statistical analyses were performed using ANOVA and Tukey's post-hoc tests (p < 0.05). ResultsThe hydrodynamic radius of the particles in acetone (1.4 ± 0.4 nm) and ethanol (1.1 ± 0.4 nm) revealed their good dispersion. POSS-8 did not change the degree of conversion and dentin bond strength of any adhesive. Ca/P precipitates formed on iBOND Universal specimens doped with POSS-8 after 4 weeks of immersion, but were not detected on the unfilled adhesive. The mineral precipitation of all other adhesives was not improved by POSS-8. SignificancePOSS-8 particles did not compromise polymerization and bonding of universal adhesives. Ca/P precipitation was stimulated by POSS-8 only in iBOND Universal.

Synthesis and characterization of molecularly imprinted polymer microspheres functionalized with POSS

A type of novel porous molecularly imprinted polymer (MIP) microspheres containing methacryl polyhedral oligomeric silsesquioxane (M−POSS) were synthesized through reversible addition-fragmentation chain transfer polymerization precipitation polymerization (RAFTPP). The obtained porous microspheres had narrow particle size distribution and regular spherical shape. The addition of M−POSS could not only largely enhance the structural stability but also increase the pore structure of MIPs. The composition and shape characteristic of the MIPs were characterized by FT-IR, CA, SEM, TGA, and N2 adsorption–desorption isotherm. The binding properties and selectivity of the MIP and non-imprinted polymer (NIP) were demonstrated by adsorption capacity obtained based on HPLC absorption measurements. The results showed that the adsorption capacity of the paclitaxel imprinted polymer containing 85 mg M−POSS (PTX-MIP2) for PTX reached 17.24 mg g−1 after 200 min. A comparative study demonstrated that PTX-MIP2 possessed excellent selectivity towards PTX, which presented an imprinting factor of 3.17. Meanwhile, PTX-MIP2 could be reused five cycles with slight loss in adsorption capacity.

Synthesis of a poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) hybrid monolith via an in-situ ring opening quaternization for use in hydrophilic interaction capillary liquid chromatography.

An in-situ approach is described for synthesis of poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) [poly(sulfobetaine-co-POSS)] that can be used in a hybrid monolithic column as a hydrophilic liquid chromatography (HILIC) stationary phase. Synthesis involves (a) radical polymerization of octa(propyl methacrylate)-polyhedral oligomeric silsesquioxane (MA-POSS) and organic monomers such as dimethylaminopropyl methacrylate or vinyl imidazole, and (b) in-situ ring-opening quaternization between 1,4-butane sultone and the organic monomers. The sulfobetaine groups are generated in-situ monolith. This obviates the need for synthesis of sulfobetaine monomer previously. The pore size and permeability of the material can be tuned by using a binary porogenic system (polyethyleneglycol 600 and acetonitrile) and via the composition of the polymerization mixture. The optimized hybrid monolith owns its merits to the presence of POSS and sulfobetaine groups with good mechanical stability, the lack of residual silanol groups, and adequate hydrophilicity. The column filled with the monoliths was evaluated as a stationary phase for HILIC. Several kinds of polar compounds (including nucleosides, bases, phenols, aromatic acids and amides) were separated by using mobile phases with high organic solvent fractions in capillary liquid chromatography. Graphical abstractAn in-situ approach is described for synthesis of poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) hybrid monolithic column for use in hydrophilic liquid chromatography. The optimized monolith owns good mechanical stability, the lack of residual silanol groups and adequate hydrophilicity. Baseline separation of several kinds of polar compounds is achieved on the column. MA-POSS: octa(propyl-methacrylate) polyhedral oligomeric silsesquioxane; DMAEMA: dimethylaminoethyl methacrylate; AIBN: azodiisobutyronitrile. Poly(DMABS-co-POSS): poly(N-(4-sulfobutyl)-N-methacryloxypropyl- N,N-dimethylammonium-betaine-co-polyhedral oligomeric silsesquioxane).