Oligomeric Silsesquioxane Hybrid Research Articles

Structure–property relationships and nanofiller‐induced hydro‐anti‐plasticization in polyhydroxyurethane/POSS hybrid composites

AbstractNon‐isocyanate polyhydroxyurethanes/polyhedral oligomeric silsesquioxane (PHU/POSS) hybrid composites are prepared by in situ physical introduction of octa(3‐hydroxy‐3‐ethylbutyldimethylsiloxy) POSS into a linear non‐isocyanate polyhydroxyurethane matrix. The amorphous nature of the matrix is retained in the composites and no POSS crystals are observed. Thermal and mechanical properties are studied along with water‐polymer interactions and are discussed in terms of structure‐properties relationships. POSS has only minimal effect on thermal stability. Composite materials with up to 2 wt% POSS exhibit an increased rubbery modulus. The glass transition temperature of the composite materials increases up to 2 wt% loading and decreases at higher POSS content. Water‐polymer interactions are studied in a broad range of relative humidity (0–0.97). Materials exhibit a relatively high water absorption, which is enhanced by POSS at low concentrations. Moisture sorption isotherms are discussed in terms of the Guggenheim‐Anderson‐de Boer model. The study of molecular mobility of hydrated systems by differential scanning calorimetry reveals a peculiar POSS‐induced antiplasticization in PHU/POSS blends at 10–20 wt% water uptake, possibly due to the formation of POSS‐centered water clusters.

Examining the Water-Polymer Interactions in Non-Isocyanate Polyurethane/Polyhedral Oligomeric Silsesquioxane Hybrid Hydrogels.

Non-isocyanate polyurethane (NIPU) networks physically modified with octa(3-hydroxy-3-methylbutyldimethylsiloxy)POSS (8OHPOSS, 0-10 wt%) were conditioned in environments of different relative humidities (up to 97%) to study water-polymer interactions. The equilibrium sorption isotherms are of Brunauer type III in a water activity range of 0-0.97 and are discussed in terms of the Guggenheim (GAB) sorption model. The study shows that the introduction of 8OHPOSS, even in a large amount (10 wt%), does not hinder the water affinity of the NIPU network despite the hydrophobic nature of POSS; this is attributable to the homogenous dispersion of POSS in the polymer matrix. The shift in the urethane-derived carbonyl bands toward lower wavenumbers with a simultaneous shift in the urethane N-H bending bands toward higher wavenumbers exposes the breakage of polymer-polymer hydrogen bonds upon water uptake due to the formation of stronger water-polymer hydrogen bonds. Upon water absorption, a notable decrease in the glass transition temperature (Tg) is observed for all studied materials. The progressive reduction in Tg with water uptake is driven by plasticization and slaving mechanisms. POSS moieties are thought to impact slaving indirectly by slightly affecting water uptake at very high hydration levels.

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.

Promising Materials in the Fight against Healthcare-Associated Infections: Antibacterial Properties of Chitosan-Polyhedral Oligomeric Silsesquioxanes Hybrid Hydrogels.

New technologies and materials could help in this fight against healthcare-associated infections. As the majority of these infections are caused by antibiotic-resistant bacteria, the development of materials with intrinsic antibacterial properties is a promising field of research. We combined chitosan (CS), with antibacterial properties, with polyhedral oligomeric silsesquioxanes (POSS), a biocompatible polymer with physico-chemical, mechanical, and rheological properties, creating a hydrogel using cross-linking agent genipin. The antibacterial properties of CS and CS-POSS hydrogels were investigated against nosocomial Gram-positive and Gram-negative bacteria both in terms of membrane damage and surface charge variations, and finally, the anti-biofilm property was studied through confocal microscopy. Both materials showed a good antibacterial capacity against all analyzed strains, both in suspension, with % decreases between 36.36 and 73.58 for CS and 29.86 and 66.04 for CS-POSS, and in plates with % decreases between 55.29 and 78.32 and 17.00 and 53.99 for CS and CS-POSS, respectively. The treated strains compared to the baseline condition showed an important membrane damage, which also determined a variation of surface charges, and finally, for both hydrogels, a remarkable anti-biofilm property was highlighted. Our findings showed a possible future use of these biocompatible materials in the manufacture of medical and surgical devices with intrinsic antibacterial and anti-biofilm properties.

