Graphical abstract

Additive manufacture of lightly crosslinked semicrystalline thiol-enes for enhanced mechanical performance.

Feb. 26, 2020

Photopolymerizable semicrystalline thermoplastics resulting from thiol-ene polymerizations were formed via fast polymerizations and achieved excellent mechanical properties. These materials have been shown to produce materials desirable for additive manufacturing (3D printing), especially for recyclable printing and investment casting. However, while well-resolved prints were previously achieved with the thiol-ene thermoplastics, the...

 Percent flocculation (%) as a function of flocculant dose (ppm) and flocculant molecular weight (g/mol) for cationic homopolymer flocculant (H-CAT) applied to a homogenous suspension of negatively-charged silica microparticles.

Flocculation behavior and mechanisms of block copolymer architectures on silica microparticle and Chlorella vulgaris systems

Feb. 26, 2020

Hypothesis Flocculation performance using polyelectrolytes is influenced by critical design parameters including molecular weight, amount and sign of the ionic charge, and polymer architecture. It is expected that systematic variation of these characteristics will impact not only flocculation efficiency (FE) achieved but that charge density and architecture, specifically, can alter...

Graphical abstract

Reaction Environment Effect on the Kinetics of Radical Thiol–Ene Polymerizations in the Presence of Amines and Thiolate Anions

Jan. 31, 2020

Because of facile implementation, quantitative conversions, and an insensitivity to oxygen, water, and most organic functional groups, radical-mediated thiol–ene coupling (TEC) reactions have emerged as a valuable tool in macromolecule synthesis. It was recently demonstrated that the kinetics and conversions of thiyl radical-mediated reactions are adversely affected in the presence...

DMA output of the tan(δ) (left) and storage modulus (right)

Combined Dynamic Network and Filler Interface Approach for Improved Adhesion and Toughness in Pressure-Sensitive Adhesives

Dec. 31, 2019

Of importance for adhesive materials, particularly pressure-sensitive adhesive (PSA) systems, is the ability to increase bulk toughness without reduction of adhesion. Previous approaches for increasing PSA durability sacrifice permanent cross-linking or adhesive potential, limiting performance. In this work, covalent adaptable networks (CANs) derived from thiol-thioester exchange (TTE) are utilized as...

Mechanisms for thiol–thioester exchange (TTE) and Reversible addition-fragmentation chain transfer (RAFT) as examples for dynamic covalent chemistries (DCCs).

Dynamic covalent chemistry (DCC) in dental restorative materials: Implementation of a DCC-based adaptive interface (AI) at the resin–filler interface for improved performance

Dec. 30, 2019

Objective Dental restorative composites have been extensively studied with a goal to improve material performance. However, stress induced microcracks from polymerization shrinkage, thermal and other stresses along with the low fracture toughness of methacrylate-based composites remain significant problems. Herein, the study focuses on applying a dynamic covalent chemistry (DCC)-based adaptive...

 Polymerization kinetics of thiol-Michael composites and BisGMA/TEGDMA

Vinyl sulfonamide based thermosetting composites via thiol-Michael polymerization

Dec. 30, 2019

Objective To assess the performance of thiol Michael photocurable composites based on ester-free thiols and vinyl sulfonamides of varying monomer structures and varied filler loadings and to contrast the properties of the prototype composites with conventional BisGMA-TEGDMA methacrylate composite. Methods Synthetic divinyl sulfonamides and ester-free tetrafunctional thiol monomers were utilized...

Chemical structures and acronyms of hydrazides and Michael acceptors employed as monomers in this study.

Catalyst-free, aza-Michael polymerization of hydrazides: polymerizability, kinetics, and mechanistic origin of an α-effect

Dec. 3, 2019

Despite the powerful nature of the aza-Michael reaction for generating C–N linkages and bioactive moieties, the bis-Michael addition of 1° amines remains ineffective for the synthesis of functional, step-growth polymers due to the drastic reduction in reactivity of the resulting 2° amine mono-addition adduct. In this study, a wide range...

S-7Figure S3 Image of liposome after addition of ammonium solution and 48h incubation under 50 °C(Rhdamine-DHPE as fluorescence dye)

Hybrid Cerasomes Composed of Phosphatidylcholines and Silica Networks for the Construction of Vesicular Materials with Functionalized Shells

Dec. 3, 2019

A phosphatidylcholine-based cerasome (PC-cerasome) was prepared by a combination of a copper-catalyzed azide alkyne cyclo-addition (CuAAC) reaction and a sol–gel condensation process. In a 2 wt % urea aqueous solution, azide precursors containing a triethoxysilane group (TEOS) were coupled with an alkyne lysolipid (AL) through a CuAAC reaction to generate...

Shapeshifter material

Shape-shifting material can morph, reverse itself using heat, light

Aug. 24, 2018

A new material developed by CU Boulder engineers can transform into complex, pre-programmed shapes via light and temperature stimuli, allowing a literal square peg to morph and fit into a round hole before fully reverting to its original form. The controllable shape-shifting material, described today in the journal Science Advances...