Article
Polymer Science
Jumpei Kida, Daisuke Aoki, Hideyuki Otsuka
Summary: This study reports the mechanochemical strengthening of cross-linked elastomers using macrocyclic mechanophores containing a dynamic covalent disulfide bond, successfully imparting the polymers with self-strengthening functionality without the need for any additives such as monomers and modifiers.
Article
Polymer Science
Takuma Watabe, Daisuke Aoki, Hideyuki Otsuka
Summary: This research reports the mechanical and mechanochromic properties of a multinetwork elastomer with DFSN incorporated into its cross-linking points. By replacing a conventional cross-linker with a weaker one, the fracture toughness of the elastomer was improved. The study revealed the toughening mechanism of DFSN-containing multinetwork elastomers and demonstrated that the MN strategy can achieve high activation of mechanophores at a lower threshold strain.
Article
Nanoscience & Nanotechnology
Ashray Parameswar, Karan Dikshit, Sanli Movafaghi, Carson J. Bruns, Andrew P. Goodwin
Summary: The study focuses on the development of a mechanochemistry activated covalent conjugation (MACC) reaction to identify interfacial failure areas in soft hydrogels. The MACC reaction allows for selective tagging of wrinkle patterns and delamination areas at the edge of hydrogels, with an increase in cross-linker loading leading to higher delamination propagation and area fraction.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Yongliang Yang, Weijia Zhao, Hongyun Niu, Yaqi Cai
Summary: This research utilized the remaining aldehyde groups in a substoichiometric covalent organic framework to achieve precise construction of 2D/2D covalent organic nanosheets heterojunctions through mechanochemical methods, resulting in superior photoinduced charge generation and separation, and a significant enhancement in photocatalytic degradation efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Christoph Baumann, Maria Stratigaki, Silvia P. Centeno, Robert Gostl
Summary: The fracture of polymer materials is a complex multiscale process, and a new approach involving fluorescent molecular force probes has been developed to track intact and cleaved bonds, allowing for a quantitative description of the fracture processes in various materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Xiankai Jiang, Junjian Miao, Yi Gao
Summary: The spontaneous interconversion between covalent forces and noncovalent counterparts remains a mystery. This study discovered a transformation through halogen bonding using NI3 as a prototype and provided insights into the electronic structure basis and gradual transformation of this interconversion.
Article
Chemistry, Multidisciplinary
Yan Sun, Molly E. Mcfadden, Skylar K. Osler, Ross W. Barber, Maxwell J. Robb
Summary: In contrast to angular naphthopyrans, linear naphthopyrans are typically not photochromic. However, the incorporation of a polarizing dialkylamine substituent enables photochromic and mechanochromic behavior in polymers containing a novel linear naphthopyran motif.
Article
Chemistry, Physical
Michael Walter, Dominic Linsler, Tobias Koenig, Chris Gaebert, Stefan Reinicke, Michael Moseler, Leonhard Mayrhofer
Summary: Controlled formation and breaking of weak chemical bonds is a versatile method for modifying material properties. Anthracene [4+4] cycloadducts can be formed by light and opened by external forces. Theoretical study reveals that rupture of the [4+4] inter-anthracene bonds dominates the transition barriers, while other bonds only come into play at extremely large forces. Experimental results on [4+4]-linked anthracene polymers support the reversible re-formation of [4+4] cycloaddition bonds after mechanochemical bond breaking due to applied shear stress.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Vladimir Gorbachev, Alexandra Tsybizova, Larisa Miloglyadova, Peter Chen
Summary: This study evaluates the importance of London dispersion in moderately large organic molecules through experimental and theoretical calculations. The results show that London dispersion contributes small but significant effects on the molecular structure. However, when London dispersion operates against other weak noncovalent interactions, composite effects on the structure that are difficult to predict arise.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Yushuai Jiao, Yan Nan, Zhenhua Wu, Xueying Wang, Jiaxu Zhang, Boyu Zhang, Shouying Huang, Jiafu Shi
Summary: This study demonstrates a mechanochemical strategy to in situ embed enzymes into covalent organic networks (CONs), resulting in the synthesis of enzyme@CON NBHs. The prepared nanobiohybrids exhibit excellent chemical stability, catalytic activity, and resistance to harsh conditions due to the embedding of enzymes and the unique properties of CONs.
