@article{FongChenWongetal., author = {Fong, Mun-Oon and Chen, Xiangping and Wong, Jie-Wei and Lok, Tow-Jie and Li, Siyang and Low, Jia Tee and Nordin, Nur Syahirra and Miao, Zhikun and Hu, Qiannan and Neffe, Axel T. and Wong, Tuck-Whye and Li, Tiefeng and Yang, Wei}, title = {Multifunctional Roles of Iron Oxide Nanoparticles in a Reversible Shape-Memory Composite}, series = {Advanced Functional Materials}, journal = {Advanced Functional Materials}, publisher = {Wiley}, issn = {1616-301X}, doi = {10.1002/adfm.202418409}, pages = {13}, abstract = {The utilization of functional fillers in the development of composite materials has come a long way since its advent to improve physical, chemical, or mechanical properties of the base material. However, the heterogenous roles contributed by a single type of filler remain uncommon in this field. Here the endowment of various modifications to a 1,8-octanediol/1,12-dodecanedioic acid/citric acid (OD/DDA/CA) matrix through the incorporation of iron oxide nanoparticles (IONPs) is reported. Owing to the relaxation and hysteresis loss behaviors of IONPs when exposed to an alternating magnetic field (AMF), the composites demonstrate a magnetothermal response. Similarly, the excitation and relaxation of electrons in IONPs under near-infrared light (NIR) enable photothermic-responsiveness. In combination, two findings nurtured an observed shape-memory effect when the samples are under actuation by these indirect stimuli, where a shape recovery ratio (≥98\%) and reversible strain (≤7\%) are recorded. Moreover, the catalytic role of IONPs aided transesterification in the covalent network, demonstrated by successful repeated cycles of shape reconfiguration of the samples. This work highlights the prospectives of multifunctional composite fillers in the exploration of bio-derived composite smart materials.}, language = {en} } @article{JamaludinNordinLietal., author = {Jamaludin, Farah Hidayah and Nordin, Nur Syahirra and Li, Xinge and Wong, Jie-Wei and Lim, Zhixian and Wang, Lei and Ma, Chunxin and Zhao, Qian and Wong, Tuck-Whye and Neffe, Axel T. and Li, Tiefeng}, title = {Recent Advances in the Field of Shape-Memory Polymer from Bio-Based Precursors: Review and Perspective}, series = {Polymer Reviews}, volume = {65}, journal = {Polymer Reviews}, number = {1}, publisher = {Informa UK Limited}, issn = {1558-3724}, doi = {10.1080/15583724.2024.2427827}, pages = {199 -- 249}, abstract = {Shape-memory polymers (SMPs) are predominantly derived from nonrenewable resources due to their low production cost, wide availability, and refined techniques for processing and tailoring SMP properties. However, the heavy reliance on these nonrenewable resources poses significant concerns regarding resource depletion and the long-term sustainability of the technology. As petroleum-based resources, which have traditionally fueled the polymer industry, become increasingly scarce, it is imperative to develop bio-based SMPs. This shift is essential not just for resource conservation but to ensure the continued viability and sustainability of SMP technology in the face of dwindling petroleum supplies. This review provides an overview of bio-based SMPs, which are synthesized from renewable precursors or through chemical variation and functionalization of biopolymers. The molecular mechanism and design strategy for the shape-memory effect (SME), syntheses, unique characteristics and shape-memory performance for these bio-based SMPs are covered. Furthermore, this review highlights novel insights and proposes promising directions for the development of sustainable SMPs with comparable performance to their nonrenewable counterparts. By focusing on bio-based alternatives, this work aims to motivate the exploration and advancement of next-generation sustainable SMPs.