106 research outputs found
Fabrication of Spherical Multi-Hollow TiO<sub>2</sub> Nanostructures for Photoanode Film with Enhanced Light-Scattering Performance
Spherical multihollow (MH) TiO<sub>2</sub> nanostructures
have
been synthesized via a microemulsion-based approach with titanium
glycerolate complexes formation at glycerol microemulsions interface.
The self-aggregation of those microemulsions induces the formation
of MH TiO<sub>2</sub> nanospheres. Owing to this hierarchical hollow
structure, photoanode films derived from MH TiO<sub>2</sub> nanosphere
as light scattering layer exhibits an enhanced light harvesting efficiency,
thus leading to a 43% increment of photovoltaic performance compared
to that from P25 nanoparticle film
Construction of Multifunctional Hydrogels via a Supramolecular Self-Assembled Strategy with Ultrahigh Sensitivity to Strain Responsiveness
Intelligent electronic devices have been diffusely used
in health
detection, energy storage, and biomedicine based on their autonomy,
flexibility, and adaptive improvement, but traditional materials have
the drawbacks of limited flexibility, instability, and inadequate
reusability. Herein, poly(acrylic acid)-based hydrogels with efficient
self-healing performance and high-precision sensing performance were
constructed by a supramolecular self-assembled strategy based on electrostatic
interactions, metal coordination, and hydrogen bonds. This hydrogel
exhibited a tensile strength of 102.9 kPa and an elongation at break
of 990% with good fatigue resistance and self-recovery ability. The
hydrogel also displayed good light transmission and UV-shielding effects,
as well as good adhesion ability on different materials. Besides,
the hydrogel had an electrical conductivity of 0.98 S/m, which could
light up a light-emitting diode (LED) bulb when connected in a circuit.
Based on these great features, the hydrogel exhibited ultrahigh sensitivity
with gauge factor values of 4.00 and 17.00 within the strain ranges
of 0–200 and 600–800%, respectively. The hydrogel could
be applied not only for large human movements but also for detecting
subtle movements. Most importantly, the hydrogel exhibited a great
self-healing property, which could almost self-heal within 6 h with
a healing efficiency of 99%. Therefore, this work provides a multifunctional
hydrogel construction method, and the prepared hydrogels displayed
great potential application in the strain sensor field
Construction of Multifunctional Hydrogels via a Supramolecular Self-Assembled Strategy with Ultrahigh Sensitivity to Strain Responsiveness
Intelligent electronic devices have been diffusely used
in health
detection, energy storage, and biomedicine based on their autonomy,
flexibility, and adaptive improvement, but traditional materials have
the drawbacks of limited flexibility, instability, and inadequate
reusability. Herein, poly(acrylic acid)-based hydrogels with efficient
self-healing performance and high-precision sensing performance were
constructed by a supramolecular self-assembled strategy based on electrostatic
interactions, metal coordination, and hydrogen bonds. This hydrogel
exhibited a tensile strength of 102.9 kPa and an elongation at break
of 990% with good fatigue resistance and self-recovery ability. The
hydrogel also displayed good light transmission and UV-shielding effects,
as well as good adhesion ability on different materials. Besides,
the hydrogel had an electrical conductivity of 0.98 S/m, which could
light up a light-emitting diode (LED) bulb when connected in a circuit.
Based on these great features, the hydrogel exhibited ultrahigh sensitivity
with gauge factor values of 4.00 and 17.00 within the strain ranges
of 0–200 and 600–800%, respectively. The hydrogel could
be applied not only for large human movements but also for detecting
subtle movements. Most importantly, the hydrogel exhibited a great
self-healing property, which could almost self-heal within 6 h with
a healing efficiency of 99%. Therefore, this work provides a multifunctional
hydrogel construction method, and the prepared hydrogels displayed
great potential application in the strain sensor field
Construction of Multifunctional Hydrogels via a Supramolecular Self-Assembled Strategy with Ultrahigh Sensitivity to Strain Responsiveness
Intelligent electronic devices have been diffusely used
in health
detection, energy storage, and biomedicine based on their autonomy,
flexibility, and adaptive improvement, but traditional materials have
the drawbacks of limited flexibility, instability, and inadequate
reusability. Herein, poly(acrylic acid)-based hydrogels with efficient
self-healing performance and high-precision sensing performance were
constructed by a supramolecular self-assembled strategy based on electrostatic
interactions, metal coordination, and hydrogen bonds. This hydrogel
exhibited a tensile strength of 102.9 kPa and an elongation at break
of 990% with good fatigue resistance and self-recovery ability. The
hydrogel also displayed good light transmission and UV-shielding effects,
as well as good adhesion ability on different materials. Besides,
the hydrogel had an electrical conductivity of 0.98 S/m, which could
light up a light-emitting diode (LED) bulb when connected in a circuit.