APPLIED MATERIALS TODAY
(2022)
Article
Polymer Science
Xiaoying Wang, Yifeng Cao, Yanling Peng, Lewen Wang, Wangmeng Hou, Yecheng Zhou, Yi Shi, Huahua Huang, Yongming Chen, Yuanchao Li
Summary: This novel mechanophore undergoes a chemical reaction upon mechanical activation, resulting in the generation of two new substances with different fluorescent colors. It also exhibits sensitivity to solvents, enabling dual-color mechanochromism.
Article
Chemistry, Multidisciplinary
Mengjiao Wu, Yiran Li, Wei Yuan, Guillaume De Bo, Yi Cao, Yulan Chen
Summary: The unique topological features of Piezo proteins inspired the development of mechanochromic polymers with unprecedented changes. By strategically placing spirolactam rings into aminobenzopyr-anoxanthene, a series of rhodamine-like mechanophores were created. The force-color relationship and reactivity of these mechanophores were investigated through experiments and calculations. Insights into tandem mechanochemical reactions and the design of isomeric mechanophores were gained.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Lucas de Azevedo Santos, Teodorico C. Ramalho, Trevor A. Hamlin, F. Matthias Bickelhaupt
Summary: Quantum chemical methods were used to analyze the nature and origin of directionality in pnictogen, chalcogen, and halogen bonds in F(m)Z·F- complexes. The results show that covalent interactions, in addition to electrostatic attraction, contribute significantly to the bond energy. Interestingly, despite electrostatic interactions favoring bending, all these bonds exhibit directionality, which contradicts the sigma-hole model. These findings are applicable to various complexes, including ClI·NH3, HClTe·NH3, and H2ClSb·NH3.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Polymer Science
Chunxia Zhu, Shuyu Pang, Zhaoxia Chen, Lehua Bi, Shuangfei Wang, Chen Liang, Chengrong Qin
Summary: Currently, the synthesis methods of crystalline porous materials often involve powder products, limiting their practical application and scale. In this study, a mechanochemical method was used to prepare TpPa-1-DANC composites, which showed potential for large-scale synthesis of COFs composites with diverse forms.
Article
Biochemistry & Molecular Biology
Monica Benito, Yannick Rosello, Miquel Barcelo-Oliver, Antonio Frontera, Elies Molins
Summary: This study reports three new halogen-bonded cocrystals prepared using a green and effective method, characterized by a variety of techniques, and computational methods were applied to study the relative importance of hydrogen versus halogen bonds in the crystal packing.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Robin Kueng, Anne Germann, Marcel Kruesmann, Louisa P. Niggemann, Jan Meisner, Matthias Karg, Robert Goestl, Bernd M. Schmidt
Summary: We have developed metal-organic cage-crosslinked polymer hydrogels by using bipyridine-functionalized polyethylene glycol chains. These hydrogels can encapsulate guest molecules and can be disassembled by ultrasound to release the cargo. The performance of the hydrogels was characterized by various techniques, including NMR, rheology, and SAXS experiments. The study also reveals the mechanism of cage-opening and demonstrates the enhanced drug-loading capacity of the hydrogels compared to non-crosslinked assemblies.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Yu Zhou, Silvia P. Centeno, Kuan Zhang, Lifei Zheng, Robert Goestl, Andreas Herrmann
Summary: This study reports the development of a series of ratiometric optical force probes (OFPs) based on fluorescent-protein-dye and protein-protein conjugates, and their incorporation into genetically engineered bio-glues. The OFPs efficiently modulate Forster resonance energy transfer upon force application, reporting on force-induced molecular alterations independent of concentration and fluorescence intensity. By fluorescence spectroscopy in solution and in the solid state, as well as fluorescence lifetime imaging microscopy, stress concentrations are visualized and adhesive and cohesive failure in the fracture zone is differentiated.