}, language = {en} } @misc{KruseBalkNeffeetal., author = {Kruse, Moritz and Balk, Maria and Neffe, Axel T. and Ben Khalifa, Noomane}, title = {Processing of reactive acrylic thermoplastic resin at elevated temperatures for rapid composite and fiber metal laminate manufacturing}, series = {Journal of Thermoplastic Composite Materials}, volume = {2025}, journal = {Journal of Thermoplastic Composite Materials}, number = {0 (0)}, publisher = {SAGE Publications}, issn = {0892-7057}, doi = {10.1177/08927057251314411}, pages = {1 -- 19}, abstract = {Thermoplastic polymers are increasingly being used as matrix materials for composites because they offer the advantage of recyclability and joinability over thermoset matrix systems. The polymerization kinetics and gas formation of different precursor mixtures of the liquid acrylic matrix system Elium® were investigated with different initiator contents and at different temperatures for accelerated processing of composites and fiber metal laminates. The mechanical and thermal properties of the resulting polymers showed no significant difference between the investigated parameters. However, the polymerization time was successfully reduced to under 15 minutes with higher temperatures and initiator contents in laminates with 1 mm thickness. In bulk polymerization and thicker laminates, the right parameters must be chosen to balance polymerization time and matrix heating to avoid gas formation leading to voids in the matrix. A combination of 75 wt\% Elium® 130 and 25 wt\% Elium® 190 with 1.25 wt\% peroxide initiator at 50 °C was found to be optimal for reducing gas formation while simultaneously accelerating the polymerization reaction in 3-5 mm thick layers.}, language = {en} } @misc{AlkhamisSaretiaSchwanzetal., author = {Alkhamis, Hanin and Saretia, Shivam and Schwanz, Susanne and Machatschek, Rainhard and Neffe, Axel T. and Polak-Kraśna, Katarzyna}, title = {Understanding the degradation and mechanical performance of hyperelastic polylactide copolymers through bulk and ultrathin film analysis correlation}, series = {Polymer Degradation and Stability}, volume = {235}, journal = {Polymer Degradation and Stability}, publisher = {Elsevier BV}, issn = {0141-3910}, doi = {10.1016/j.polymdegradstab.2025.111267}, pages = {1 -- 15}, abstract = {Appropriate degradation behavior of medical implants is essential, as early degradation of implanted biomaterials can lead to premature loss of mechanical integrity, causing complications such as inflammation and inadequate support during the critical healing period. Therefore, understanding the degradation of newly developed materials for in vivo applications is crucial. Here, we investigated the degradation behavior of blends from Poly[(L-lactide)-co-(ε-caprolactone)] and Poly(D-lactide) (PLLAcoCL/PDLA) in which stereocomplex crystals of the isotactic lactide sequences impart hyperelastic behavior. The PLLAcoCL/PDLA blends were studied through in vitro bulk degradation studies (in printed films and electrospun meshes) and in thin-films using the Langmuir technique. Chemical, thermal, and mechanical properties were assessed at different time-points, highlighting the effects of blends composition and stereocomplexation. The PLLAcoCL/PDLA polymer blend shows promising potential as a covering for expandable cardiovascular implants, offering high ultimate strains (up to >700 \%), elasticity, stability, and minimal mass loss during the crucial early healing period (4 weeks). Mechanical data suggest that specific blend ratios, particularly the 95:5 ratio in electrospun meshes, maintained mechanical integrity longer than others (E = 5.7 MPa at week 9), which was reflected in the mass loss of meshes (remaining mass = 67 wt\% at week 20). Lower PDLA content accelerated early degradation while enhancing oxidative resistance, whereas higher PDLA content slowed degradation but increased crystallinity. These findings emphasize how blend composition influences degradation rates, mechanical behavior, and stability. Findings highlight the role of composition in tailoring implant degradation and support predictive modeling for cardiovascular applications.}, language = {en} } @misc{MandluleLiuSchwanzetal., author = {Mandlule, Armando and Liu, Yue and Schwanz, Susanne and Pieper, Yvonne and Scharf, Heike and Iskhakova, Kamila and Concei{\c{c}}{\~a}o, Andre L. C. and Wieland, D. C. Florian and Zeller-Plumhoff, Berit and Toma, Francesca M. and Neffe, Axel T.