Based on these great features, the hydrogel exhibited ultrahigh sensitivity
with gauge factor values of 4.00 and 17.00 within the strain ranges
of 0–200 and 600–800%, respectively. The hydrogel could
be applied not only for large human movements but also for detecting
subtle movements. Most importantly, the hydrogel exhibited a great
self-healing property, which could almost self-heal within 6 h with
a healing efficiency of 99%. Therefore, this work provides a multifunctional
hydrogel construction method, and the prepared hydrogels displayed
great potential application in the strain sensor field
Versatile Synthesis of Multiarm and Miktoarm Star Polymers with a Branched Core by Combination of Menschutkin Reaction and Controlled Polymerization
Menschutkin reaction and controlled polymerization were
combined
to construct three types of star polymers with a branched core. Branched
PVD was synthesized by reversible addition–fragmentation chain
transfer (RAFT) copolymerization and used as a core reagent to synthesize
multiarm and miktoarm stars with poly(ε-caprolactone) (PCL),
polystyrene, poly(methyl methacrylate), poly(<i>tert</i>-butyl acrylate), and poly(<i>N</i>-isopropylacrylamide)
segments. Effects of reaction time, feed ratio, and arm length on
coupling reaction between PVD and bromide-functionalized polymer were
investigated, and a variety of A<sub><i>m</i></sub>-type
stars (<i>m</i> ≈ 7.0–35.1) were obtained.
Meanwhile, A<sub><i>m</i></sub>B<sub><i>n</i></sub> stars (<i>m</i> ≈ 9.0, <i>n</i> ≈
6.1–11.3) were achieved by successive Menschutkin reactions,
and A<sub><i>m</i></sub>C<sub><i>o</i></sub> stars
(<i>m</i> ≈ 8.8–9.0, <i>o</i> ≈
5.0) were generated by tandem quaternization and RAFT processes. Molecular
weights of various stars usually agreed well with the theoretical
values, and their polydispersity indices were in the range of 1.06–1.24.
The arm number, chain length, and chemical composition of star polymers
could be roughly adjusted by control over reaction conditions and
utilization of alternative methods, revealing the generality and versatility
of these approaches. These ion-bearing stars were liable to exhibit
solubility different from normal covalently bonded polymers, and the
chain relaxation and melting behaviors of polymer segments were strongly
dependent on the macromolecular architecture
Construction of Multifunctional Hydrogels via a Supramolecular Self-Assembled Strategy with Ultrahigh Sensitivity to Strain Responsiveness
Intelligent electronic devices have been diffusely used
in health
detection, energy storage, and biomedicine based on their autonomy,
flexibility, and adaptive improvement, but traditional materials have
the drawbacks of limited flexibility, instability, and inadequate
reusability. Herein, poly(acrylic acid)-based hydrogels with efficient
self-healing performance and high-precision sensing performance were
constructed by a supramolecular self-assembled strategy based on electrostatic
interactions, metal coordination, and hydrogen bonds. This hydrogel
exhibited a tensile strength of 102.9 kPa and an elongation at break
of 990% with good fatigue resistance and self-recovery ability. The
hydrogel also displayed good light transmission and UV-shielding effects,
as well as good adhesion ability on different materials. Besides,
the hydrogel had an electrical conductivity of 0.98 S/m, which could
light up a light-emitting diode (LED) bulb when connected in a circuit.
Based on these great features, the hydrogel exhibited ultrahigh sensitivity
with gauge factor values of 4.00 and 17.00 within the strain ranges
of 0–200 and 600–800%, respectively. The hydrogel could
be applied not only for large human movements but also for detecting
subtle movements. Most importantly, the hydrogel exhibited a great
self-healing property, which could almost self-heal within 6 h with
a healing efficiency of 99%. Therefore, this work provides a multifunctional
hydrogel construction method, and the prepared hydrogels displayed
great potential application in the strain sensor field
Construction of Multifunctional Hydrogels via a Supramolecular Self-Assembled Strategy with Ultrahigh Sensitivity to Strain Responsiveness
Intelligent electronic devices have been diffusely used
in health
detection, energy storage, and biomedicine based on their autonomy,
flexibility, and adaptive improvement, but traditional materials have
the drawbacks of limited flexibility, instability, and inadequate
reusability. Herein, poly(acrylic acid)-based hydrogels with efficient
self-healing performance and high-precision sensing performance were
constructed by a supramolecular self-assembled strategy based on electrostatic
interactions, metal coordination, and hydrogen bonds. This hydrogel
exhibited a tensile strength of 102.9 kPa and an elongation at break
of 990% with good fatigue resistance and self-recovery ability. The
hydrogel also displayed good light transmission and UV-shielding effects,
as well as good adhesion ability on different materials. Besides,
the hydrogel had an electrical conductivity of 0.98 S/m, which could
light up a light-emitting diode (LED) bulb when connected in a circuit.
