32 research outputs found
The Quest to Quit: an Exploration of the Cessation - Relapse Cycle of Cigarette Smoking
The smoker's perspective is seldom sought in cessation research. Consequently, cessation approaches may be less effective because they are not based on assumptions and interpretations shared by those who smoke. Understanding how chronic relapsing smokers interpret their predicament could enhance cessation approaches,
improving the chances for complete, permanent cessation. To generate such an understanding, five participants were recruited who had attempted to quit smoking several times. Aiming for depth rather than breadth, multiple interviews were conducted with each participant, who also kept an event diary, recording current smoking,
nicotine withdrawal, lapsing and relapsing. Narratology, a biographical method of symbolic interactionism drawing on thematic, structural, and dialogic analysis, was used to elicit the participants' points of view from interview and diary data. The findings show that participants make sense of their chronic relapsing through a master narrative of 'willpower versus weakness'. Meanwhile, the tobacco control domain is largely driven by 'cost', and subsidised treatments are driven by the 'addiction' master narrative. This gap between ways of making sense of smoking and relapse can cause self-stigma, reducing the likelihood that quitting will be attempted and that quit attempts will succeed. Changes are proposed to mitigate the negative effects on self-efficacy
brought about through the present approach to tobacco control. Ways to improve the effectiveness of existing treatments are suggested. Finally, the value of the narrative method is highlighted, with suggestions for its use in research where elucidating the insider
point of view may improve treatment outcomes
Dialysis-Free and in Situ Doping Synthesis of Polypyrrole@Cellulose Nanowhiskers Nanohybrid for Preparation of Conductive Nanocomposites with Enhanced Properties
The separation of cellulose nanowhiskers
(CNs) from hydrolysis
acid and the harmless disposal of the residual hydrolysis acid are
two main obstacles that hinder the large-scale production of CNs and
CNs based nanocomposites. In this work, the hydrolysis products of
CNs without further separation were used as the starting materials
for preparation of a CNs supported polypyrrole (PPy@CNs) nanohybrid.
During this one-pot synthesis process, the residual hydrolysis acid
acted as a doping agent for the synthesized PPy, endowing PPy@CNs
nanohybrid with electrical conductivity. Interestingly, the PPy@CNs
nanohybrid could be easily isolated from the polymerization products
due to the decreased surface charge. Meanwhile, the PPy@CNs nanohybrid
showed good suspension stability in alkaline natural rubber (NR) latex,
which facilitated the construction of continuous PPy@CNs conductive
network in the NR matrix. This PPy@CNs filled NR nanocomposite showed
significant improvement in electrical conductivity and mechanical
properties when compared with neat PPy/NR composites, and exhibited
similar performance to that of PPy@CNs-0 (CNs was isolated by dialysis
and virgin doping agent was used) filled NR nanocomposites. The straightforwardness
and sustainability of this dialysis-free and in situ doping synthesis
of the PPy@CNs nanohybrid should significantly facilitate the scalable
fabrication and application of CNs based conductive nanocomposites
with high performance
Spirally Structured Conductive Composites for Highly Stretchable, Robust Conductors and Sensors
Flexible and stretchable electronics
are highly desirable for next
generation devices. However, stretchability and conductivity are fundamentally
difficult to combine for conventional conductive composites, which
restricts their widespread applications especially as stretchable
electronics. Here, we innovatively develop a new class of highly stretchable
and robust conductive composites via a simple and scalable structural
approach. Briefly, carbon nanotubes are spray-coated onto a self-adhesive
rubber film, followed by rolling up the film completely to create
a spirally layered structure within the composites. This unique spirally
layered structure breaks the typical trade-off between stretchability
and conductivity of traditional conductive composites and, more importantly,
restrains the generation and propagation of mechanical microcracks
in the conductive layer under strain. Benefiting from such structure-induced
advantages, the spirally layered composites exhibit high stretchability
and flexibility, good conductive stability, and excellent robustness,
enabling the composites to serve as highly stretchable conductors
(up to 300% strain), versatile sensors for monitoring both subtle
and large human activities, and functional threads for wearable electronics.
This novel and efficient methodology provides a new design philosophy
for manufacturing not only stretchable conductors and sensors but
also other stretchable electronics, such as transistors, generators,
artificial muscles, etc
Highly Sensitive, Stretchable, and Wash-Durable Strain Sensor Based on Ultrathin Conductive Layer@Polyurethane Yarn for Tiny Motion Monitoring
Strain
sensors play an important role in the next generation of
artificially intelligent products. However, it is difficult to achieve
a good balance between the desirable performance and the easy-to-produce
requirement of strain sensors. In this work, we proposed a simple,
cost-efficient, and large-area compliant strategy for fabricating
highly sensitive strain sensor by coating a polyurethane (PU) yarn
with an ultrathin, elastic, and robust conductive polymer composite
(CPC) layer consisting of carbon black and natural rubber. This CPC@PU
yarn strain sensor exhibited high sensitivity with a gauge factor
of 39 and detection limit of 0.1% strain. The elasticity and robustness
of the CPC layer endowed the sensor with good reproducibility over
10 000 cycles and excellent wash- and corrosion-resistance.
