Jimenez, Andrew M.; Krauskopf, Alejandro A.; Pérez-Camargo, Ricardo A.; Zhao, Dan; Pribyl, Julia; Jestin, Jacques; Benicewicz, Brian C.; Müller, Alejandro J.; Kumar, Sanat K.
Effects of Hairy Nanoparticles on Polymer Crystallization Kinetics
We previously showed that nanoparticles (NPs) could be ordered into structures by using the growth rate of polymer crystals as the control variable. In particular, for slow enough spherulitic growth fronts, the NPs grafted with amorphous polymer chains are selectively moved into the interlamellar, interfibrillar, and interspherulitic zones of a…
A facile approach to thermomechanically enhanced fatty acid-containing bioplastics using metalligand coordination
Lamm, Meghan E.; Song, Lingzhi; Wang, Zhongkai; Lamm, Benjamin; Fu, Lin; Tang, Chuanbing
Biomass-based polymers show promise for the mitigation of environmental issues associated with petroleum-derived commodity polymers; however, due to poor entanglement, many of these polymers typically lack mechanical strength and toughness. Herein, we report a facile approach to utilizing metalligand coordination to create physical crosslinking, and thus chain entanglements for plant…
Nanofiller Dispersion, Morphology, Mechanical Behavior, and Electrical Properties of Nanostructured Styrene-Butadiene-Based Triblock Copolymer/CNT Composites
Staudinger, Ulrike; Satapathy, Bhabani K.; Jehnichen, Dieter
A nanostructured linear triblock copolymer based on styrene and butadiene with lamellar morphology is filled with multiwalled carbon nanotubes (MWCNTs) of up to 1 wt% by melt compounding. This study deals with the dispersability of the MWCNTs within the nanostructured matrix and its consequent impact on block copolymer (BCP) morphology,…
Tough Ordered Mesoporous Elastomeric Biomaterials Formed at Ambient Conditions
Rajasekharan, Anand K.; Gyllensten, Christoffer; Blomstrand, Edvin; Liebi, Marianne; Andersson, Martin
Synthetic dry elastomers are randomly cross-linked polymeric networks with isotropic and unordered higher-level structural features. However, their growing use as soft-tissue biomaterials has demanded the need for an ordered and anisotropic nano-micro (or) mesoarchitecture, which is crucial for imparting specific properties such as hierarchical toughening, anisotropic mechanics, sustained drug
Revisiting the Dissolution of Cellulose in NaOH as “Seen” by X-rays
Martin-Bertelsen, Birte; Andersson, Erika; Köhnke, Tobias; Hedlund, Artur; Stigsson, Lars; Olsson, Ulf
Cotton production is reaching a global limit, leading to a growing demand for bio-based textile fibers produced by other means. Textile fibers based on regenerated cellulose from wood holds great potential, but in order to produce fibers, the components need to be dissolved in suitable solvents. Furthermore, the dissolution process…
Facile treatment to fine-tune cellulose crystals in cellulose-silk biocomposites through hydrogen peroxide
Love, Stacy A.; Popov, Elizabeth; Rybacki, Karleena; Hu, Xiao; Salas-de la Cruz, David
The modulation of structural fibrous protein and polysaccharide biopolymers for the design of biomaterials is still relatively challenging due to the non-trivial nature of the transformation from a biopolymer's native state to a more usable form. To gain insight into the nature of the molecular interaction between silk and cellulose…
Rheological modifiers based on supramolecular block copolymers: From weak associations to interconnected micelles
Goldansaz, Hadi; Jangizehi, Amir; Nikravan, Goolia; Verkinderen, Olivier; Goderis, Bart; Ghaffarian, Seyed Reza; van Ruymbeke, Evelyne; Ahmadi, Mostafa
The rheological spectra of poly(n-butyl acrylate) in the presence of a series of P(nBA-b-HEMA) rheology modifiers show a two-step relaxation process originating from the PnBA matrix and the self-assemblies. The HEMA segments are further grafted with strong, hydrogen bonding UPy groups, which both magnifies and slows down the relaxation of…
OrderOrder Phase Transitions Induced by Supercritical Carbon Dioxide in Triblock Copolymer Thin Films
Abate, Anabella A.; Vu, Giang Thi; Piqueras, Cristian M.; del Barrio, María Cecilia; Gómez, Leopoldo R.; Catalini, Gabriel; Schmid, Friederike; Vega, Daniel A.
We study the influence of supercritical carbon dioxide (scCO2) on the phase behavior of a cylinder-forming polystyrene-block-polybutadiene-b-polystyrene triblock copolymer thin film. Solvent annealing with scCO2 can produce patterns with long-range order but these structures become unstable for thin films with small thicknesses. These results are in good agreement with self-consistent…
CO2-Triggered and temperature-switchable crystallization-driven self-assembly of a semicrystalline block copolymer in aqueous medium
Zhu, Rui; Luo, Xinjie; Feng, Yujun; Billon, Laurent
The synthesis of a semicrystalline block copolymer comprising a hydrophilic poly(acrylic acid) (PAA) pure block and an amphiphilic poly(acrylic acid)-r-poly(octadecyl acrylate) (PAA-r-PODA) random block by nitroxide-mediated polymerization (NMP) is reported. The aggregation behavior of the copolymer in aqueous medium was studied by using a MicroCal VP differential scanning calorimeter (VP-DSC)
Determination of the Critical Size of Secondary Nuclei on the Lateral Growth Front of Lamellar Polymer Crystals
Zhang, Shujing; Han, Jiarui; Gao, Yang; Guo, Baohua; Reiter, Günter; Xu, Jun
Nucleation is the rate-limiting first step of crystallization. The energy barrier related to form the critical nucleus predominantly affects the nucleation rate. Determination of the size of the critical nucleus is a key for understanding the mechanism of nucleation and allows testing theories. However, it has been a great challenge…