Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Béla tér 1, Szeged, H-6720, Hungary.
Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged, H-6720, Hungary.
Chemphyschem. 2021 Mar 3;22(5):488-492. doi: 10.1002/cphc.202000952. Epub 2021 Jan 27.
Spatial structures break their symmetry under the influence of shear stress arising from fluid flow. Here, we present surface instabilities appearing on chitosan tubes when an acidic solution of chitosan with various molecular weight is injected into a pool of sodium hydroxide solution. At slow flow rates wrinkle-to-fold transition takes place along the direction of the flow yielding a banded structure. For greater injection rates we observe coexisting modes of wrinkles and folds which are stabilized to periodic wrinkles when the alkaline concentration is increased. The instabilities are characterized by the scaling laws of the pattern wavelength and amplitude with the tube characteristics. Our experimental adaptation of mechanical instabilities provides a new in situ method to create soft biomaterials with the desired surface morphology without the use of any prefabricated templates.
在流体流动产生的剪切应力的影响下，空间结构会打破其对称性。在这里，我们展示了壳聚糖管表面出现的不稳定性，当不同分子量的壳聚糖酸性溶液注入到氢氧化钠溶液池中时。在较慢的流速下，沿着流动方向发生皱折到褶皱的转变，产生带状结构。对于更大的注射速率，当碱性浓度增加时，我们观察到褶皱和褶皱的共存模式，这些模式稳定到周期性褶皱。不稳定性的特征是图案波长和振幅与管特性的标度律。我们对机械不稳定性的实验适应性提供了一种新的原位方法，无需使用任何预制模板即可创建具有所需表面形态的软生物材料。
