Organic-inorganic nanocomposite films consisting of surface functionalized halloysite nanotube (HNT) and poly (vinyl alcohol) (PVA) with improved mechanical and thermal properties were prepared. The ...surface of HNT was modified with boronic acid by two different methods. In the first method, a boronic acid group bearing a triethoxysilane was synthesized and used to modify HNT directly. In the second method, HNT was modified by 3-aminopropyltriethoxysilane (APTES) and 4-formylphenylboronic acid sequentially. The surface-modified HNT was characterized by ζ-potential, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The nanocomposite films were prepared by solvent casting, followed by compression molding. The molecular aggregation structure and physicochemical properties were investigated by UV–Vis spectrophotometry, differential scanning calorimetry, wide-angle X-ray diffraction, tensile test, and dynamic mechanical analysis.
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Recently, flexible devices using intrinsically conductive polymers, particularly poly(3,4-ethylenedioxythiophene) (PEDOT), have been extensively investigated. However, most flexible wiring ...fabrication methods using PEDOT are limited to two-dimensional (2D) fabrication. In this study, we fabricated three-dimensional (3D) wiring using the highly precise 3D printing method of stereolithography. Although several PEDOT fabrication methods using 3D printing systems have been studied, few have simultaneously achieved both high conductivity and precise accuracy. In this study, we review the post-fabrication process, particularly the doping agent. Consequently, we successfully fabricated wiring with a conductivity of 16 S cm
. Furthermore, flexible wiring was demonstrated by modeling the fabricated wiring on a polyimide film with surface treatment and creating a three-dimensional fabrication object.
Controlling the phase-separated structure of polymer alloys is a promising method for tailoring the properties of polymers. However, controlling the morphology of phase-separated structures is ...challenging. Recently, phase-separated structures have been fabricated via 3D printing; however, only a few methods that enable on-demand control of phase separation have been reported. In this study, laser-scanning stereolithography, a vat photopolymerization method, is used to form a phase-separated structure via polymerization-induced microphase separation by varying the scanning speed and using macro-reversible addition/fragmentation chain transfer (macro-RAFT) agents with different average molar masses, along with multiarmed macro-RAFT agents; such structures were used to fabricate 3D-printed parts. Various phase-separated morphologies including sea-island and reverse sea-island were achieved by controlling the laser scanning speed and RAFT type. Heterogeneous structures with different material properties were also achieved by simply changing the laser scanning speed. As the deformation due to shrinkage in the process of cleaning 3D-printed parts depends on the laser scanning speed, shape correction was introduced to suppress the effect of shrinkage and obtain the desired shape.
'Imogolite', a tubular inorganic nanotube surface, was modified with a peptide oligomer to prepare a hybrid hydrogel. The formation of the gels was confirmed by conducting a vial inversion test and ...rheological measurements. The surface modification of imogolite with the peptide oligomer was verified by performing thermogravimetric analysis and circular dichroism measurements. Furthermore, the formation of the network-like morphology of the prepared hydrogel was confirmed by scanning force microscopy.
'Imogolite', a tubular inorganic nanotube surface, was modified with a peptide oligomer to prepare a hybrid hydrogel.
A hydrolysis-resistant polymer bearing new quasi-choline phosphate (quasi-CP) structures as side groups, poly(2-methacryloyloxyethyl choline methylphosphonate) (
), was designed and synthesized. ...Radical polymerization and sub-surface-initiated radical polymerization were used to prepare homopolymer and polymer brush on polymer substrates. Hydrolytic stability and hydrophilicity of the polymer were confirmed by nuclear magnetic resonance and contact angle measurements. Furthermore, the hydration states were investigated using Fourier-transform infrared spectroscopy and differential scanning calorimetry. The similar hydration behavior of
to poly(2-methacryloyloxyethyl phosphorylcholine) (
) sheds light on understanding the interfacial functions of quasi-CP-bearing zwitterionic biomaterials.
A conductive polymer thin film having choline phosphate as the side group was prepared. Quartz crystal microbalance (QCM) was employed to evaluate the adsorption of the model protein, bovine serum ...albumin (BSA), on the films deposited on indium tin oxide (ITO) electrodes. Cell adsorption on the film was evaluated by a fibroblast NIH3T3.
The interactions between an exchangeable mimic of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), Phos(±), with an exchangeable mimic of cholesterol, Chol, have been analyzed in fluid bilayers by ...means of nearest-neighbor recognition measurements. These interactions have been found to be very similar to those of an exchangeable mimic of 1,2-dipalmitoyl-sn-glycerol-3-phospho-(1′rac-glycerol) (DPPG), Phos(−), interacting with Chol. Thus, both phospholipids have a similar preference for becoming nearest-neighbors of Chol in the liquid-ordered (l 0) phase, and both mix, ideally, with Chol in the liquid-disordered (l d) phase. These findings, together with the almost negligible screening effects found for the latter, provide strong evidence that electrostatic forces play a minor role in the preference that both phospholipids have in becoming a favored nearest-neighbor of Chol. They also imply that the main driving force for forming the liquid-ordered phase, and for defining the lateral organization of this phase, is an intrinsic affinity that high-melting lipids and cholesterol have for each other.
The development of handling technology for microscopic biological samples such as cells and spheroids has been required for the advancement of regenerative medicine and tissue engineering. In this ...study, we developed micro-tweezers with a compliant mechanism to manipulate organoids. The proposed method combines high-resolution microstereolithography that uses a blue laser and topology optimization for shape optimization of micro-tweezers. An actuation system was constructed using a linear motor stage with a force control system to operate the micro-tweezers. The deformation of the topology-optimized micro-tweezers was examined analytically and experimentally. The results verified that the displacement of the tweezer tip was proportional to the applied load; furthermore, the displacement was sufficient to grasp biological samples with an approximate diameter of several hundred micrometers. We experimentally demonstrated the manipulation of an organoid with a diameter of approximately 360 µm using the proposed micro-tweezers. Thus, combining microstereolithography and topology optimization to fabricate micro-tweezers can be potentially used in modifying tools capable of handling various biological samples.
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