Molecular self-assembling block copolymers (BCPs) have shown promise as a next generation bottom-up lithography technology. However, a critical step in advancing this approach is the elimination of polymer dewetting due to bulk solvent nucleation and thermodynamically driven film rupture that can occur during the solvent vapor annealing process. We report on the pattern formation via phase segregation of spin coated diblock copolymer films through the investigation of annealing parameters in the limit of high solvent vapor saturation conditions that results in wafer-scale patterning without observing polymer dewetting defects. Specifically, the work addresses polymer dewetting in diblock copolymer nanodot templates through the use of a "neutral" functionalization layer and the development of a custom-built solvent vapor annealing chamber to precisely control saturation conditions. Furthermore, the long anneal times (4 h) using a standard static solvent vapor annealing procedure were reduced to ∼15-30 minutes with our dynamic solvent vapor annealing system for the high χ, cylindrical forming poly(styrene)-block-poly(4-vinyl-pyridine) [PS-b-P4VP] diblock copolymer system. We discuss the kinetic mechanism governing the phase segregation process that highlights the small processing window bounded by long phase segregation timescales (≳1 min) on one side and the initiation of polymer film dewetting on the other. These results demonstrate a key step towards realizing a high fidelity, low cost BCP patterning technique for large-scale "bottom-up" feature definition at nanometer length scales.
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http://dx.doi.org/10.1039/c6cp07633e | DOI Listing |
BMC Complement Med Ther
January 2025
Laser Research Centre, Faculty of Health Sciences, Doornfontein Campus, University of Johannesburg, Johannesburg, 2028, South Africa.
Background: Amongst all neoplastic diseases, breast cancer represents a major cause of death among the female population in developed and developing countries. Since alkaloid drugs are commonly used in chemotherapy to manage this disease, this study investigated the anti-proliferative effectiveness of alkaloid-rich fractions of Senna didymobotrya leaves only and with laser irradiation against MCF-7 breast cancer cells.
Method And Materials: A powdered sample of the plant leaves was extracted with 50% ethanol, filtered and their pH was adjusted with acid and base solution followed by partitioning with chloroform and ethyl acetate solvents.
Carbohydr Polym
March 2025
Department of Engineering and Technology, Universidade Federal Rural do Semi-Árido, Mossoró Campus, Mossoró 59625-900, Rio Grande do Norte, Brazil.
Alginate films were prepared from the brown seaweed Dictyota mertensii using glycerol as a plasticizer. The effects of extraction conditions-time, temperature, and NaCO concentration-on the optical, barrier, and mechanical properties of the films were investigated using a central composite design (CCD). ANOVA and F tests confirmed the models' statistical significance at p ≤ 0.
View Article and Find Full Text PDFVet Res Commun
January 2025
Faculty of Agriculture, University Farm, Utsunomiya University, Tochigi, 321-4415, Japan.
The purpose of this study was to improve the quality of frozen-thawed canine spermatozoa through the optimization of glycerol concentration (GC) and freezing rate in the semen freezing protocol. Ejaculates from nine dogs were diluted with an extender containing 0%, 1.5%, 3%, 6%, or 9% glycerol.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
State Key Laboratory of Fluid Power and Mechatronic Systems, Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, China.
Bioinspired supramolecular architectonics is attracting increasing interest due to their flexible organization and multifunctionality. However, state-of-the-art bioinspired architectonics generally take place in solvent-based circumstance, thus leading to achieving precise control over the self-assembly remains challenging. Moreover, the intrinsic difficulty of ordering the bio-organic self-assemblies into stable large-scale arrays in the liquid environment for engineering devices severely restricts their extensive applications.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
State Key Laboratory of Advanced Fiber Materials, Institute of Functional Materials, College of Materials Science and Engineering, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Shanghai Key Laboratory of Lightweight Composite, Donghua University, Shanghai 201620, China. Electronic address:
It remains a challenge for a simple and scalable method to fabricate ultrathin porous Janus membranes for stretchable on-skin electronics. Here, we propose a one-step droplet spreading phase separation strategy to prepare an ultrathin and easily collected Janus thermoplastic polyurethane (TPU) membrane within seconds. The metal-ion solvation structure mitigated migration kinetics to delay TPU solution demixing, promoting the further penetration of the coagulating solvent.
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