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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These ...
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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These results indicated that the incorporation of ...
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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These results indicated that the incorporation of m-POSS have little influence on the APU ...
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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These ...
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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These results indicated that the incorporation of ...
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... images of APU0 and APU8 are shown in Fig. 4. The diameter of most particles in Fig. 4a is below 40 nm, while the particles in Fig. 4b have a broader size distribution and there seem to be some particle agglomeration. The heterogeneity in particle size and shape would be caused by the incorporation of silicon element and strengthened by the increase of m-POSS content. These results indicated that the incorporation of m-POSS have little influence on the APU ...
Citations
... Interestingly, these specific peaks are not present in the composite samples, suggesting a transformation in the polymer chain's growth state. This change is likely due to the conjugation and coating effects of PEDOT on the GO sheets, implying successful in-situ polymerization of the PEDOT-GO nanocomposites, as observed across Fig. 8A to 8C [90][91][92]. ...
Perovskite solar cells (PSC) have emerged as highly efficient photovoltaic devices, boasting remarkable power conversion efficiencies (PCE) exceeding 25.5%. However, the incorporation of perovskite films raises environmental concerns due to associated toxicity, and PSC deteriorates over time due to material breakdown accelerated by heat, moisture, and undesired chemical reactions at interfaces. For example, employing titanium dioxide TiO₂ as the electron transport layer (ETL) and the organic semiconductor Spiro-OMeTAD as the hole transport layer (HTL) can lead to instability in the device. The broad bandgap of TiO₂ leads to charge carrier recombination in ETL, undermining device performance, along with the high cost and complex synthesis of Spiro-OMeTAD. Researchers have investigated several methods to tackle these challenges, including altering the interfacial structure and employing adaptable materials between the charge-gathering electrode and perovskite active layers. Due to their extensive bandgap and notable electron mobility, perovskite oxides are highly attractive; however, these materials encounter difficulties such as clustering, which can cause short circuits and leakage current. They also suffer from inefficient charge separation, surface hydrophilicity, and inadequate absorption of visible light. Furthermore, the addition of graphene particles to both compact and mesoporous TiO₂ layers, which act as electron-selective layers, aims to lower series resistance and boost electron extraction efficiency , achieving a peak PCE of 26.3%. These materials have garnered attention for their outstanding opto-electronic properties, superior stability, and non-toxic characteristics. This review extensively delves into the integration of graphene-based materials as interfacial layers and how that will affect the performance of PSC in terms of stability and efficiency.
... This implies that an increase in the filler materials leads to a corresponding decrease in the ductility of the samples but increased compressive strength. This result is similar to that obtained by Omotoyinbo et al. [33], Zhao et al. [59], and Jia et al. [60]. ...
This work was carried out to investigate the roles of quartz and marble on the performance of polyurethane particulate-filled composites. Prior to the mixing, the quartz and marble were pulverized and sieved to obtain an average particle size of less than 90 µm. Polyurethane (PU) was produced from isocyanate and polyol by a two-step method in which marble and quartz particles were incorporated in predetermined proportions. Three different weight ratios were utilized to investigate the physical, chemical, and mechanical behavior of the pristine rigid polyurethane foam (RPUF) and the marble and quartz-filled RPUF using analytical equipment such as FTIR, XRF, and SEM. The mechanical properties were performed according to the ASTM standards, where the compressive and flexural strengths were investigated using the universal testing machine. Overall, the RPUF shows the hydroxyl bands, while the principal elements of fillers are Calcium and Silicon. It was discovered from the results that adding these fillers improved the mechanical properties of the filled samples, where the compressive strength was enhanced.
... Polyurethane (PU) elastomer is also a hot topic in scientific research, especially in the field of intelligent materials such as the artificial electronic skin (e-skin) 12 owing to its excellent mechanical properties, 13,14 aging resistance, 15,16 good compatibility, 17,18 and easy modification. 19,20 Inspired by the selfhealing properties of biological tissues, PU is endowed with self-healing performance through hydrogen bonds, 21−23 disulfide bonds, 24,25 Diels−Alder bonds, 26,27 imine bonds, 28 metal coordination bonds 29,30 , and arylhydrazone bonds, 31,32 or a combination of several of these bonds 33 to address the damage issue caused during the use of TENG. Researchers have made certain research achievements on self-healing PUbased TENG. ...