}, title = {Correlative characterization of stereocomplex formation in blends of aliphatic polyester P(PCLₘ-b-PLLAₙ) multiblock-copolymers and PDLA}, series = {Materials advances}, journal = {Materials advances}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, issn = {2633-5409}, doi = {10.1039/d5ma00886g}, pages = {1 -- 26}, abstract = {In phase-separating multiblock copolymers it is a challenge to quantify the relationship between molecular structure and functional properties, yet this quantification is crucial for processing and applications. Here, we describe the molecular structure and phase behavior-properties relationships for a modular system of poly[(e-caprolactone)-b-poly(L-lactide)] multiblock copolymers with well-defined long/short block lengths and their blends with poly(D-lactide) (PDLA) of varying lengths. The formation of crystallite types and sizes as well as absolute and relative crystallinities of PCL, PLA homocrystallites (HC), and PLA stereocrystallites (SC) were studied by DSC and WAXS, and visualized by TEM, POM, and AFM. We reveal that SC formation occurs in blends containing a ratio between 1 : 1 and 1 : 4 ratio of PDLA and PLLA. In systems with much longer PCL than PLLA sequence length (113 : 18), SC formation is inhibited. Blend crystallinity was highest for a medium PDLA length. SC formation is preferred over HC formation, and SCs act as nucleation points for PCL crystallization. In our work the segment length had a trend to correlate with crystallite sizes. Tensile strength (from 0.5 to 8 MPa) and elongation at break (from 10\% to >750\% at room temperature) could be increased simultaneously by allowing SC formation, which in the studied blends correlated with low overall crystallinity. Our study shows strategic polymer synthesis and blending for the precise control of stereocomplex formation and fine-tuning in high-performance PLA-based materials. These findings support the knowledge-based choice of blend composition and segment length to tailor versatile materials with tunable mechanical and thermal properties.}, language = {en} } @misc{LiLokNgoetal., author = {Li, Siyang and Lok, Tow-Jie and Ngo, Shi-Han and Xue, Yaoting and Miao, Zhikun and Feng, Tao and Wang, Lei and Wong, Jie-Wei and Low, Jiatee and Lim, Kai-Yi and Woon, Min-Rou and Neffe, Axel T. and Wong, Tuck-Whye and Li, Tiefeng and Yang, Xuxu and Yang, Wei}, title = {A water-recyclable, robust, and self-healing sugar-based supramolecular network enabled by Maillard-analogous initialization of polymerization}, series = {Materials horizons}, volume = {13}, journal = {Materials horizons}, number = {1}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, issn = {2051-6347}, doi = {10.1039/D5MH01828E}, pages = {219 -- 232}, abstract = {Crosslinked functional polymers exhibit exceptional mechanical and chemical properties critical for applications spanning biomedical engineering, advanced adhesives, and self-healing materials. However, challenges in recycling, either due to irreversible crosslinks or, in the case of covalent adaptable networks (CANs), limited solid-state plasticity that typically requires catalysts, significantly restrict sustainability. To address these limitations, we present a novel water-mediated polymerization strategy inspired by the radical-generating mechanism of the Maillard reaction, utilizing maltose as both an initiator and a functional side group in a simple, catalyst-free, aqueous reaction with acrylamide (AAm). This mild, one-pot reaction occurs below 100 °C, forming adaptively functionalized supramolecular networks (AFSNs) that form supramolecular networks through hydrogen bonding and display dynamic imine linkages to the maltose side chains supporting self-healing and re-shaping. These elastomers are characterized by impressive mechanical strength (up to 5 MPa tensile strength), high elongation (up to 1000\%), notable fracture energy (36 kJ m-2), robust adhesive performance (up to 4.8 MPa), and rapid self-healing capability at room temperature. Crucially, the elastomer's supramolecular network can be fully and repeatedly dissolved and reprocessed using only water, preserving mechanical integrity without chemical degradation. This sustainable approach provides a practical solution for synthesizing and recycling high-performance crosslinked materials while eliminating environmental hazards, guiding the future development of green polymer chemistry and functional material design.