Morphological and thermal properties of nanocomposites contain poly(amide-imide) reinforced with bioactive N-trimellitylimido-L-valine modified TiO2 nanoparticles

Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2

The polymer-inorganic nanoparticles composite membranes are the latest solutions for multiple physicochemical resistance and selectivity requirements of membrane processes. This paper presents the production of polysulfone-silica microfiber grafted with titanium dioxide nanoparticles (PSf-SiO₂-TiO₂) composite membranes. Silica microfiber of length 150-200 μm and diameter 12-15 μm were grafted with titanium dioxide nanoparticles, which aggregated as microspheres of 1-3 μm, applying the sol-gel method. The SiO₂ microfibers grafted with nano-TiO₂ were used to prepare 12% polysulfone-based nanocomposite membranes in N-methyl pyrrolidone through the inversion phase method by evaporation. The obtained nanocomposite membranes, PSf-SiO₂-TiO₂, have flux characteristics, retention, mechanical characteristics, and chemical oxidation resistance superior to both the polysulfone integral polymer membranes and the PSf-SiO₂ composite membranes. The antimicrobial tests highlighted the inhibitory effect of the PSf-SiO₂-TiO₂ composite membranes on five Gram (-) microorganisms and did not allow the proliferation of Candida albicans strain, proving that they are suitable for usage in the oral environment. The designed membrane met the required characteristics for application as a functional barrier in guided bone regeneration.

Potentially eco-friendly poly (amide–ester–imide)/diacid-grafted titanium dioxide/modified montmorillonite nanocomposites containing natural amino acids

The progress of organic/inorganic composite materials has been specifically trendy in the last decade. This article focused on the fabrication and characterization of nanocomposites (NCs) with two different nanoparticles. Poly(amide–ester–imide) (PAEI) matrix was prepared by reacting N,N′-(1,3,5,7-tetraoxo-5,7-dihydropyrrolo[3,4-f]isoindole-2,6(1H,3H)-diyl)bis(4-hydroxybenz-amide) with N-trimellitylimido-l-leucine (TML) via tosyl chloride, pyridine, and N,N-dimethylformamide as a condensing agent. The surface of titanium dioxide (TiO2) nanoparticles was modified with diacid TML. Diacid-grafted TiO2 (D-TiO2) was mixed with the obtained PAEI and sonicated to form a PAEI/D-TiO2 NC. Then, the surface of a sodium montmorillonite (MMT) was modified through intercalation with the cationic surfactant of l-leucine using an ion-exchange mechanism. PAEI/D-TiO2/organically modified montmorillonite composites at three different weight fractions of silicate layer were prepared via solution intercalation method. The spectral, morphological, and thermal properties of the aforementioned NCs were investigated in terms of several experimental techniques, including Fourier transform infrared spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction, thermogravimetric analysis, and transmission electron microscopy (TEM). The obtained novel NCs improved thermal stability from neat polymer. Photographs showing TEM and FESEM results also illustrated that the nanofillers were rather uniformly distributed in the polymer matrix.

A green route for the synthesis of novel optically active poly(amide–imide) nanocomposites containing N-trimellitylimido-l-phenylalanine segments and modified alumina nanoparticles

In the present study, novel optically active poly(amide–imide)/alumina nanocomposites (PAI/Al2O3 NCs) containing different amounts of modified α-Al2O3 nanoparticles (NPs) were synthesized using the ultrasonic-assisted technique. To improve NPs dispersion and increase the possible interaction between NPs and PAI matrix, the surface of α-Al2O3 NP was modified with bioactive diacid coupling agent. The PAI chains were formed from the polycondensation of N-trimellitylimido-l-phenylalanine diacid with 1,5-diamino naphthalene under green conditions. The obtained polymer and inorganic metal oxide NPs were used to prepare chiral PAI/Al2O3 NCs through the ultrasonic irradiation. PAI/Al2O3 NCs were characterized by Fourier transform infrared spectra, x-ray diffraction patterns, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and ultraviolet–visible (UV-Vis). TGA results confirmed that the heat stability of the prepared NP-reinforced composites was improved compared with the pure polymer. In addition, TEM and FESEM images showed that NPs were dispersed into the polymer matrix at nanoscale.