Triboelectric nanogenerators (TENGs) are an emerging class of energy harvesting devices with considerable potential across diverse applications, including wearable electronic devices and self-powered sensors. However, sustained contact, friction, and incidental scratches during operation can lead to a deterioration in the electrical output performance of the TENG, thereby reducing its overall service life. To address this issue, we developed a self-healing elastomer by incorporating disulfide bonds and metal coordination bonds into the polyurethane (PU) chain. The resulting elastomer demonstrated exceptional toughness, with a high value of 85 kJ m^–3 and an impressive self-healing efficiency of 85.5%. Specifically, the TENG based on that self-healing PU elastomer generated a short circuit current of 12 μA, an open circuit voltage of 120 V, and a transfer charge of 38.5 nC within a 2 cm × 2 cm area, operating in contact-separation mode. With an external resistance of 20 MΩ, the TENG achieved a power density of 2.1 W m–2. Notably, even after self-healing, the electrical output performance of the TENG was maintained at 95% of the undamaged device. Finally, the self-healing TENG was employed to construct a self-powered noncontact sensing system that can be applied to monitor human motion accurately. This research may expand the application prospects of PU materials in future human–computer interaction and self-powered sensing fields.
... This improvement was mainly affected by the dynamics and slow relaxation effect of the SP/WP/QCS molecular chain. Meanwhile, the formation of hard domains limited the movement of small molecules in the polymer, resulting in the decrease of the mobility of polymer chains (Zhao et al., 2019a). The damping properties of films were Fig. 4. SEM surface topography images. ...
... XRD diffractograms of 8OHPOSS and studied NIPUs are shown in Fig. 5. Interestingly, there are no traces of crystalline peaks on the diffractograms of the composites despite the highly crystalline nature of 8OHPOSS. Uniform POSS dispersion is maintained even at high POSS loading, exhibiting dispersion comparable [47] or even better [48,49] than in systems where POSS is covalently incorporated into a polyurethane network. Uniform POSS dispersion in physically modified composites results from compatibility between the polar matrix and the polar -OH groups at the end of 8OHPOSS substituent groups. ...
PEO-based non-isocyanate polyhydroxyurethane (NIPU, PHU) networks physically modified with octa(3-hydroxy-3-methylbutyldimethylsiloxy)POSS (8OHPOSS) were synthesized via one-pot one-step approach. POSS was introduced into the polymer matrix in the amount of 1–10 wt%. Polar hydroxyls on the vertex groups of POSS allowed for uniform dispersion even up to high loadings (10 wt%). Composites exhibit enhanced thermal stability in comparison to the pristine matrix. FTIR analysis confirmed that POSS strengthens the hydrogen bonding in the material. Upon POSS introduction, plasticization was observed with a peculiar trend change at POSS loadings over 5 wt%. Glass transition temperature of highly crystalline 8OHPOSS was measured and reported to be at around 3 °C. NIPUs at hand exhibit high water absorption (around 200 wt%) typical for hydrogels. Swelling studies show that 8OHPOSS enhances PHUs hydrogels absorption capacity in phosphate-buffered saline (PBS). Higher absorption capacity in PBS solution in comparison to distilled water is an uncommon phenomenon in hydrogels.
... The reactions between DAH, DAP and EP group are lower than that between amino group and EP group, so some flame retardants may not react with EP resulting in lower υ. Interestingly, the EPC has two Tan δ peaks meaning microphase separation in EP system which should be related to its impact strength [34,35]. Moreover, the υ values for EPC4 and EPC6 are both larger than that of EP indicating the reactivity of DAC is higher than that of DAH and DAP. ...
... The interplay between the loss modulus and storage modulus provides an accurate representation of the interaction between different segments and the degree of micro-phase separation [32,33]. DMA yields more precise results in analyzing the degree of micro-phase separation than DSC as it combines data related to the modulus properties [34,35]. ...