ADVANCED MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Jie Liu, Ying Zhang, Kim van Dongen, Chris Kennedy, Maaike J. G. Schotman, Patricia Marin San P. Roman, Cornelis Storm, Patricia Y. W. Dankers, Rint P. Sijbesma
Summary: Two synthetic supramolecular hydrogels, formed from bis-ureaamphiphilescontaining lactobionic acid (LBA) and maltobionic acid (MBA) bioactiveligands, are applied as cell culture matrices in vitro. They mimic essential features of the extracellular matrix, self-assembling into long supramolecular fibers that form hydrogels. The hydrogels exhibit different stiffnesses and excellent bioactive properties in hepatic cell cultures, promoting spheroid formation. These results highlight the potential of carbohydrate-functionalized hydrogels for liver tissue engineering.
Review
Chemistry, Physical
Yunfei Guo, Mikko Muuronen, Frederic Lucas, Rint P. P. Sijbesma, Zeljko Tomovic
Summary: The formation of isocyanurate via cyclotrimerization of isocyanates is widely reported to provide polyurethane materials with improved properties. The review summarizes catalysts for the cyclotrimerization of isocyanates, categorizing them into two main classes and providing detailed information on catalyst structures, reaction conditions, and trimerization efficiency. The review aims to stimulate the design of more efficient catalysts and further understanding of the trimerization mechanism.
Article
Polymer Science
Annelore Aerts, Stan F. S. P. Looijmans, Lambert C. A. van Breemen, Rint P. Sijbesma, Johan P. A. Heuts
Summary: Mechanofluorescent polymer probes were used to visualize stresses and bond scission in polystyrene and polycarbonate. Activation of polystyrene probes with a molar mass of 1.1 x 10(5) g center dot mol(-1) in solution reached 30% after 1 h of sonication, while shorter probes showed lower activation percentages. Friction tests on mechanophore-containing polystyrene and polycarbonate films revealed crack formation and activation patterns correlated with friction force, penetration depth, and mechanophore activation.
Article
Polymer Science
Ramkrishna Sarkar, Soumabrata Majumdar, Sierd Kuil, Jorg Mallens, Joost J. B. van Der Tol, Rint P. Sijbesma, Johan P. A. Heuts, Anja R. A. Palmans
Summary: Dynamic covalent networks (DCNs) utilize chemical bonds that can break and reform to allow for network reconfiguration under appropriate processing conditions. The addition of the acylsemicarbazide (ASC) motif, capable of hydrogen bonding and dynamic bond exchange, has expanded the repertoire of dynamic covalent bonds. This study demonstrates that the sulfur congener, thioacylsemicarbazide (TASC), also functions as a dynamic covalent bond, albeit with a slower exchange rate than ASC. DCNs based on siloxane incorporating ASC, TASC, or both, exhibit tunable relaxation dynamics that decrease with a higher proportion of TASC motifs. The reduction in stress relaxation is accompanied by a decrease in network creep, and can be controlled by adjusting the ASC/TASC ratio. These networks can be easily processed and dissolved using compression molding and excess hydrazide treatment, respectively. The ability to manipulate network properties and creep in dynamic covalent polymeric networks through minor modifications in dynamic bond structure provides a versatile synthetic approach that can be applied within a wide temperature range.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Mingjun Xuan, Jilin Fan, Vu Ngoc Khiem, Miancheng Zou, Kai-Oliver Brenske, Ahmed Mourran, Rostislav Vinokur, Lifei Zheng, Mikhail Itskov, Robert Goestl, Andreas Herrmann
Summary: Polymer mechanochemistry is a promising technology to convert mechanical energy into chemical functionality by breaking bonds. In this study, a microbubble system was used to accelerate the mechanochemical activation of disulfides, and optimization conditions were identified.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Siyang He, Simon Schog, Ying Chen, Yuxin Ji, Sinan Panitz, Walter Richtering, Robert Goestl
Summary: The serial connection of multiple stimuli-responses in polymer architectures enables the gating of functional material processes on demand. In this study, a photoswitchable diarylethene is used as a crosslinker in poly(N-vinylcaprolactam) microgels to induce a shift in volume phase-transition temperature (VPTT). By switching the microgels from the swollen to the collapsed state using light, their response to mechanical force can be controlled. This photoinduced mechanical cloaking system operates on a polymer topology level and is universally applicable.
