Hydrophobically modified silica nanolaces-armored water-in-oil pickering emulsions with enhanced interfacial attachment energy

Preparation of hyperbranched hydrophobic nano-silica and its superior needling-effect in PDMS defoam agent

Hydrophobic nano silica powder is a kind of important synergist to silicone defoaming agents. The large pore volume and branched chain conformation of silica nanoparticles present superior effects on defoaming properties. However, silica nanoparticles synthesized by liquid phase easily aggregate and pore collapse because of their high surface activity and polarity, leading to poorer dispersity and limited practicability. In this paper, a novel hydrophobic silica with a hyperbranched structure was designed through in-situ modifying method with hexamethyldisilazane (HMDS) and polydimethylsiloxane (PDMS) in the liquid phase. The trimethylsilanol generated by HMDS hydrolysis reacts quickly with the highly active hydroxyl groups on the silica, causing the surface properties of the nanoparticles to transform from polar to non-polar properties. The steric hindrance of the trimethyl silicon and the reduction of the surface polarity effectively prevent silica pores from collapsing and maintain the macropore structures to realize the hyperbranched silica. At the same time, the -Si (CH3)2- from PDMS endowed the hyperbranched silica with excellent hydrophobicity. When applied in the defoaming agent, the hydrophobicity of silica contributes to dewetting the foams, and the hyperbranched spatial structures play an enhanced needling effect. Therefore, this hydrophobic hyperbranched silica exhibited a surprising defoaming effect, which significantly reduced the defoaming time from 464.4 s to less than 2 s, superior to commercial defoaming silica (155.3 s). The defoaming efficiency reached 100 % within 2 s of the end of the shaking, and the defoamer antifoaming ability was improved to reach 27.5 min, which was 77 % higher than that of commercial defoamer.

Bacterial cellulose in cosmetic innovation: A review

Bacterial cellulose (BC) emerges as a versatile biomaterial with a myriad of industrial applications, particularly within the cosmetics sector. The absence of hemicellulose, lignin, and pectin in its pure cellulose structure enables favorable interactions with both hydrophilic and hydrophobic biopolymers. This enhances compatibility with active ingredients commonly employed in cosmetics, such as antioxidants, vitamins, and botanical extracts. Recent progress in BC-based materials, which encompasses membranes, films, gels, nanocrystals, and nanofibers, highlights its significant potential in cosmetics. In this context, BC not only serves as a carrier for active ingredients but also plays a crucial role as a structural agent in formulations. The sustainability of BC production and processing is a central focus, highlighting the need for innovative approaches to strengthen scalability and cost-effectiveness. Future research endeavors, including the exploration of novel cultivation strategies and functionalization techniques, aim to maximize BC's therapeutic potential while broadening its scope in personalized skincare regimes. Therefore, this review emphasizes the crucial contribution of BC to the cosmetics sector, underlining its role in fostering innovation, sustainability, and ethical skincare practices. By integrating recent research findings and industry trends, this review proposes a fresh approach to advancing both skincare science and environmental responsibility in the cosmetics industry.

Ultralight, Robust, Thermal Insulating Silica Nanolace Aerogels Derived from Pickering Emulsion Templates

Synthesis of silica aerogel insulators with ultralight weight and strong mechanical properties using a simplified technique remains challenging for functional soft materials. This study introduces a promising method for the fabrication of mechanically reinforced ultralight silica aerogels by employing attractive silica nanolace (ASNLs)-armored Pickering emulsion templates. For this, silica nanolaces (SiNLs) are fabricated by surrounding a cellulose nanofiber with necklace-shaped silica nanospheres. In order to achieve amphiphilicity, which is crucial for the stabilization of oil-in-water Pickering emulsions, hydrophobic alkyl chains and hydrophilic amine groups are grafted onto the surface of SiNLs by silica coupling reactions. Freeze-drying of ASNLs-armored Pickering emulsions has established a new type of aerogel system. The ASNLs-supported mesoporous aerogel shows 3-fold greater compressive strength, 4-fold reduced heat transfer, and a swift heat dissipation profile compared to that of the bare ASNL aerogel. Additionally, the ASNL aerogel achieves an ultralow density of 8 mg cm-3, attributed to the pore architecture generated from closely jammed emulsion drops. These results show the potential of the ASNL aerogel system, which is ultralight, mechanically stable, and thermally insulating and could be used in building services, energy-saving technologies, and the aerospace industry.