Influence of reaction time on properties of regioregular poly(3-hexylthiophene) by the Grignard metathesis polymerization

Non-covalent functionalisation of the carbon nanotube (CNT) sidewall through polymer wrapping is the key strategy for improving well-dispersed CNTs without persistent alteration of their electronic properties. In this work, the effect of reaction time on regioregular poly (3-hexylthiophene-2,5-diyl) (P3HT)-wrapped hydroxylated multi-walled CNT (MWCNT-OH) nanocomposites was investigated. Five different reaction times (24, 48, 72, 96, and 120 h) were conducted at room temperature in order to clearly determine the factors that influenced the quality of wrapped MWCNT-OH. Morphological analysis using Field Emission Scanning Electron Microscopic (FESEM) and High-Resolution Transmission Electron Microscope (HRTEM) analysis showed that P3HT successfully wrapped the MWCNT-OH sidewall, evidenced by the changes in the mean diameter size of the nanocomposites. Results obtained from Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) as well as Thermogravimetric Analysis (TGA) showed a significant effect of the wrapped polymer on the CNT sidewall as the reaction time increased. Overall, the method used during the preparation of P3HT-wrapped MWCNT-OH and the presented results significantly provided a bottom-up approach to determine the effect of different reaction times on polymer wrapping to further expand this material for novel applications, especially chemical sensors.

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Excitability of the cortical motor pathways to homologous muscles during Simple, Choice and Go/No Go reaction time paradigms

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(97)88540-2 ◽

1997 ◽

Vol 103 (1) ◽

pp. 122

Author(s):

L Leocani

Keyword(s):

Reaction Time ◽

Motor Pathways ◽

Cortical Motor

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Standardisation of optically evoked event related potentials and reaction time in children

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(97)88470-6 ◽

1997 ◽

Vol 103 (1) ◽

pp. 109

Author(s):

K Grotemeyer

Keyword(s):

Reaction Time ◽

Event Related Potentials ◽

Related Potentials

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REACTION TIME AND INTELLIGENCE

High Ability Studies ◽

10.1080/0937445910010113 ◽

1991 ◽

Vol 1 (1) ◽

pp. 211-221 ◽

Cited By ~ 1

Author(s):

Edward Neçka

Keyword(s):

Reaction Time

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Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽

10.1024/1662-9647/a000045 ◽

2011 ◽

Vol 24 (4) ◽

pp. 169-176 ◽

Cited By ~ 4

Author(s):

Philippe Rast ◽

Daniel Zimprich

Keyword(s):

Reaction Time ◽

Cognitive Aging ◽

Reaction Times ◽

Reaction Time Task ◽

Reaction Time Data ◽

Scale Model ◽

Time Data ◽

Time Task ◽

The Mean ◽

Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

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The Level of Reaction Time Determines the ERP Correlates of Auditory Negative Priming

Journal of Psychophysiology ◽

10.1027/0269-8803.20.3.186 ◽

2006 ◽

Vol 20 (3) ◽

pp. 186-194 ◽

Cited By ~ 14

Author(s):

Susanne Mayr ◽

Michael Niedeggen ◽

Axel Buchner ◽

Guido Orgs

Keyword(s):

Reaction Time ◽

Negative Priming ◽

Effect Size ◽

Priming Effect ◽

Reaction Times ◽

Negative Priming Effect ◽

Episodic Retrieval ◽

Time Level ◽

Fast Reactions ◽

Priming Condition

Responding to a stimulus that had to be ignored previously is usually slowed-down (negative priming effect). This study investigates the reaction time and ERP effects of the negative priming phenomenon in the auditory domain. Thirty participants had to categorize sounds as musical instruments or animal voices. Reaction times were slowed-down in the negative priming condition relative to two control conditions. This effect was stronger for slow reactions (above intraindividual median) than for fast reactions (below intraindividual median). ERP analysis revealed a parietally located negativity of the negative priming condition compared to the control conditions between 550-730 ms poststimulus. This replicates the findings of Mayr, Niedeggen, Buchner, and Pietrowsky (2003) . The ERP correlate was more pronounced for slow trials (above intraindividual median) than for fast trials (below intraindividual median). The dependency of the negative priming effect size on the reaction time level found in the reaction time analysis as well as in the ERP analysis is consistent with both the inhibition as well as the episodic retrieval account of negative priming. A methodological artifact explanation of this effect-size dependency is discussed and discarded.

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Reaction Time and Brain Waves in Omitted Stimulus Tasks

Journal of Psychophysiology ◽

10.1027/0269-8803/a000001 ◽

2010 ◽

Vol 24 (1) ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Oscar H. Hernández ◽

Muriel Vogel-Sprott

Keyword(s):

Reaction Time ◽

Cognitive Processes ◽

Young Male ◽

Event Related Potential ◽

Auditory Stimuli ◽

Motor Action ◽

Cognitive Component ◽

Sensory Modalities ◽

Two Measures ◽

Somatosensory Stimuli

A missing stimulus task requires an immediate response to the omission of a regular recurrent stimulus. The task evokes a subclass of event-related potential known as omitted stimulus potential (OSP), which reflects some cognitive processes such as expectancy. The behavioral response to a missing stimulus is referred to as omitted stimulus reaction time (RT). This total RT measure is known to include cognitive and motor components. The cognitive component (premotor RT) is measured by the time from the missing stimulus until the onset of motor action. The motor RT component is measured by the time from the onset of muscle action until the completion of the response. Previous research showed that RT is faster to auditory than to visual stimuli, and that the premotor of RT to a missing auditory stimulus is correlated with the duration of an OSP. Although this observation suggests that similar cognitive processes might underlie these two measures, no research has tested this possibility. If similar cognitive processes are involved in the premotor RT and OSP duration, these two measures should be correlated in visual and somatosensory modalities, and the premotor RT to missing auditory stimuli should be fastest. This hypothesis was tested in 17 young male volunteers who performed a missing stimulus task, who were presented with trains of auditory, visual, and somatosensory stimuli and the OSP and RT measures were recorded. The results showed that premotor RT and OSP duration were consistently related, and that both measures were shorter with respect to auditory stimuli than to visual or somatosensory stimuli. This provides the first evidence that the premotor RT is related to an attribute of the OSP in all three sensory modalities.

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