Preparation and application of sulfated lily polysaccharide bridged polyhedral oligomeric silsesquioxane hybrid organosilicas as stationary phase

Periodic mesoporous organosilicas (PMO) hydrophilic microspheres were synthesized by co-condensation of sulfated polysaccharide from Lilum lancifolium Thunb. bridged silane (SLLTPBS) and polyhedral oligomeric silsesquioxane (POSS) as stationary phase (PMO(SLLTP-POSS)) for per aqueous liquid chromatography (PALC), which would overcome the disadvantages of using a large amount of acetonitrile on the hydrophilic interaction liquid chromatography (HILIC) columns. Average particle size of PMO (SLLTP-POSS) microspheres was 4.9 μm, which was suitable for stationary phase. The retention mechanism of the stationary phase in PALC was mainly hydrophobic interactions and also included some ion-exchange interactions and electrostatic interactions. The acid-base resistance was greatly improved compared to the C18 column. The PMO(SLLTP-POSS) column under PALC mode had increased the resolution when separating some hydrophilic compounds such as eight organic acids and eleven sweeteners compared with the C18 column and HILIC column. The new column was more efficient than the HILIC columns. Additionally, a PALC-triple quadrupole mass spectrometry approach for the simultaneous identification of the eleven sweeteners was developed. The averagere coveries of the eleven compounds were 70.20%–91.33% with the relative standard deviation (RSD) range of 1.74% to 4.27%. The results showed good precision and accuracy of the method.

Covalent lindqvist polyoxometalate-cubic polyhedral oligomeric silsesquioxane hybrid material: enhancing photocatalytic antibacterial activity and hydrogen production as a heterogeneous catalyst

Covalent POM–POSS hybrid material was found to be excellent in photocatalytic antibacterial activity against E. coli owing to the generation of hydroxyl radicals and showed improved hydrogen generation due to the synergistic effect of POM and POSS.

Polyhedral Oligomeric Silsesquioxane as a Polarity Mediator and Reinforced Nanofiller for Fabricating Robust and Hierarchical Porous Film for Cell Bioengineering

A hierarchical porous polymer film that can provide a balance of mechanical properties and specific surface areas and sustain cell functions has become a major target for material scientists and bioengineers in the past decade. However, the limited availability of materials that exhibit high mechanical performance and easily form hierarchical porous structures hinder the progress in practical application. Here, we show the design of a polyhedral oligomeric silsesquioxane (POSS) hybrid polymer by incorporating a bi-functional glycidyl-propyl POSS (G-POSS) into the epoxy polymer backbone, in which POSS functions as both a nanofiller to reinforce the mechanical performance and as the polarity mediator to induce self-assembly of the polymer chains into a three-dimensional (3D) connected porous structure. Nanoindentation shows that the incorporation of POSS leads to a 25 and 36% increase in modulus and hardness, respectively. Scanning electron microscopy results show that POSS helps tune the hydrophobicity of the polymer and assists in the interface assembly, allowing easy formation of a densely packed two-dimensional or 3D hierarchical porous structure. Culture of mouse embryonic fibroblast cells demonstrates that the hybrid polymer scaffold provides prominent advantages ranging from enhanced cell adhesion to proliferation. Particularly, the 3D hierarchical porous film allows good nutrient supply and cell communication, which better mimics the in vivo microenvironment with less cell morphology change during cell proliferation. Hence, the successful integration of high material strength and easy formation of an interconnected porous structure shows that POSS hybrid polymers have strong potential for applications in the fabrication of cell culture platforms and future translation in tissue repair and regeneration.

Polyhedral Oligomeric Silsesquioxane Encountering Tannic Acid: A Mild and Efficient Strategy for Interface Modification on Carbon Fiber Composites.

Designing and controlling the interfacial chemistry and microstructure of the carbon fiber is an important step in the surface modification and preparation of high-performance composites. To address this issue, a tannic acid (TA)/polyhedral oligomeric silsesquioxane (POSS) hybrid microstructure, similar to the topological structure, is designed on the fiber surface by one-pot synthesis under mild conditions. Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) show that the functionality and surface roughness of the fiber are significantly broadened. Correspondingly, the tensile strength (TS) of CF-TA/POSS100 and interlaminar shear strength (ILSS) of CF-TA/POSS100-based composites increased by 18 and 34%, respectively. Following that, a failure mechanism study is conducted to demonstrate the interphase structure containing TA/POSS, which is quite critical in optimizing the mechanical performance of the multiscale composites. Moreover, the strategy for the use of TA for constructing a robust coating to replace the traditional modification without affecting the fiber intrinsic strength is an improved design and provides a new idea for the development of high-performance composites.

