The influence of poly(titanium oxide) obtained using the sol-gel method in 2-hydroxyethyl methacrylate medium on the viscoelastic and thermophysical properties of interpenetrating polymer networks (IPNs) based on cross-linked polyurethane (PU) and poly(hydroxyethyl methacrylate) (PHEMA) was studied. It was found that both the initial (IPNs) and organo-inorganic interpenetrating polymer networks (OI IPNs) have a two-phase structure by using methods of dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The differential scanning calorimetry methods and scanning electron microscopy (SEM) showed that the presence of poly(titanium oxide) increases the compatibility of the components of IPNs. It was found that an increase in poly(titanium oxide) content leads to a decrease in the intensity of the relaxation maximum for PHEMA phase and an increase in the effective crosslinking density due to the partial grafting of the inorganic component to acrylate. It was shown that the topology of poly(titanium oxide) structure has a significant effect on the relaxation behavior of OI IPNs samples. According to SEM, a uniform distribution of the inorganic component in the polymer matrix is observed without significant aggregation.
This study presents a novel silver nanoparticle ink formulation designed for inkjet printing applications using terpineol as an eco-friendly solvent and butylamine as a stabilizer to ensure stability, high conductivity, and compatibility with inkjet technology. Silver nanoparticles were synthesized using a modified one-pot method in the presence of highly effective stabilizers and surface modifiers such as oleic acid and oleylamine, resulting in uniform particles of less than 10 nm in size, which were then dispersed in a mixture of terpineol and butylamine. The resulting ink demonstrated exceptional stability over 85 days, maintaining optimal rheological properties for inkjet printing. The ink exhibited a perfect jetting performance. We were able to obtain silver conductive patterns reaching 81% of bulk silver conductivity. These results highlight the ink’s promise for scalable, sustainable manufacturing, combining environmental advantages with high-performance functionality.
30 May 2024 in Latvian Journal of Physics and Technical Sciences
The paper investigates the process of phase separation and morphology of organic-inorganic interpenetrating polymer networks (OI IPNs) based on the cross-linked polyurethane (PU), poly(hydroxyethyl methacrylate) (PHEMA) and poly(titanium oxide) (–TiO2–)n obtained by solgel method in the presence of poly(oxypropylene glycol) (POPG) at various molar ratio of titanium (IV) isopropoxide (Ti(OPri)4) and water. It has been established that the phase separation in OI IPNs depends on the kinetics of PHEMA-component formation and it occurs through the mechanism of the spinodal decomposition. It has been shown that by varying the ratio of IPNs components, content of inorganic component and Ti(OPri)4/H2O molar ratio it is possible to control the phase separation process and obtain OI IPNs with a different phase structure.
The physical nature of the ferroelectric (FE), ferrielectric (FEI) and antiferroelectric (AFE) phases, their coexistence and spatial distributions underpin the functionality of antiferrodistortive (AFD) multiferroics in the vicinity of morphotropic phase transitions. Using Landau-Ginzburg-Devonshire (LGD) phenomenology and a semi-microscopic four sublattice model (FSM), we explore the behavior of different AFE, FEI and FE long-range orderings and their coexistence at the morphotropic phase boundaries in FE-AFE-AFD multiferroics. These theoretical predictions are compared with the experimental observations for dense Bi1-yRyFeO3 ceramics, where R is Sm or La atoms with the fraction 0 < y< 0.25, as confirmed by the X-ray diffraction (XRD) and Piezoresponse Force Microscopy (PFM). These complementary measurements were used to study the macroscopic and nanoscopic transformation of the crystal structure with the doping. The comparison of the measured and calculated AFE/FE phase fractions demonstrate that the LGD-FSM approach well describes the experimental results obtained by XRD and PFM for Bi1-yRyFeO3. Hence, this combined theoretical and experimental approach provides further insight into the origin of the morphotropic boundaries and coexisting FE and AFE states in model rare-earth doped multiferroics.
4 August 2022 in Journal of Thermal Analysis and Calorimetry