Consequences of Ultra-Violet Irradiation on the Mechanical Properties of Spider Silk

AbstractSpider silk attracts researchers from the most diverse fields, such as material science or medicine. However, still little is known about silk aside from its molecular structure and material strength. Spiders produce many different silks and even join several silk types to one functional unit. In cribellate spiders, a complex multi-fibre system with up to six different silks affects the adherence to the prey. The assembly of these cribellate capture threads influences the mechanical properties as each fibre type absorbs forces specifically. For the interplay of fibres, spinnerets have to move spatially and come into contact with each other at specific points in time. However, spinneret kinematics are not well described though highly sophisticated movements are performed which are in no way inferior to the movements of other flexible appendages. We describe here the kinematics for the spinnerets involved in the cribellate spinning process of the grey house spider, Badumna longinqua, as an example of spinneret kinematics in general. With this information, we set a basis for understanding spinneret kinematics in other spinning processes of spiders and additionally provide inspiration for biomimetic multiple fibre spinning.

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Dynamic Mechanical Analysis of Bio-Based and Synthetic Petroleum Based Polymer Foams with Powder Type Organic Filler at Prolonged Ultra-Violet Exposure

Emerging Advances in Integrated Technology ◽

10.30880/emait.2020.01.01.006 ◽

2020 ◽

Vol 01 (01) ◽

Author(s):

M A Zulhakimie ◽

◽

Anika Zafiah M. Rus ◽

N S S Sulong ◽

A Syah Z A ◽

...

Keyword(s):

Mechanical Properties ◽

Epoxy Polymer ◽

Loss Modulus ◽

Ultra Violet ◽

Mechanical Analysis ◽

Uv Exposure ◽

Polymer Foams ◽

Polymer Foam ◽

Powder Filler ◽

Tan Δ

Wood powder filler applied to the bio-based and epoxy polymer foams has the potential to reinforce the polymer foam structure. The 'Meranti' wood filler type was used as the filler in this analysis. In order to observe the pore size of each sample when exposed to different hours of UV exposure using optical microscopy (OM), this study was made.This analysis was conducted to compare the mechanical properties of each sample with different filler ratios of 0 wt%, 5 wt%, 10 wt%, 15wt% and 20 wt% at different UV exposure hours, which is 0 hour to 6000 hours with a 2000 hour rapid increase. Using the DMA Q800 TA unit, the mechanical properties were studied. In order to obtain the product of their mechanical properties, samples having a scale of 40 x 10 x 5 mm were clamped into the machine. The results will show the value of tan δ, loss modulus and storage modulus from the DMA test.The tan δ value shows that the high tanδvalue will be produced by the higher ratio filler. In contrast to bio-based polymer foams, epoxy polymer foams with powder fillers have the highest tan δ value. It shows that the higher filler ratio can be reported with the lower tan δ value. As the filler ratio filler in the polymer foams increased, the consequence of storage and loss modulus was found to increase. The greater the modulus of loss and the modulus of storage, the lower the temperature. As energy is lost as heat during UV irradiation exposure, bio-based polymer foams with a high powder filler ratio can dissipate more energy.

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Relationships between supercontraction and mechanical properties of spider silk

Nature Materials ◽

10.1038/nmat1534 ◽

2005 ◽

Vol 4 (12) ◽

pp. 901-905 ◽

Cited By ~ 192

Author(s):

Yi Liu ◽

Zhengzhong Shao ◽

Fritz Vollrath

Keyword(s):

Mechanical Properties ◽

Spider Silk

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Presence of β-Turn Structure in Recombinant Spider Silk Dissolved in Formic Acid Revealed with NMR

Molecules ◽

10.3390/molecules27020511 ◽

2022 ◽

Vol 27 (2) ◽

pp. 511

Author(s):

Yu Suzuki ◽

Takanori Higashi ◽

Takahiro Yamamoto ◽

Hideyasu Okamura ◽

Takehiro K. Sato ◽

...

