pH Sensitive Polymeric Binders for Energetic Materials

2017 ◽  
Vol 54 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Andreea Elena Voicu ◽  
Traian Rotariu ◽  
Mircea Teodorescu ◽  
Teodora Zecheru ◽  
Tudor Viorel Tiganescu ◽  
...  

The aim of this research has been to develop a new generation of eco-friendly binders, soluble at alkaline pH, which could allow facile recovery of explosive fillers without using organic solvents, while maintaining their chemical and physical characteristics. For this purpose, �smart� polymeric binders are to be designed based on acrylic acid and other acrylic monomers. In this view, theoretical and experimental studies have been performed in order to establish which synthesized polymer is adequate for the desired application.

Author(s):  
Aleksandr S. MYAKOCHIN ◽  
Petr V. NIKITIN ◽  
Sergey Yu. POBEREZHSKIY ◽  
Anna A. SHKURATENKO

The paper presents a method, tools and a newly developed algorithm for experimentally determining heat transfer coefficients in organic liquids and solutions. This work is made relevant by the problem of development of a new generation of aerospace technology. In this connection, improvements have been made to the pulse method of determining heat transfer coefficients that is based on the use of a micron-thick film sensor. The measurement setup was modified. A math model was constructed for the measuring sensor. Algorithms were developed for conducting the experiment and processing measurement results to determine heat transfer coefficients. Experimental uncertainties were analyzed. The paper provides results of experimental studies on certain organic liquids. The authors believe that the material presented in the paper will find application in research conducted at research institutions, engineering offices and universities, among researches, postgraduates and students. Key words: thermal and physical characteristics, organic liquids and their solutions, film-type electrical resistor, thin-film temperature sensor, voltage pulse, resistance thermometer, irregular heat transfer regime.


MRS Advances ◽  
2019 ◽  
Vol 5 (17) ◽  
pp. 881-889
Author(s):  
Alex Keller ◽  
Holly Warren ◽  
Marc in het Panhuis

ABSTRACTEdible devices are an emergent technology and in this paper the simplicity and efficacy that poly(acrylic acid)/calcium hydroxide possess in creating a pH sensitive ingestible actuator which responds to acidic environments such as gastric fluid is demonstrated. It was found that poly(acrylic acid)/calcium hydroxide hydrogels exhibit reversible actuation upon submerging in 0.1 M sodium citrate for 2 hours. Our results show that these hydrogels can restore their compressive stress to 0.19 ± 0.06 MPa, swelling ratio to 26 ± 2 and volume to 56% ± 3% of its original volume. This work offers new possibilities for developments in a variety of fields such as drug delivery, 4D printed materials, soft robotics and edible devices.


2015 ◽  
Vol 3 (13) ◽  
pp. 2685-2697 ◽  
Author(s):  
Xinyu Hu ◽  
Wei Wei ◽  
Xiaoliang Qi ◽  
Hao Yu ◽  
Liandong Feng ◽  
...  

The pH-sensitive swelling behaviour and DOX release of Salecan-g-PAA hydrogels are discussed.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Ajay K Wakhloo ◽  
Pedro Lylyk ◽  
Joost de Vries ◽  
Matthew J Gounis ◽  
Alexandra Biondi ◽  
...  

Objective: Validated through experimental studies a new generation of flow diverters (Surpass™ FD) was evaluated for treatment of intracranial aneurysms (IA). We present our multicenter preliminary clinical and angiographic experience. METHODS: To achieve the calculated flow disruption between the parent artery and aneurysm for thrombosis, single FDs were placed endovascularly in parent arteries. Implants measured 2.5-5.3mm in diameter with a length of 10-80mm. Patients were enrolled harboring a wide range large and giant wide-neck, fusiform and multiple small and blister-type aneurysm. Clinical and angiographic follow-up were performed at 1-3, 6, and 12 months. RESULTS: A total of 186 consecutive IA in 161 patients (mean age 57.1 years) were treated at 33 centers. Fifty-three aneurysms were smaller than 5 mm, 64 were 5-9.9mm in diameter, 47 were 10-20mm in diameter, and 22 were larger than 20mm (10.4±0.7mm, neck size 6.0±0.5mm [mean±SEM]) . The aneurysms originated in 63.4% from the internal carotid artery; 22% and 14.5% of the lesions were located in the anterior circulation distal to Circle of Willis and posterior circulation respectively. Technical success was achieved in 182 aneurysms (98%); average number of devices used per aneurysm was 1.05. Permanent morbidity and mortality during the follow-up period of mean 8.4months (range 1-24 months) including periprocedural complications for patients with aneurysms of the anterior circulation were encountered in 5 (3.7%) and 2 (1.5 %) patients respectively and 1 (3.7%) and 4 (14.8%) respectively for patients with aneurysms of the posterior circulation location. One-hundred-ten patients (70.5%) harboring 127 (70.2%) were available for clinical and angiographic follow-up and showed a complete or near complete aneurysm occlusion in 63 (81.8%) of the ICA. Aneurysms of the ICA≥10mm that were completely covered by FD and not previously stent-treated with a minimum of 6 months follow-up available in 16 patients showed a complete obliteration in 81.3% (n=13) and >90% occlusion in remaining 3 patients. CONCLUSION: Preliminary data demonstrate high safety and efficacy of a new generation of FD for a wide range of IA of the anterior and posterior circulation with a single implant.


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