}, language = {en} } @misc{RachevaBasaloLouridoGurdaletal., author = {Racheva, Miroslava and Basalo Lourido, Javier and Gurdal, Enise Ece and Herbst, Martin and Bayar, Seyhmus and Radzik, Daniela and B{\"a}hr, Elen and Zwies, Constanze and Neffe, Axel T. and Pietzsch, Markus and Lendlein, Andreas and Wischke, Christian}, title = {Tyrosinase cross-linked PEG hydrogels with DAT and DATT as artificial substrates : design, structure, and functions}, series = {Biomacromolecules}, volume = {27}, journal = {Biomacromolecules}, number = {2}, publisher = {American Chemical Society (ACS)}, address = {Washington, DC}, issn = {1525-7797}, doi = {10.1021/acs.biomac.5c01929}, pages = {1317 -- 1336}, abstract = {Enzymes such as oxidases are sustainable tools for hydrogel synthesis, but complex competing reactions have limited the mechanistic understanding and biomedical applications of these materials. Guided by molecular docking and MM-GBSA calculations, we identified two artificial substrates, desaminotyrosine (DAT) and desaminotyrosyltyrosine (DATT), that were experimentally more efficiently converted by mushroom tyrosinase (mTyr) than the natural substrate tyrosine. These substrates were used to synthesize hydrogels from DAT/DATT-functionalized star-shaped oligoethylene glycol (sOEG). Model reactions elucidated the chemical nature and functionality of the hydrogel netpoints. Material properties were systematically investigated depending on sOEG molecular weight (5, 10, 20 kDa), substrate type, and mTyr concentration. Functional mesh sizes and controlled release functions were investigated with fluorescent dextrans (4-500 kDa) and heparin. Cell culture studies with L929 fibroblasts and THP-1 monocytes suggested inertness of the material. These findings provide fundamental insight into mTyr-catalyzed hydrogel formation and support further exploration for in situ hydrogel synthesis.}, language = {en} } @misc{BalkSchroeterdaConceicaoetal., author = {Balk, Maria and Schroeter, Michael and da Concei{\c{c}}{\~a}o, Eduardo and Schneider, Nicole and Heuchel, Matthias and Pieper, Yvonne and Schwanz, Susanne and Khani, Navid and Alkhamis, Hanin and Polak-Kraśna, Katarzyna and Neffe, Axel T. and Toma, Francesca M.}, title = {Room-temperature, aqueous-based 3D printing of fully recyclable wood-like Inks from upcycled lignin}, series = {ACS sustainable chemistry \& engineering}, journal = {ACS sustainable chemistry \& engineering}, publisher = {American Chemical Society (ACS)}, address = {Washington, DC}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.5c07974}, pages = {A -- L}, abstract = {Despite growing interest in sustainable additive manufacturing, most 3D printing inks rely on fossil-based polymers, require postprocessing, or lack recyclability. Here, we report a fully recyclable, water-based ink composed of 70 wt \% lignosulfonate, an abundant industrial byproduct, formulated for high-resolution 3D printing via direct ink writing at room temperature. This ink eliminates the need for chemical cross-linkers, organic solvents, or energy-intensive postcuring. Its tailored rheology, governed by reversible hydrogen bonding and hydrophobic interactions, ensures excellent shape fidelity and print stability. Mechanical properties are tunable via glycerol content, and shape stability of up to 200 °C can be achieved. The material is fully recyclable by simple rehydration without a loss in performance. This sustainable and scalable formulation bridges biomass valorization, functional prototyping, and circular manufacturing on a unified platform.}, language = {en} }