We confirmed the applicability of our strain sensor in monitoring
tiny human motions. The results indicated that tiny normal physiological
activities (including pronunciation, pulse, expression, swallowing,
coughing, etc.) could be monitored using this CPC@PU sensor in real
time. In particular, the pronunciation could be well parsed from the
recorded delicate speech patterns, and the emotions of laughing and
crying could be detected and distinguished using this sensor. Moreover,
this CPC@PU strain-sensitive yarn could be woven into textiles to
produce functional electronic fabrics. The high sensitivity and washing
durability of this CPC@PU yarn strain sensor, together with its low-cost,
simplicity, and environmental friendliness in fabrication, open up
new opportunities for cost-efficient fabrication of high performance
strain sensing devices
Self-Healing, Highly Sensitive Electronic Sensors Enabled by Metal–Ligand Coordination and Hierarchical Structure Design
Electronic sensors
capable of capturing mechanical deformation are highly desirable for
the next generation of artificial intelligence products. However,
it remains a challenge to prepare self-healing, highly sensitive,
and cost-efficient sensors for both tiny and large human motion monitoring.
Here, a new kind of self-healing, sensitive, and versatile strain
sensors has been developed by combining metal–ligand chemistry
with hierarchical structure design. Specifically, a self-healing and
nanostructured conductive layer is deposited onto a self-healing elastomer
substrate cross-linked by metal–ligand coordinate bonds, forming
a hierarchically structured sensor. The resultant sensors exhibit
high sensitivity, low detection limit (0.05% strain), remarkable self-healing
capability, as well as excellent reproducibility. Notably, the self-healed
sensors are still capable to precisely capture not only tiny physiological
activities (such as speech, swallowing, and coughing) but also large
human motions (finger and neck bending, touching). Moreover, harsh
treatments, including bending over 50000 times and mechanical washing,
could not influence the sensitivity and stability of the self-healed
sensors in human motion monitoring. This proposed strategy via alliance
of metal–ligand chemistry and hierarchical structure design
represents a general approach to manufacturing self-healing, robust
sensors, and other electronic devices
Spirally Structured Conductive Composites for Highly Stretchable, Robust Conductors and Sensors
Flexible and stretchable electronics
are highly desirable for next
generation devices. However, stretchability and conductivity are fundamentally
difficult to combine for conventional conductive composites, which
restricts their widespread applications especially as stretchable
electronics. Here, we innovatively develop a new class of highly stretchable
and robust conductive composites via a simple and scalable structural
approach. Briefly, carbon nanotubes are spray-coated onto a self-adhesive
rubber film, followed by rolling up the film completely to create
a spirally layered structure within the composites. This unique spirally
layered structure breaks the typical trade-off between stretchability
and conductivity of traditional conductive composites and, more importantly,
restrains the generation and propagation of mechanical microcracks
in the conductive layer under strain. Benefiting from such structure-induced
advantages, the spirally layered composites exhibit high stretchability
and flexibility, good conductive stability, and excellent robustness,
enabling the composites to serve as highly stretchable conductors
(up to 300% strain), versatile sensors for monitoring both subtle
and large human activities, and functional threads for wearable electronics.
This novel and efficient methodology provides a new design philosophy
for manufacturing not only stretchable conductors and sensors but
also other stretchable electronics, such as transistors, generators,
artificial muscles, etc
Highly Sensitive, Stretchable, and Wash-Durable Strain Sensor Based on Ultrathin Conductive Layer@Polyurethane Yarn for Tiny Motion Monitoring
Strain
sensors play an important role in the next generation of
artificially intelligent products. However, it is difficult to achieve
a good balance between the desirable performance and the easy-to-produce
requirement of strain sensors. In this work, we proposed a simple,
cost-efficient, and large-area compliant strategy for fabricating
highly sensitive strain sensor by coating a polyurethane (PU) yarn
with an ultrathin, elastic, and robust conductive polymer composite
(CPC) layer consisting of carbon black and natural rubber. This CPC@PU
yarn strain sensor exhibited high sensitivity with a gauge factor
of 39 and detection limit of 0.1% strain. The elasticity and robustness
of the CPC layer endowed the sensor with good reproducibility over
10 000 cycles and excellent wash- and corrosion-resistance.