The development of damping and tire materials has led to a growing need to customize the dynamic viscoelasticity of polymers. In the case of polyurethane (PU), which possesses a designable molecular structure, the desired dynamic viscoelasticity can be achieved by carefully selecting flexible soft segments and employing chain extenders with diverse chemical structures. This process involves fine-tuning the molecular structure and optimizing the degree of micro-phase separation. It is worth noting that the temperature at which the loss peak occurs increases as the soft segment structure becomes more rigid. By incorporating soft segments with varying degrees of flexibility, the loss peak temperature can be adjusted within a broad range, from −50 °C to 14 °C. Furthermore, when the molecular structure of the chain extender becomes more regular, it enhances interaction between the soft and hard segments, leading to a higher degree of micro-phase separation. This phenomenon is evident from the increased percentage of hydrogen-bonding carbonyl, a lower loss peak temperature, and a higher modulus. By modifying the molecular weight of the chain extender, we can achieve precise control over the loss peak temperature, allowing us to regulate it within the range of −1 °C and 13 °C. To summarize, our research presents a novel approach for tailoring the dynamic viscoelasticity of PU materials and thus offers a new avenue for further exploration in this field.
... PU-HTPB reinforced with these two POSS increases the mechanical strength and reduces the elongation of the system (Fig. 23) [91]. Creating a chemical bond between POSS and polymer increases the mechanical properties of the polymer [98]. POSS nanostructures, as rigid PU segments, increase mechanical strength and reduce the elongation of the polymer [96]. ...
One of the approaches to improve the properties of polymers is to use additives in them. In the last few years, nanoscale additives have received attention due to the favorable properties they give to polymers in low concentrations. POSS or polyhedral oligomeric silsesquioxane has unique properties due to its nanometer size and organic–inorganic nature. The rigid structure of POSS and its compatibility with all types of polymers make their use attractive in various polymer industries. The concentration, structure of the mineral core, and type of POSS organic groups can affect the final properties of polymers containing these nanostructures. Chemical mixing of POSS with polymer increases the viscosity of the system, while physical mixing decreases the viscosity of the polymer. These nanostructures can improve properties such as tensile strength, modulus, and toughness of the polymer. Polymers with low concentrations of POSS have the advantage of high thermal stability and low flammability, which makes them ideal for applications in the aerospace industry where materials must withstand extreme temperatures and harsh environments. In addition, the low dielectric constant of POSS-containing polymers makes them useful for use in electronic components. The high specific surface of POSS allows the use of these nanostructures as supports for various catalysts. POSS is used in a wide range of industries including aerospace, biomedical, electronics and chromatography columns, etc.
Graphical Abstract
... FTIR spectra of neat PLA and AH-POSS along with those of nanohybrids are shown in Fig. 3. AH-POSS showed a strong peak at 1085 cm −1 with a shoulder at 1037 cm −1 [32,33], characteristic peaks at 1229 and 899 cm −1 (Si-C stretching) [32,34,35], 837 and 745 cm −1 (Si-C wagging) [32,35], and a well-defined peak centered at 1635 cm −1 resulting from the vibration of the allyl double bond of the functional group (Fig. 3b) [36]. The C-H stretching and deformation vibrations of the isobutyl substituents of AH-POSS were observed at 2953/2871 cm −1 and 1464/1367 cm −1 , respectively [35,37]. All nanohybrids displayed similar peaks to those characteristic of PLA (Fig. 3a) at 2995/2945 and 2880 cm −1 due to CH 3 asymmetric/symmetric stretching vibration and CH stretching, respectively [6,38], 1749 cm −1 corresponding to the C=O stretching vibration of carbonyl group [38,39], 1453, 1382 and 1360 cm −1 due to C-H deformation in CH 3 and CH [6,38], 1266, 1180 and 1080 cm −1 corresponding to the asymmetric and symmetric stretching vibration of C-O bond in the C-O-C group [39,40], and at 1043 cm −1 due to C-CH 3 symmetrical stretching [38,39]. ...
