32 research outputs found

    The Quest to Quit: an Exploration of the Cessation - Relapse Cycle of Cigarette Smoking

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    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

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    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

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    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

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    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

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    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

    No full text
    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

    No full text
    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

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    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

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    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

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    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
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