A design paradigm is demonstrated that enables new functional 3D printed materials made by fused filament fabrication (FFF) utilizing a thermally reversible dynamic covalent Diels-Alder reaction to dramatically improve both strength and toughness via self-healing mechanisms. To achieve this, we used as a mending agent a partially cross-linked terpolymer consisting of furan-maleimide Diels-Alder (fmDA) adducts that exhibit reversibility at temperatures typically used for FFF printing. When this mending agent is blended with commercially available polylactic acid (PLA) and printed, the resulting materials demonstrate an increase in the interfilament adhesion strength along the z-axis of up to 130%, with ultimate tensile strength increasing from 10 MPa in neat PLA to 24 MPa in fmDA-enhanced PLA. Toughness in the z-axis aligned prints increases by up to 460% from 0.05 MJ/m(3) for unmodified PLA to 0.28 MJ/m(3) for the remendable PLA. Importantly, it is demonstrated that a thermally reversible cross-linking paradigm based on the furan-maleimide Diels-Alder (fmDA) reaction can be more broadly applied to engineer property enhancements and remending abilities to a host of other 3D printable materials with superior mechanical properties.

We demonstrate that uniform mechanical properties can be achieved in 3D printed polymer blends by using a dynamic Diels–Alder reaction.

This commentary discusses current capabilities of vat photopolymerization, an additive manufacturing (AM) technique also known as VP, with recent advances in the literature, current challenges/limitations, and future outlook in novel materials design. Current trends and recent research advances are broadly discussed covering a spectrum of material classes such as performance, medicine, energy, and active materials in parallel to their importance in diverse technologies. Current challenges and limitations of VP are also discussed in terms of material properties, photodegradation, and material toxicity with directions in future material design to overcome these challenges. This commentary paper is intended to be of broad interest to both chemists and engineers actively involved in the AM field, in terms of future material design and processing for further development of VP-based AM technology.

Herein, we describe a 3D printable hydrogel that is capable of removing toxic metal pollutants from aqueous solution. To achieve this, shear‐thinning hydrogels were prepared by blending chitosan with diacrylated Pluronic F‐127 which allows for UV curing after printing. Several hydrogel compositions were tested for their ability to absorb common metal pollutants such as lead, copper, cadmium and mercury, as well as for their printability. These hydrogels displayed excellent metal adsorption with some examples capable of up to 95% metal removal within 30 min. We show that 3D printed hydrogel structures that would be difficult to fabricate by conventional manufacturing methods can adsorb metal ions significantly faster than solid objects, owing to their higher accessible surface areas. © 2019 Society of Chemical Industry

Alteration of the number of carbon atoms on the alkoxyphenyl substituent in naphthalene diimides results in tunable thermo-salient behavior.

Tellurite, the most soluble tellurium oxyanion, is extremely harmful for most microorganisms. Part of this toxicity is due to the generation of reactive oxygen species that in turn cause oxidative stress. However, the way in which tellurite interferes with cellular processes is not well understood to date. Looking for new cellular tellurite targets, we decided to evaluate the functioning of the electron transport chain in tellurite-exposed cells. In this communication we show that the E. coli ndh gene, encoding NDH-II dehydrogenase, is significantly induced in toxicant-exposed cells and that the enzyme displays tellurite-reducing activity that results in increased superoxide levels in vitro.

<div><div><div><p>Herein, we describe a 3D<br>printable hydrogel that is capable of<br>removing toxic metal pollutants from water<br>solutions. To achieve this, shear-thinning<br>hydrogels were prepared by blending<br>chitosan with diacrylated Pluronic F-127 (F127-DA) which allows for UV curing after printing. Several hydrogel compositions were tested for their ability to absorb common metal pollutants such as lead, copper, cadmium and mercury, as well as for their printability. These hydrogels displayed excellent metal adsorption with some examples capable of up to 95% metal removal within 30 min. We show that 3D printed hydrogel structures that would be difficult to fabricate by conventional manufacturing methods, can adsorb metal ions significantly faster than solid objects, owing to their higher accessible surface areas.</p></div></div></div>

<div><div><div><p>Herein, we describe a 3D<br>printable hydrogel that is capable of<br>removing toxic metal pollutants from water<br>solutions. To achieve this, shear-thinning<br>hydrogels were prepared by blending<br>chitosan with diacrylated Pluronic F-127 (F127-DA) which allows for UV curing after printing. Several hydrogel compositions were tested for their ability to absorb common metal pollutants such as lead, copper, cadmium and mercury, as well as for their printability. These hydrogels displayed excellent metal adsorption with some examples capable of up to 95% metal removal within 30 min. We show that 3D printed hydrogel structures that would be difficult to fabricate by conventional manufacturing methods, can adsorb metal ions significantly faster than solid objects, owing to their higher accessible surface areas.</p></div></div></div>