Keyword(s):

Mechanical Properties ◽

Formic Acid ◽

Spider Silk ◽

Chemical Shifts ◽

Repetitive Sequences ◽

Silk Protein ◽

Random Coil ◽

Oh Groups ◽

Spider Silk Protein ◽

Turn Structure

Spider dragline silk is a biopolymer with excellent mechanical properties. The development of recombinant spider silk protein (RSP)-based materials with these properties is desirable. Formic acid (FA) is a spinning solvent for regenerated Bombyx mori silk fiber with excellent mechanical properties. To use FA as a spinning solvent for RSP with the sequence of major ampullate spider silk protein from Araneus diadematus, we determined the conformation of RSP in FA using solution NMR to determine the role of FA as a spinning solvent. We assigned 1H, 13C, and 15N chemical shifts to 32-residue repetitive sequences, including polyAla and Gly-rich regions of RSP. Chemical shift evaluation revealed that RSP is in mainly random coil conformation with partially type II β-turn structure in the Gly-Pro-Gly-X motifs of the Gly-rich region in FA, which was confirmed by the 15N NOE data. In addition, formylation at the Ser OH groups occurred in FA. Furthermore, we evaluated the conformation of the as-cast film of RSP dissolved in FA using solid-state NMR and found that β-sheet structure was predominantly formed.

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Basic Mechanical Properties of Spider Silk

Sen i Gakkaishi ◽

10.2115/fiber.69.p_286 ◽

2013 ◽

Vol 69 (9) ◽

pp. P_286-P_292

Author(s):

MARI INOUE

Keyword(s):

Mechanical Properties ◽

Spider Silk

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Novel In Silico Analyses of Repetitive Spider Silk Sequences to Understand the Evolution and Mechanical Properties of Fibrous Protein Materials

Biotechnology Journal ◽

10.1002/biot.201900138 ◽

2019 ◽

Vol 14 (10) ◽

pp. 1900138 ◽

Cited By ~ 1

Author(s):

Dooyup Jung ◽

Yun Jung Yang ◽

Hyung Joon Cha

Keyword(s):

Mechanical Properties ◽

In Silico ◽

Spider Silk ◽

Fibrous Protein ◽

In Silico Analyses

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Physical and mechanical properties of surface modified poly ethylene terephthalate films through low pressure plasma and ultra-violet light

Materials Research Express ◽

10.1088/2053-1591/ab5127 ◽

2019 ◽

Vol 6 (11) ◽

pp. 115350

Author(s):

M Kiruthika ◽

K Nivetha ◽

G Shanmugavelayutham

Keyword(s):

Mechanical Properties ◽

Ethylene Terephthalate ◽

Ultra Violet ◽

Physical And Mechanical Properties ◽

Ultra Violet Light ◽

Violet Light ◽

Poly Ethylene Terephthalate ◽

Low Pressure Plasma ◽

Poly Ethylene ◽

Surface Modified

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UV Irradiated Graphene-Based Nanocomposites: Change in the Mechanical Properties by Local HarmoniX Atomic Force Microscopy Detection

Materials ◽

10.3390/ma12060962 ◽

2019 ◽

Vol 12 (6) ◽

pp. 962 ◽

Cited By ~ 2

Author(s):

Liberata Guadagno ◽

Carlo Naddeo ◽

Marialuigia Raimondo ◽

Vito Speranza ◽

Roberto Pantani ◽

...

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Mechanical Stability ◽

Uv Light ◽

Ultra Violet ◽

Graphene Nanoplatelets ◽

Free Standing ◽

Force Microscopy ◽

Atomic Force ◽

Acquisition Mode

Epoxy based coatings are susceptible to ultra violet (UV) damage and their durability can be significantly reduced in outdoor environments. This paper highlights a relevant property of graphene-based nanoparticles: Graphene Nanoplatelets (GNPs) incorporated in an epoxy-based free-standing film determine a strong decrease of the mechanical damages caused by UV irradiation. The effects of UV light on the morphology and mechanical properties of the solidified nanocharged epoxy films are investigated by Atomic Force Microscopy (AFM), in the acquisition mode “HarmoniX.” Nanometric-resolved maps of the mechanical properties of the multi-phase material evidence that the incorporation of low percentages, between 0.1% and 1.0% by weight, of graphene nanoplatelets (GNPs) in the polymeric film causes a relevant enhancement in the mechanical stability of the irradiated films. The beneficial effect progressively increases with increasing GNP percentage. The paper also highlights the potentiality of AFM microscopy, in the acquisition mode “HarmoniX” for studying multiphase polymeric systems.

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