Search

The importance of biopolymer-based nanocomposites in food packaging is growing significantly. Therefore, in the present study, we aim to examine the impact of zinc oxide (ZnO), polyhedral oligomeric silsesquioxanes (POSS), and, for the first time, their hybrid on polycaprolactone (PCL) nanocomposites. For this matter, different concentrations of 1, 3, and 5 wt% of each nanoparticle and the hybrid were incorporated into the PCL nanocomposites via the solution casting method. Their chemical structures and interactions, crystalline structures, and morphology were investigated by FT-IR, WAXD, and SEM. Moreover, it was observed through contact angle and surface free energy experiments that an increase in the nanoparticle concentration corresponded to an increase in the contact angle values. The incorporation of hybrid POSS and ZnO equilibrated well between Young’s modulus, tensile strength, and elongation of the samples in their single status. Accordingly, the addition of the hybrid nanoparticles up to 3 wt% significantly increased the modulus and yield strength of PCL nanocomposites without any significant sacrifice in toughness. Also, PPZ3 (containing an optimal 3%wt. of hybrid nanoparticles) demonstrated the lowest permeability against both water vapor and O2 gas, exhibiting reductions of approximately 30 and 55% when compared to pristine PCL. Finally, the antibacterial properties of the nanocomposite films were investigated for S. aureus and E. coli bacteria and revealed. In addition to the antibacterial properties of ZnO and POSS nanoparticles, increasing the concentration of hybrid nanoparticles up to 5 wt% expanded S. aureus’s inhibitory zone. The balanced mechanical, and barrier characteristics, enhanced morphologies, and antibacterial effects of the novel hybrid nanocomposites present novel opportunities in the field of food packaging. [ABSTRACT FROM AUTHOR]

This paper proposes a digital-to-time converter (DTC)-assisted fractional-N wide-bandwidth all-digital phase-locked loop (ADPLL) with a fine-resolution time-to-digital converter (TDC). The TDC employs a two-channel time-interleaved time-domain register with an implicit adder/subtractor realizing an error-feedback topology. Such an error-feedback unit of a first-order $\Delta \Sigma $ -TDC can be cascaded as a multi-stage noise shaping configuration to achieve higher-order noise-shaping and, thereby, low in-band phase noise (PN) of the ADPLL. A digitally controlled oscillator with a transformer and a pair of cross-coupled NMOS amplifiers exploits magnetic and capacitive coupling to achieve nearly an octave frequency coverage, i.e., 1.73–3.38 GHz (after a $\div $ 2 division). Fabricated in 40-nm CMOS, the ADPLL achieves better than −110-dBc/Hz in-band PN and occupies an active area of 0.5 mm2. With a 50-MHz reference clock, a 2-GHz output RF clock, and a loop bandwidth of 800 kHz, this prototype achieves 420-fs $_{{\mathrm{rms}}}$ jitter, integrated from 1-kHz to 30-MHz offset, while drawing 10.7 mW. [ABSTRACT FROM AUTHOR]