We investigated experimentally, analytically, and numerically the formation process of double emulsion formations under a dripping regime in a tri-axial co-flow capillary device. The results show that mismatches of core and shell droplets under a given flow condition can be captured both experimentally and numerically. We propose a semi-analytical model using the match ratio between the pinch-off length of the shell droplet and the product of the core growth rate and its pinch-off time. The mismatch issue can be avoided if the match ratio is lower than unity. We considered a model with the wall effect to predict the size of the matched double emulsion. The model shows slight deviations with experimental data if the Reynolds number of the continuous phase is lower than 0.06 but asymptotically approaches good agreement if the Reynolds number increases from 0.06 to 0.14. The numerical simulation generally agrees with the experiments under various flow conditions.

The photoluminescence (PL) properties of silicon-on-insulator (SOI) samples, modified by the Si⁺ self-ion-implantation (SII) into Si thin film followed by annealing, have been well investigated. The well-known W-line can also be observed in SII SOI samples, its emitting behavior and structural evolution have been discussed in this article. The parallel PL pattern trend and the similar changes of temperature-dependent intensity suggest that luminescence center of I₁ and I₂ peaks located in the near-infrared band originates from the same interstitial-clusters (I_nCs). The PL peak at 1.762 eV can be ascribed to the quantum confinement (QC) from small-sized Si nanocrystals. Based on the electron spin resonance (ESR) experiments and the variation of normalized PL intensities at different annealing temperature (T_A), the neutral oxygen vacancy (NOV) [O₃≡Si-Si≡O₃] is proposed to be responsible for the blue emission of P₂ and P₃ peaks, whose intensity can be restrained by the existence of the paramagnetic E₁' defects [O₃≡Si⁺]. The density of E₁' defect is found to reduce with the increase of annealing temperature (T_A). Our results provide a useful method to identify the origin of luminescence centers and pave a way for the application of new type optical defects on silicon based light emitting devices (LEDs).

Combined emulsion‐hydrogel systems offer versatile platforms for controlled release and enhanced emulsion stability across various applications. This study introduces alginate‐based core‐shell structures encapsulating oil‐in‐water emulsions. Mineral oil is emulsified using an aqueous solution containing carboxymethyl cellulose (CMC), calcium lactate, and non‐ionic surfactants (Tween 20 and Span 80) at varying concentrations. The influence of oil volume fraction and surfactant concentration on emulsion stability is assessed through bottle tests, droplet size distribution, and zeta potential analysis. Emulsions with 30 v% oil and 2 wt.% Tween 20 demonstrate the highest stability, remaining stable for up to seven days. The optimized emulsion exhibits a small droplet size of 0.55 µm and a polydispersity index of 15%, indicating a uniform and stable dispersion. This formulation is successfully encapsulated into alginate beads, yielding uniform and spherical structures. SEM imaging shows smooth shell surfaces due to the incorporation of oil, further supported by FTIR analysis. Oil content analysis reveals that larger thin‐shelled beads retain the most oil (25.5%), demonstrating bead morphology influence. Mechanical and swelling tests also show that large, thin‐shelled beads provide superior pressure resistance and swelling capacity. These findings highlight the potential of emulsion‐filled core‐shell alginate beads for applications requiring structural integrity and controlled release.