We confirmed the applicability of our strain sensor in monitoring
tiny human motions. The results indicated that tiny normal physiological
activities (including pronunciation, pulse, expression, swallowing,
coughing, etc.) could be monitored using this CPC@PU sensor in real
time. In particular, the pronunciation could be well parsed from the
recorded delicate speech patterns, and the emotions of laughing and
crying could be detected and distinguished using this sensor. Moreover,
this CPC@PU strain-sensitive yarn could be woven into textiles to
produce functional electronic fabrics. The high sensitivity and washing
durability of this CPC@PU yarn strain sensor, together with its low-cost,
simplicity, and environmental friendliness in fabrication, open up
new opportunities for cost-efficient fabrication of high performance
strain sensing devices
Flame Retardant, Heat Insulating Cellulose Aerogels from Waste Cotton Fabrics by in Situ Formation of Magnesium Hydroxide Nanoparticles in Cellulose Gel Nanostructures
Cellulose aerogels with low density,
high mechanical strength,
and low thermal conductivity are promising candidates for environmentally
friendly heat insulating materials. The application of cellulose aerogels
as heat insulators in building and domestic appliances, however, is
hampered by their highly flammable characteristics. In this work,
flame retardant cellulose aerogels were fabricated from waste cotton
fabrics by in situ synthesis of magnesium hydroxide nanoparticles
(MH NPs) in cellulose gel nanostructures, followed by freeze-drying.
Our results demonstrated that the three-dimensionally nanoporous cellulose
gel prepared from the NaOH/urea solution could serve as scaffold/template
for the nonagglomerated growth of MH NPs. The prepared hybridized
cellulose aerogels showed excellent flame retardancy, which could
extinguish within 40 s. Meanwhile, the thermal conductivity of the
composite aerogel increased moderately from 0.056 to 0.081 W m<sup>–1</sup> k<sup>–1</sup> as the specific surface area
decreased slightly from 38.8 to 37.6 cm<sup>2</sup> g<sup>–1</sup>, which indicated that the excellent heat insulating performance
of cellulose aerogel was maintained. Because the concepts of the process
are simple and biomass wastes are sustainable and readily available
at low cost, the present approach is suitable for industrial scale
production and has great potential in the future of green building
materials
Spontaneous and Simultaneous Oxidation and Reduction of <i>o</i>‑Quinones in Water Microdroplets
Microdroplet
chemistry has been an emerging new field for its large
plethora of unique properties, among which an especially intriguing
one is the strong oxidizing and reducing powers. The hydroxide ion
in water microdroplets is considered to split into a hydroxyl radical
and an electron at the air–water interface, and the former
is responsible for the oxidizing capability while the latter is responsible
for the reducing power, making a unity of opposites. However, to date
there are only two examples showing that oxidation and reduction occur
simultaneously to the same substrates, which might be a result of
the redox properties of the substrate per se. In
this study, we carefully chose a group of ο-quinone compounds as the substrates in water microdroplets and discovered
that they can be both oxidized by the hydroxyl radical and reduced
by the electron. These results keep pushing the limit of the unique
redox properties of microdroplet chemistry
Dual Functional Biocomposites Based on Polydopamine Modified Cellulose Nanocrystal for Fe<sup>3+</sup>-Pollutant Detecting and Autoblocking
In this work, a facile and sustainable
strategy for ferric ion
(Fe<sup>3+</sup>) detection was developed for the first time based
on a coordination bonding between Fe<sup>3+</sup> and polydopamine
(PDA) modified cellulose nanocrystals (CNC) (PDA@CNC). PDA, as a probe
molecule for Fe<sup>3+</sup> detection, was <i>in situ</i> synthesized onto CNC template via one-pot oxidative polymerization
of biological dopamine, yielding nanosized and well-dispersed PDA@CNC
nanohybrid. When PDA@CNC met Fe<sup>3+</sup>, the coordination bonding
between PDA and Fe<sup>3+</sup> led to rapid agglomeration of PDA@CNC,
resulting in macroscopical and flocculent PDA@CNC aggregates. Interestingly,
this morphology transition of PDA@CNC enabled on-site detection of
Fe<sup>3+</sup> with a minimum limit of 3 ppm by the naked eye, which
could be further optimized to 0.5 ppm using a dynamic light scattering
method. Furthermore, we demonstrated another interesting application
of the smart PDA@CNC biocomposites in automatic blockage of wastewater
containing Fe<sup>3+</sup>. This easy and eco-friendly preparation
method for dual functional PDA@CNC biocomposites provides a new strategy
for Fe<sup>3+</sup>-pollutant detecting and autoblocking in a simple
and sustainable way