5 research outputs found
BOMBYX MORI SILK: FROM MECHANICAL PROPERTIES TO FUNCTIONALITIES
Ph.DDOCTOR OF PHILOSOPH
Recent Progress in Energy-Driven Water Splitting
Hydrogen is readily obtained from renewable and non-renewable resources via water splitting by using thermal, electrical, photonic and biochemical energy. The major hydrogen production is generated from thermal energy through steam reforming/gasification of fossil fuel. As the commonly used non-renewable resources will be depleted in the long run, there is great demand to utilize renewable energy resources for hydrogen production. Most of the renewable resources may be used to produce electricity for driving water splitting while challenges remain to improve cost-effectiveness. As the most abundant energy resource, the direct conversion of solar energy to hydrogen is considered the most sustainable energy production method without causing pollutions to the environment. In overall, this review briefly summarizes thermolytic, electrolytic, photolytic and biolytic water splitting. It highlights photonic and electrical driven water splitting together with photovoltaic-integrated solar-driven water electrolysis.Published versio
Peptide–Graphene Interactions Enhance the Mechanical Properties of Silk Fibroin
Studies reveal that biomolecules
can form intriguing molecular structures with fascinating functionalities
upon interaction with graphene. Then, interesting questions arise.
How does silk fibroin interact with graphene? Does such interaction
lead to an enhancement in its mechanical properties? In this study,
using large-scale molecular dynamics simulations, we first examine
the interaction of graphene with several typical peptide structures
of silk fibroin extracted from different domains of silk fibroin,
including pure amorphous (P1), pure crystalline (P2), a segment from
N-terminal (P3), and a combined amorphous and crystalline segment
(P4), aiming to reveal their structural modifications. Our study shows
that graphene can have intriguing influences on the structures formed
by the peptides with sequences representing different domains of silk
fibroin. In general, for protein domains with stable structure and
strong intramolecular interaction (e.g., β-sheets), graphene
tends to compete with the intramolecular interactions and thus weaken
the interchain interaction and reduce the contents of β-sheets.
For the silk domains with random or less ordered secondary structures
and weak intramolecular interactions, graphene tends to enhance the
stability of peptide structures; in particular, it increases the contents
of helical structures. Thereafter, tensile simulations were further
performed on the representative peptides to investigate how such structure
modifications affect their mechanical properties. It was found that
the strength and resilience of the peptides are enhanced through their
interaction with graphene. The present work reveals interesting insights
into the interactions between silk peptides and graphene, and contributes
in the efforts to enhance the mechanical properties of silk fibroin
Protein Induces Layer-by-Layer Exfoliation of Transition Metal Dichalcogenides
Here,
we report a general and facile method for effective layer-by-layer
exfoliation of transition metal dichalcogenides (TMDs) and graphite
in water by using protein, bovine serum albumin (BSA) to produce single-layer
nanosheets, which cannot be achieved using other commonly used bio-
and synthetic polymers. Besides serving as an effective exfoliating
agent, BSA can also function as a strong stabilizing agent against
reaggregation of single-layer nanosheets for greatly improving their
biocompatibility in biomedical applications. With significantly increased
surface area, single-layer MoS<sub>2</sub> nanosheets also exhibit
a much higher binding capacity to pesticides and a much larger specific
capacitance. The protein exfoliation process is carefully investigated
with various control experiments and density functional theory simulations.
It is interesting to find that the nonpolar groups of protein can
firmly bind to TMD layers or graphene to expose polar groups in water,
facilitating the effective exfoliation of single-layer nanosheets
in aqueous solution. The present work will enable to optimize the
fabrication of various 2D materials at high yield and large scale,
and bring more opportunities to investigate the unique properties
of 2D materials and exploit their novel applications