Poly(lactic acid)‐Based Film with Excellent Thermal Stability for High Energy Density Capacitor Applications

Abstract

Dielectric capacitors play a key role in high power electronics, electric vehicles, and medical devices. Due to the biodegradability, high thermal stability, and ease of processing, poly(lactic acid)-based (PLA) films are widely used in applications of tissue engineering, actuators, and sensors. In this investigation, PLA films are prepared using a solution casting method for high energy density capacitor applications. It is found that the stretched poly(d-lactic acid) (PDLA) film exhibits an energy density and charge discharge efficiency of 18.5 J cm −3 and 95%, respectively, at room temperature. Furthermore, after a heating time of 30 min at 100 °C, it is found that the energy density and chargedischarge efficiency of the stretched PDLA films are maintained at 11.2 J cm −3 and 76%, respectively. In comparison, the energy density and efficiency of the stretched PDLA film are 1.03-fold and 53% higher, respectively, than those of the stretched poly(vinylidene fluoride-hexafluoropropylene) film at 100 °C with the same heat treatment. Compared with a high temperature polyimide material, the energy density of the stretched PDLA film is 1.98-fold higher at 100 °C. The PLA-based material shows great promise for application in high energy density capacitors operating at a high temperature (100 °C).

Degradable Hemostatic Antibacterial Zein Nanofibrous Mats as Anti‐Adhesive Wound Dressing

“…SPODA‐modified TiO 2 improved the dispersion of the nanoparticles in chloroform due to the presence of the long chain alkyl group in such quaternary ammonium compounds. [ 27,28 ] As displayed in Figure a, TiO 2 ‐SPODA nanoparticles uniformly covered the zein nanofibers surface, even the surfaces inside the nanofibrous mats. The spot elemental mappings displayed the distribution of C, N, O, Si, and Ti in Figure 3a, respectively, and further confirmed the uniformity of TiO 2 ‐SPODA coating.…”

“…It is recommended that the appropriate WVTR range for wound dressings is from 2000 mL m −2 per day to 2500 mL m −2 per day to ensure optimal wound healing. [ 27,37 ] As shown in Figure a, the WVTRs of zein mat (2303 ± 179 mL m −2 per day), cross‐linked zein mat (2277 ± 165 mL m −2 per day), and zein/TiO 2 ‐SPODA mat (2194 ± 143 mL m −2 per day) were used to represent the moisture permeability of the mats. The results indicate that the zein/TiO 2 ‐SPODA dressing could keep a moist environment around the wound for healing.…”

“…The antibacterial efficiencies of cross‐linked zein and zein/TiO 2 ‐SPODA nanofibrous mats against Gram‐positive S. aureus (ATCC 6538) and Gram‐negative E. coli O157:H7 (ATCC 43 895) were evaluated according to the reported methods with a slight modification. [ 27,28 ] Briefly, 20 µL of bacterial suspension (10 6 CFU mL −1 ) was sandwiched between two nanofibrous mats (2.54 cm × 2.54 cm) to ensure effective contact. After contact times of 60 and 120 min, the sandwich configuration formed by bacterial suspension and nanofibrous mats was soaked in 5 mL of aseptic PBS solution and vortexed for 250 s to resuspend all bacteria.…”

Poly(l‐Lactic Acid) Nanofiber‐Based Multilayer Film for the Electrical Stimulation of Nerve Cells

“… $$\[ \begin{array}{*{20}{c}}{x = \left( {\frac{{\Delta {H_{\rm{m}}}}}{{\Delta {H_f}}}} \right) \times \;100\\end{array} \]$$where Δ H f represents the melting enthalpy of the PLLA films with 100% crystallization, and ∆ H m is the melting enthalpy of the PLLA film. [ 29 ] From the data, the crystallinity increased with increasing annealing temperature. As the calculated result shows in Table 1 (in the supporting information).…”

Sustainable Macromolecular Materials in Flexible Electronics

“…Thanks to the appropriate properties of PLA, it can be used to respond to the increasing need for polymeric materials in the field of electronics. [201,202] PLA, which is a renewable and sustainable biopolyester, can be an alternative to overcome the limiting situation in the production of synthetic materials in terms of storing the energy required for the manufacture of electronic products and the operation of small devices. In addition, it is one of the most important biopolymer candidates because of its biocompatibility and noncytotoxic properties, which are an important requirement in bioelectronic studies and wearable flexible devices.…”