Chemically crosslinked polyimide-POSS hybrid: A dielectric material with improved dimensional stability and dielectric properties

One kind of the leading polymers applied in microelectronic packaging is polyimide (PI)-tethered polyhedral oligomeric silsesquioxane (POSS) hybrids. However, a well-known problem is that PI-POSS hybrids usually suffer from the serious thermal expansion at elevated temperature, leading to deteriorated reliability in electronic devices. In this work, a series of PI-POSS hybrids is successfully fabricated using aminopropylisobutyl-POSS as a reactive filler, and then the phenolic hydroxyl groups on side chains of hybrids react with terephthaloyl chloride at room temperature to form a crosslinked network. The well-designed crosslinked network suppresses the thermal expansion and improves the dielectric properties of hybrids together with POSS. As an example, after 24 h of crosslinking reaction, the coefficient of thermal expansion of the crosslinked hybrid with 14.6 wt% POSS (CPIH-2-24H) is 24 ppm/K, revealing a 59% reduction against the unmodified PI (82 ppm/K). Meanwhile, the dielectric constant and loss of CPIH-2-24H are decreased by ∼27% (2.68 vs. 3.68) and ∼72% (0.007 vs. 0.025), respectively, compared with the corresponding values for the unmodified PI. These data indicate that the resultant crosslinked PI-POSS hybrids may be used as microelectronic packaging materials, and the work provides a feasible approach to restrict the thermal expansion of PI-POSS hybrids by room-temperature chemical crosslinking.

Progress in the self-assembly of organic/inorganic polyhedral oligomeric silsesquioxane (POSS) hybrids.

This Review describes recent progress in the self-assembly of organic/inorganic POSS hybrids derived from mono-, di-, and multi-functionalized POSS cages. We highlight the self-assembled structures and physical properties of giant surfactants and chain-end- and side-chain-type hybrids derived from mono-functionalized POSS cages; main-chain-type hybrids derived from di-functionalized POSS cages; and star-shaped hybrids derived from multi-functionalized POSS cages; with various polymeric attachments, including polystyrene, poly(methyl methacrylate), phenolic, PVPh, and polypeptides.

Engineered partially open-cage fluorinated polyhedral oligomeric silsesquioxane hybrid nanoparticle aggregates for surfaces with super-repellency to widespread liquids

Co-polycondensation generates easy-to-use partially open-cage fluorinated polyhedral oligomeric silsesquioxane-nanoparticle (poc-FPOSS-NP) hybrid aggregates for surfaces with super-repellency to widespread liquids.

Ultrastable porous organic/inorganic polymers based on polyhedral oligomeric silsesquioxane (POSS) hybrids exhibiting high performance for thermal property and energy storage

In our work, we have been synthesized two-hybrid porous organic-inorganic microporous polymers (POIPs) through a simple and friendly Heck coupling reaction at a moderate temperature of cubic octavinylsilsesquioxane (OVS) with brominated fluorene (F–Br 2 ) and anthraquinone (A-Br 2 ); respectively, to afford POSS-F-POIP and POSS-A-POIP. FTIR, solid-state 13 C, and 29 Si NMR spectroscopy analyses were carried out to confirm the chemical structures of these POIP materials and the presence of POSS units within their framework. TGA measurements revealed that POSS-A-POIP possesses high thermal stability ( T d10 : 600 °C, and char yield: 83 wt%) due to the presence of rigid anthraquinone and POSS units. Furthermore, POSS-A-POIP features pseudocapacitor with high symmetry and high specific capacitance of 152.5 F g −1 at 0.5 A g −1 when compared with the POSS-F-POIP (36.2 F g −1 at 0.5 A g −1 ). The excellent energy storage performance of POSS-A-POIP could be attributed to the Faradaic reaction of anthraquinone and the π-conjugated system. • Two POSS-F-POIP and POSS-A-POIP were prepared through Heck coupling reaction. • The POSS-A-POIP possesses high thermal stability (T d10 : 600 °C, and char yield: 83 wt%). • The POSS-A-POIP features pseudocapacitor with high symmetry and high specific capacitance of 152.5 F g −1 at 0.5 A g −1 .

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.