Based on these great features, the hydrogel exhibited ultrahigh sensitivity
with gauge factor values of 4.00 and 17.00 within the strain ranges
of 0–200 and 600–800%, respectively. The hydrogel could
be applied not only for large human movements but also for detecting
subtle movements. Most importantly, the hydrogel exhibited a great
self-healing property, which could almost self-heal within 6 h with
a healing efficiency of 99%. Therefore, this work provides a multifunctional
hydrogel construction method, and the prepared hydrogels displayed
great potential application in the strain sensor field
Synthesis and Properties of Multicleavable Amphiphilic Dendritic Comblike and Toothbrushlike Copolymers Comprising Alternating PEG and PCL Grafts
Facile construction of novel functional dendritic copolymers
by
combination of self-condensing vinyl polymerization, sequence-controlled
copolymerization and RAFT process was presented. RAFT copolymerization
of a disulfide-linked polymerizable RAFT agent and equimolar feed
ratio of styrenic and maleimidic macromonomers afforded multicleavable
A<sub><i>m</i></sub>B<sub><i>n</i></sub> dendritic
comblike copolymers with alternating PEG (A) and PCL (B) grafts, and
a subsequent chain extension polymerization of styrene, <i>tert</i>-butyl acrylate, methyl methacrylate, and <i>N</i>-isopropylacrylamide
gave A<sub><i>m</i></sub>B<sub><i>n</i></sub>C<sub><i>o</i></sub> dendritic toothbrushlike copolymers. (PEG)<sub><i>m</i></sub>(PCL)<sub><i>n</i></sub> copolymers
obtained were of adjustable molecular weight, relatively low polydispersity
(PDI = 1.10–1.32), variable CTA functionality (<i>f</i><sub>CTA</sub> = 4.3–7.5), and similar segment numbers of
PEG and PCL grafts, evident from <sup>1</sup>H NMR and GPC-MALLS analyses.
Their branched architecture was confirmed by (a) reduction-triggered
degradation, (b) decreased intrinsic viscosities and Mark–Houwink–Sakurada
exponent than their “linear” analogue, and (c) lowered
glass transition and melting temperatures and broadened melting range
as compared with normal A<sub><i>m</i></sub>B<sub><i>n</i></sub> comblike copolymer. In vitro drug release results
revealed that the drug release kinetics of the disulfide-linked A<sub><i>m</i></sub>B<sub><i>n</i></sub> copolymer
aggregates was significantly affected by macromolecular architecture,
end group and reductive stimulus. These stimuli-responsive and biodegradable
dendritic copolymer aggregates had a great potential as controlled
delivery vehicles
PAMAM Dendrimer-Baculovirus Nanocomplex for Microencapsulated Adipose Stem Cell-Gene Therapy: <i>In Vitro</i> and <i>in Vivo</i> Functional Assessment
The present study aims to develop a new stem cell based
gene delivery
system consisting of human adipose tissue derived stem cells (hASCs)
genetically modified with self-assembled nanocomplex of recombinant
baculovirus and PAMAM dendrimer (Bac-PAMAM) to overexpress the vascular
endothelial growth factor (VEGF). Cells were enveloped into branched
PEG surface functionalized polymeric microcapsules for efficient transplantation. <i>In vitro</i> analysis confirmed efficient transduction of hASCs
expressing 7.65 ± 0.86 ng functionally active VEGF per 10<sup>6</sup> microencapsulated hASCs (ASC-VEGF). To determine the potential
of the developed system, chronically infarcted rat hearts were treated
with either empty microcapsules (MC), microencapsulated hASCs expressing
MGFP reporter protein (MC+ASC-MGFP), or MC+ASC-VEGF, and analyzed
for 10 weeks. Post-transplantation data confirmed higher myocardial
VEGF expressions with significantly enhanced neovasculature in the
MC+ASC-VEGF group. In addition, the cardiac performance, as measured
by percentage ejection fraction, also improved significantly in the
MC+ASC-VEGF group (48.6 ± 6.1%) compared to that in MC+ASC-MGFP
(38.8 ± 5.3%) and MC groups (31.5 ± 3.3%). Collectively,
these data demonstrate the feasibility of this system for improved
stem cell therapy applications
Revealing the Structure–Luminescence Relationship in Robust Sn(IV)-Based Metal Halides by Sb<sup>3+</sup> Doping
Low-dimensional
hybrid metal halides are an emerging class of materials
with highly efficient photoluminescence (PL), but the problems of
poor stability remain challenging. Sn(IV)-based metal halides show
robust structure but exhibit poor PL properties, and the structure–luminescence
relationship is elusive. Herein, two Sn(IV)-based metal halides (compounds 1 and 2) with the same constituent ((C6H16N2)SnCl6) but different crystal
structures have been prepared, which however show poor PL properties
at room temperature due to the absence of active ns2 electrons.
To improve materials’ PL properties, Sb3+ with active
5s2 electrons was embedded into the lattice of Sn4+-based hosts. As a result, efficient emissions were achieved for
Sb3+-doped compounds 1 and 2 with
a maximum PL efficiency of 14.28 and 62%, respectively. Experimental
and calculation results reveal that the smaller distorted lattice
structure of the host could result in the blueshift of the emission
from Sb3+. Thus, a tunable color from red to orange was
realized. Benefiting from the broadband efficient emission from Sb3+-doped compound 2, an efficient white light-emitting
diode with a high color rendering index of up to 92.3 was fabricated
to demonstrate its lighting application potential. This work promotes
the understanding of the influence of robust Sn(IV)-based host lattice
on the PL properties of Sb3+, advancing the development
of environmentally friendly, low-cost, and high-efficiency Sn(IV)-based
metal halides
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