Fabrication of Soft Transparent Patient-Specific Vascular Models with Stereolithographic 3D printing and Thiol-Based Photopolymerizable Coatings

An ideal vascular phantom should be anatomically accurate, have mechanical properties as close as possible to the tissue, and be sufficiently transparent for ease of visualization. However, materials that enable the convergence of these characteristics have remained elusive. The fabrication of patient-specific vascular phantoms with high anatomical fidelity, optical transparency, and mechanical properties close to those of vascular tissue is reported. These final properties are achieved by 3D printing patient-specific vascular models with commercial elastomeric acrylic-based resins before coating them with thiol-based photopolymerizable resins. Ternary thiol-ene-acrylate chemistry is found optimal. A PETMP/allyl glycerol ether (AGE)/polyethylene glycol diacrylate (PEGDA) coating with a 30/70% AGE/PEGDA ratio applied on a flexible resin yielded elastic modulus, UTS, and elongation of 3.41 MPa, 1.76 MPa, and 63.2%, respectively, in range with the human aortic wall. The PETMP/AGE/PEGDA coating doubled the optical transmission from 40% to 80%, approaching 88% of the benchmark silicone-based elastomer. Higher transparency correlates with a decrease in surface roughness from 2000 to 90 nm after coating. Coated 3D-printed anatomical replicas are showcased for pre-procedural planning and medical training with good radio-opacity and echogenicity. Thiol-click chemistry coatings, as a surface treatment for elastomeric stereolithographic 3D-printed objects, address inherent limitations of photopolymer-based additive manufacturing.

Facile Fabrication of Polymer Electrolytes with Branched Structure via Deep Eutectic Electrolyte-Enabled In Situ Polymerizations

The demand for higher energy density in energy storage devices drives further research on lithium metal batteries (LMBs) because of the high theoretical capacity and low voltage of lithium metal anode. Polymer electrolytes (PEs) exhibit obvious advantages in combating volatilization and leakage compared with liquid electrolytes, which improves the safety of LMBs. However, it is still difficult to construct PEs with a stable electrolyte-electrode interface for high-performance and long-term life LMBs. Herein, the gel polymer electrolyte (GPE-SL) containing deep eutectic electrolyte (DEE) and branchlike polymer skeleton are designed and prepared by the DEE-induced in situ cationic and radical polymerizations. The DEE provides a smooth Li+ migration pathway to ensure the electrochemical properties, and the multibrominated polymer matrix formed in situ enables a LiBr-rich solid electrolyte interphase (SEI) layer on lithium metal anode and prolongs the life span of LMBs. Hence, the Li|GPE-SL|LiFePO4 battery displays an excellent cycling stability with 84% capacity retention after 1200 cycles at 1C. This simple deep eutectic electrolyte-induced polymerization method provides a promising direction for high-performance LMBs with improved anode-electrolyte compatibility through the construction of a stable SEI layer in situ.

Organosulfur Materials for Rechargeable Batteries: Structure, Mechanism, and Application

Lithium-ion batteries have received significant attention over the last decades due to the wide application of portable electronics and increasing deployment of electric vehicles. In order to further enhance the performance of the batteries and overcome the capacity limitations of inorganic electrode materials, it is imperative to explore new cathode and functional materials for rechargeable lithium batteries. Organosulfur materials containing sulfur-sulfur bonds as a kind of promising organic electrode materials have the advantages of high capacities, abundant resources, tunable structures, and environmental benignity. In addition, organosulfur materials have been widely used in almost every aspect of rechargeable batteries because of their multiple functionalities. This review aims to provide a comprehensive overview on the development of organosulfur materials including the synthesis and application as cathode materials, electrolyte additives, electrolytes, binders, active materials in lithium redox flow batteries, and other metal battery systems. We also give an in-depth analysis of structure-property-performance relationship of organosulfur materials, and guidance for the future development of organosulfur materials for next generation rechargeable lithium batteries and beyond.

Gel-polymer electrolytes based on polyurethane ionomers for lithium power sources

Polyurethanes based on the aminoethers of ortho-phosphoric acid and polyisocyanates of an aliphatic nature were studied as a substrate for the preparation of new polymer electrolyte. The conductivity of polyurethane ionomer samples obtained using the optimal amount of aliphatic polyisocyanates and after keeping them in a 1 M LiBF₄ solution in γ-butyrolactone reaches 0.62 mS cm⁻¹. It has been established that the transport of positively charged ions through the polymer matrix is due to the formation of clusters of phosphate ions and their association into the conducting channels. The introduction of carboxylate ions into the conducting channels by modifying the aminoethers of ortho-phosphoric acid with phthalic anhydride leads to an increase in their size and rise in the mobility of cations. As a result, the conductivity of polyurethane gel electrolytes increased to 2.1 mS cm⁻¹.

Polyurethanes based on the aminoethers of ortho-phosphoric acid and polyisocyanates of an aliphatic nature were studied as a substrate for the preparation of a new polymer electrolyte.

Covalently cross-linked polymer stabilized electrolytes with self-healing performance via boronic ester bonds

This article reported a facile fabrication of self-healing solid polymer electrolytes via boronic ester bonds.