Improvement of the mechanical properties of nano‐TiO₂/poly(vinyl alcohol) composites by enhanced interaction between nanofiller and matrix

Abstract

Surface-carboxylated nano-TiO 2 was used to prepare poly (vinyl alcohol) (PVA) nanocomposites to improve the dispersity of nano-TiO 2 particles in PVA and to enhance the interaction between nanofiller and matrix. The effects of the extents of carboxylation and carboxylated nano-TiO 2 loading on mechanical properties of the nanocomposites were investigated. The results show that the tensile strength of the nanocomposites was greatly improved, both by increasing the carboxylated nano-TiO 2 loading and by the extent of carboxylation of the nanoparticles, compared with unmodified nano-TiO 2 . The storage modulus within the rubbery state increased and the loss tangent decreased with increasing À ÀCOOH content on the TiO 2 surface and with increasing carboxylated nano-TiO 2 loading. These observations were attributed to a high dispersion of modified nano-TiO 2 in the PVA matrix and to crosslinking between À ÀOH groups in PVA chains and À ÀCOOH moieties on inorganic nanoparticle surfaces. POLYM.

Immobilization of TiO2 nanoparticles in polymeric substrates by chemical bonding for multi-cycle photodegradation of organic pollutants

“…3. It is well known that there are always some active OH groups located on the surfaces of nano TiO 2 [41]. Under heattreatment, these OH groups on TiO 2 surfaces can form Ti O C bonds with the OH groups in PVA molecular chains through a dehydration reaction.…”

“…The crystalline regions and Ti O C bonds served as physical and chemical crosslinking points, respectively, to form the three-dimensional network, endowing the hybrid film with excellent mechanical ability and swelling ability in water. The amorphous region in the network possesses large free [41]. c Calculated from TGA.…”

Film formation and mechanical properties of an opaque titanium dioxide and transparent polyvinyl alcohol composite films

“… Therefore, as shown in Figure , the peak observed at around 3140 cm −1 may be assigned to the stretching vibration of H bonded OH groups in PVA, while another broad peak centered at around 3360 cm −1 can correspond to nonbonded OH stretching vibration. It was reported that in the spectrum of TiO 2 , the peak at around 3414 to 3490 cm −1 was assigned to OH stretching vibration of water molecules adsorbed on the surface of the TiO 2 nanoparticles . In the spectrum of 5 wt% TiO 2 films, because TiO 2 nanoparticles affect the OH spectral region significantly via intermolecular interactions of the OH groups of water molecules adsorbed on the surfaces of TiO 2 nanoparticles with PVA molecules, there appears a broad peak from around 2800 to 3600 cm −1 as seen in Figure .…”

“…Prominent band frequencies and their assignments in pure PVA films and TiO 2 were summarized in Table by using the references in the literature . Here, as it is seen in Figure , the spectral region where the band at around 620 cm −1 corresponding to out of plane OH bending in pure PVA films was changed after the addition of TiO 2 nanoparticles into PVA films.…”

Surface Modification of ZrO2 Nanoparticles with Biosafe Coupling Agents, Preparation of Poly(vinyl pyrrolidone) Nanocomposites: Optical, Thermal, and Morphological Studies

“…Therefore, it is very important to develop methods to control the dispersion-aggregation phenomena of NPs to apply them into polymer matrix. 17 Over the past two decades, surface modification of NPs with different kinds of modifier agents has been extremely investigated. 18 Besides these, biosafe modifiers have attracted a great deal of attention for modification of NPs.…”