ADVANCED MATERIALS
(2023)
Article
Polymer Science
Huiyi Zhang, Annemiek van Hertrooij, Tobias Schnitzer, Yinjun Chen, Soumabrata Majumdar, Rolf A. T. M. van Benthem, Rint P. Sijbesma, Johan P. A. Heuts
Summary: In dynamic polyamidenetworks, B4A units serve as a dynamic covalent cross-linker and supramolecular stacking motif simultaneously. The resulting materials have a higher rubbery plateau modulus compared to a reference network with suppressed supramolecular interactions. Branching polyamides with the same B4A dynamic motif form strong and reversible supramolecular networks through hydrogen bonding and stacking, while a nonstacking reference linker leads to a viscous liquid. Covalent cross-linking and stacking cooperatively contribute to the dynamics of the network, as confirmed by wide-angle X-ray scattering and variable-temperature infrared experiments.
Article
Polymer Science
Patrick Schara, Anna Maria Cristadoro, Rint P. Sijbesma, Zeljko Tomovic
Summary: Polyurethanes have a wide range of chemical and mechanical properties, and their recyclability can be greatly improved by introducing cleavable acetal bonds. This study presents a solvent-free synthesis of acetal-containing polyols using heterogeneous catalysts, and the obtained materials can be depolymerized under acidic and basic conditions with high recovery rates.
Article
Chemistry, Multidisciplinary
Emilia Izak-Nau, Louisa P. Niggemann, Robert Goestl
Summary: Research has shown that iron oxide nanoparticles larger than 15 nm react to alternating magnetic fields by undergoing Brownian relaxation, resulting in tumbling and shaking. This shaking motion is able to partially detach and cleave polymer coatings, leading to the release of cargo molecules. Unlike traditional hyperthermia applications, this heat-free release mechanism broadens the potential application space of magnetic nanoparticles.
Article
Polymer Science
Yunfei Guo, Julian Kleemann, Stefan Bokern, Andre Kamm, Rint P. Sijbesma, Zeljko Tomovic
Summary: To meet the increasing demands on thermal and mechanical properties of PU materials, polyisocyanurates (PIRs) have been introduced in PU materials as crosslinkers. A liquid PIR prepolymer with high PIR content was prepared and further reacted with long chain polyols and chain extenders to obtain PIR elastomers that exhibited good thermal stability and improved mechanical properties. This work demonstrates the potential industrial applications of the liquid PIR prepolymer.
Article
Polymer Science
Yunfei Guo, Sebastian Spicher, Anna Cristadoro, Peter Deglmann, Rint P. Sijbesma, Zeljko Tomovic
Summary: Poly(urethane imide)s (PUIs) with improved thermal properties and flame retardancy can be directly synthesized by the reaction of isocyanates with anhydrides to give aromatic imides. Experimental studies and quantum chemical calculations have investigated the mechanism of this reaction in the presence of water. The computational study has provided insights into the underlying mechanism and guided the development of a solvent-free synthetic method for industrial-scale production of PUIs.
