Santos admits it took him time to find his feet in the Premier League but says he is enjoying his football at Emirates Stadium after a period of adjustment.
"I believe I needed a little run of games to get used to everything," he told the Official Arsenal Matchday Programme.
"I feel a lot better on the pitch now - I'm getting to know the characteristics of all my team-mates and this is very important for me. I'm learning to position myself better on the pitch and to read the game better as well. All of this comes with experience.
"English football is fast and strong and I think the best in the world - the experience we get here makes each of us get better every day.
"I'm very well and feeling really good here at Arsenal. I would like to thank everyone that helped me to get here, everyone at the Club now, and the fans - who are always behind us.
"I have to say that I'm very happy here and hope to stay here for a long time. I came here to win titles and be victorious, and I'm sure I can achieve that here."