... The XRD patterns of the nanohybrids (Fig. 6a) displayed similar amorphous hallows as neat PLA and the reflections characteristic to the AH-POSS crystals, whose intensity increased with the increase in nanoparticles content. This may indicate that the POSS moieties were chemically linked to PLA according to a previously published report [37]. ...
Polysilsesquioxanes are extensively studied as durable and anti-adherent coatings for medical devices due to their superhydrophobic properties. However, their particular influence on the thermo-mechanical properties and biocompatibility of poly(lactic acid) (PLA)-based materials obtained by melt compounding is scarce. Herein, a facile and promising method to improve the performances of PLA for biomedical applications via the incorporation of different mass proportions of POSS nanoparticles with allyl-heptaisobutyl (AH-POSS) substituent through a melt-blending technique is proposed. The thermal, morpho-structural, mechanical properties at room (RT) and body temperatures (BT), and in vitro biocompatibility of the developed PLA/AH-POSS nanohybrids were investigated. AH-POSS nanoparticles were found to have simultaneous nucleation and plasticizing effects on the PLA nanohybrids, inducing enhanced thermal resistance and easy control of crystallinity while preserving PLA’s biocompatibility. An interesting effect of AH-POSS on the mechanical properties of PLA at body temperature was observed. These results indicate the considerable potential of the PLA/AH-POSS nanohybrids obtained by melt compounding in the fabrication of biomedical devices.
... POSS is an inorganic and organic component with a rigid structure [19,20] which is associated with the chemical and physical bonds to form the synergistic effect to efficiently perform the thermal, mechanical and surface properties. Thus, it becomes the most potential representative in the process of the material structure design [21][22][23][24][25]. Ajaya K. Nanda et al. [26] studied the effect of diamino-POSS on the properties of polyurethane materials. The tensile strength and glass transition temperature (T g ) were significantly improved by the experimental results. ...
Waterborne polyurethane are more eco-friendly materials due to lower volatile organic compounds (VOCs, mainly isocyanates) content than the alternative materials. However, these rich hydrophilic groups polymers have not yet reached good mechanical properties, durability and hydrophobicity behaviors. Therefore, hydrophobic waterborne polyurethane has become a research hotspot, attracting significant attention. In this work, firstly, a novel fluorine-containing polyether P(FPO/THF) was synthesized by cationic ring-opening polymerization of 2-(2,2,3,3-tetrafluoro-propoxymethyl)-oxirane (FPO) and tetrahydrofuran (THF). Secondly, fluorinated polymer P(FPO/THF), isophorone diisocyanate (IPDI) and hydroxy-terminated polyhedral oligomeric silsesquioxane (POSS-(OH)8) were used to prepare a new fluorinated waterborne polyurethane (FWPU). Hydroxy-terminated POSS-(OH)8 was used as a cross-linking agent, while dimethylolpropionic acid (DMPA) and triethylamine (TEA) were used as a catalyst. Four kinds of waterborne polyurethanes (FWPU0, FWPU1, FWPU3, FWPU5) were obtained by adding different contents of POSS-(OH)8 (0%, 1%, 3%, 5%). The structures of the monomers and polymers were verified by 1H NMR and FT-IR, and the thermal stabilities of various waterborne polyurethanes were analyzed by thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC). As the results, the thermal analysis showed that the FWPU performed the good thermal stability and the glass transition temperature could reach at about −50 °C. The FWPU1 film exhibited that the elongation at break was 594.4 ± 3.6% and the tensile strength at break was 13.4 ± 0.7 MPa, elucidating that the FWPU1 film developed the excellent mechanical properties relative to the alternative FWPUs. Further, the FWPU5 film performed the promising properties, including the higher surface roughness of FWPU5 film (8.41 nm) obtained by the atomic force microscope (AFM) analysis, and the higher value of water contact angle (WCA) at 104.3 ± 2.7°. Those results illustrated that the novel POSS-based waterborne polyurethane FWPU containing a fluorine element could develop the excellent hydrophobicity and mechanical properties.