Novel Flyweight Three-Dimensional Self-Assembled Graphene Oxide/Octa(Aminophenyl) Polyhedral Oligomeric Silsesquioxane Hybrid Aerogels

Herein, flyweight organic-inorganic hybrid scaffolds were fabricated by self-assembly and reduction of graphene oxide via covalent reaction of octa(aminophenyl) polyhedral oligomeric silsesquioxane with graphene oxide. Octa(aminophenyl) polyhedral oligomeric silsesquioxane created a decorative coating on the graphene oxide surface. It acts as a nano-crosslinker, especially on the overlapped-zone of graphene oxide platelets to bind them close-fitting. The resulting hybrid hydrogel was transformed into aerogel by the solvent exchange process with liquid carbon dioxide, followed by liquid carbon dioxide supercritical drying. Different concentrations of graphene oxide and octa(aminophenyl) polyhedral oligomeric silsesquioxane were prepared and the structure-property relationship of obtained aerogels is elucidated. The bulk density and porosity of the aerogels are located between the super-low values of 2.7 to 5.9 mg cm-3 and beyond 99.5 %, respectively. According to the adsorption-desorption isotherms of BET-technique, the surface area of obtained aerogels was between 250 to 713 m2/g. The findings remark the potential application of obtained aerogels in the production of supercapacitors, lithium-ion batteries, solar cells, etc. in energy storage and conversion devices, electrode materials, sensors, gas/oil/dye adsorbents, and high-temperature insulators in the aerospace industry.

Engineered bio-adhesive polyhedral oligomeric silsesquioxane hybrid nanoformulation of amphotericin B for prolonged therapy of fungal keratitis

• BPEP could effectively internalize poorly lipid soluble AMB. • BPEP possess good bio-adhesiveness, and improves ocular delivery of AMB. • BPEP significantly prolonged drugs retention time on the ocular surface. • BPEP-AMB inhibited fungal keratitis with a better efficiency than currently available drugs. Even though fungal keratitis is a severe corneal disease that can lead to permanent vision loss, its therapeutic management is still problematic. This limitation is in part attributable to the fact that tear film renewal curtails exposure time of drug containing eye drops to the ocular surface. Accordingly, anti-microbial therapy needs to be performed repeatedly. Efforts to resolve this hindrance include developing formulations that prolong drug retention on the ocular surface which can in turn improve therapeutic efficacy as well as reduce administration frequency. To extend drug residence time on the ocular surface, we designed a novel organic-inorganic hybrid consisting of a PEG-PPG copolymer modified with polyhedral oligomeric silsesquioxane (POSS) groups. Its tailored POSS-micelles possess both good biocompatibility and bio-adhesiveness, which improve ocular delivery of poorly soluble drugs. We describe here use of mouse fungal keratitis model to determine the effects of this formulation encapsulating amphotericin B (AMB) on this condition. The results show that POSS-micelles significantly prolonged AMB retention time on the ocular surface, leading to improved resolution of this disease. Moreover, this treatment strategy had no toxic effects during ocular administration either in vitro or in vivo. Therefore, this POSS formulation bearing AMB has the potential to prolong drug retention time and improve its therapeutic efficacy in managing fungal keratitis.

Facile preparation of thioether/hydroxyl functionalized polyhedral oligomeric silsesquioxanes hybrid polymer for ultrahigh selective adsorption of silver(I) ions

It is a difficult task to remove Ag(I) ions selectively from the complex wastewater containing low concentration of silver(I) ions and high concentration of interfering ions. In this work, the polyhedral oligomeric silsesquioxanes (POSS) hybrid polymer (PSDT) functionalized with thioether/hydroxyl groups was facilely synthesized by photo-initiated thiol-ene polymerization of vinylPOSS and 1, 4-dithiothreitol. The PSDT showed ultrahigh selectivity to Ag(I) ions in a wide pH range, which could completely remove trace level of Ag(I) ions (1 mg L−1) from the complex wastewater containing concentrated interfering ions such as Pb(II), Cu(II), Ni(II), Zn(II), Ca(II) and Fe(III) ions (each 200 mg L−1), nevertheless, those interfering ions were hardly adsorbed on the PSDT polymer. Moreover, the maximum adsorption capacity for Ag(I) by PSDT was 303 mg g−1 at pH 0.5, and the distribution coefficient (Kd) for Ag(I) ions could reach 1,620,000 mL g−1, which was significantly greater than most of the adsorbent materials reported. The high sulfur content (5.93 mmol g−1) of nanostructured PSDT and the formation of a stable five-membered Ag(I)-chelated ring may be the major causes for the ultrahigh selective adsorption of Ag(I) ions by PSDT.

A superhydrophobic covalent zeolitic imidazolate framework-polyhedral oligomeric silsesquioxane hybrid material as a highly efficient and reusable sorbent for organic solvents

A robust, fluorine-free, superhydrophobic ZIF-POSS hybrid material is prepared by a post-covalent reaction between ZIF-90 and POSS-NH2 via imine bond formation. The ZIF-POSS material is highly effective and reusable sorbent for organic solvents.

Construction and photoluminescence properties of octaimidazolium-based polyhedral oligomeric silsesquioxanes hybrids through the ‘bridge’ of ionic liquids: Chemical sensing for Cu2+

Herein, we demonstrate a successful preparation method of ionic liquid functionalized POSS hybrids by quaternization of imidazole salt with Octa-(ɤ-chloropropyl) POSS. A novel photofunctional hybrid soft material POSS- min-[Eu(tta)4] (tta:2-thenoyltrifluoroacetone) was reported via an ion-exchange reaction between imidazolium-based POSS(POSS-min-Cl) and lanthanide complex [Eu(tta)4]-. The obtained hybrids were extensively characterized by FT-IR, 1HNMR, 13CNMR, UV–Vis, PL and TGA in detail. What's more, POSS-min-[Eu(tta)4] displays higher fluorescence intensity, longer lifetime and higher thermostability than corresponding pure complex. More significantly, POSS-min-[Eu(tta)4] exhibits the improvement of photo physical properties (ƞ = 53.73 %) and is selected as the representative sample to examine the potential fluorescence sensing of metal cations. The hybrid POSS-min-[Eu(tta)4] has selective fluorescent quenching effect for different metal ions, especially for Cu2+. These results provide meaningful data for the multi-component assembly and responsive luminescent of photo functional hybrids based on modified ionic liquid and lanthanide, which can be expected to have potential application in organic light-emitting devices(OLED) or sensor.

Fabrication of highly ordered Cu2+/Fe3+ decorated polyhedral oligomeric silsesquioxane hybrids: How metal coordination influences structure

Incorporation of isolated metal centers into well-organized nanostructures is a promising route in the development of the next generation of chemical, magnetic and electronic devices. In this work, a layer-by-layer protocol to grow highly ordered thin films of metal-decorated organic-inorganic cage-like polyhedral oligomeric silsesquioxane (POSS) is introduced. The key strategy is to use metal ions (Cu2+ or Fe3+) as linker for the amino-functionalized cage-like POSS, which are self-assembled between arachidic acid layers during Langmuir–Schaefer deposition. The Langmuir–Schaefer films are examined by X-ray photoelectron spectroscopy, X-ray diffraction, grazing incidence wide-angle X-ray scattering and extended X-ray absorption fine structure in order to understand how the coordination of metal ions influences the structure in the course of the layer-by-layer formation of the films.

Main Chain-Type Block Copolymers through Atom Transfer Radical Polymerization from Double-Decker-Shaped Polyhedral Oligomeric Silsesquioxane Hybrids.

In this study, we synthesized two main chain–type block copolymers featuring hydrogen bond donor and acceptor segments through atom transfer radical polymerization (ATRP) using a bifunctionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticle as the initiator. Hydrosilylation of vinylbenzyl chloride at the two corners of a double-decker silsesquioxane (DDSQ) provided the bifunctionalized benzyl chloride initiator VBC-DDSQ-VBC, which we applied as a platform to prepare a main chain–type polystyrene homopolymer (PS-DDSQ-PS), the diblock copolymer poly(styrene–b–4-vinylpyridine) (P4VP-b-PS-DDSQ-PS-b-P4VP), and the diblock copolymer poly(styrene–b–tert-butoxystyrene) (PtBuOS-b-PS-DDSQ-PS-b-PtBuOS) through sequential ATRP. Selective hydrolysis of the tert-butoxyl units of PtBuOS-b-PS-DDSQ-PS-b-PtBuOS yielded the strongly hydrogen bonding diblock copolymer poly (styrene-b-vinylphenol) (PVPh-b-PS-DDSQ-PS-b-PVPh). We used Fourier transfer infrared spectroscopy, nuclear magnetic resonance spectroscopy, size exclusion chromatography, differential scanning calorimetry, mass-analyzed laser desorption ionization mass spectrometry, and transmission electron microscopy to investigate the chemical structures, thermal behavior, and self-assembled nanostructures formed by these main chain–type block copolymers based on DDSQ.